Here are the stories our MDedge editors across specialties think you need to know about today:

Could COVID-19 worsen gambling problems?

Take isolation, add excess available time and anxiety about illness or finances and you get the potential to increase problem gambling behaviors during the COVID-19 pandemic. A call to action, recently published in the Journal of Addiction Medicine, says it’s essential to gather data and supply guidance on this issue. “People are likely to be experiencing stress at levels they haven’t experienced previously,” said coauthor Marc N. Potenza, MD, PhD, of Yale University, New Haven, Conn. While multiple factors can contribute to addictive behaviors, “with respect to the pandemic, one concern is that so-called negative reinforcement motivations – engaging in an addictive behavior to escape from depressed or negative mood states – may be a driving motivation for a significant number of people during this time,” he said. Read more.

Food allergies in children are less frequent than expected

Food allergies appear to be less common than previously reported among 6- to 10-year-olds in Europe, according to a recent study. Prevalance ranged from a low of 1.4% to a high of 3.8%, both of which are “considerably lower” than the 16% rate based on parental reports of symptoms such as rash, itching, or diarrhea, Linus Grabenhenrich, MD, MPH, and colleagues reported in Allergy. The most commonly reported allergies were to peanuts and hazelnuts, with a prevalence of just over 5% for both. Previous research on pediatric food allergy prevalence has largely consisted of single-center studies with heterogeneous designs, the researchers noted. Read more.

The grocery store hug

William G. Wilkoff, MD, grew up in a family that didn’t embrace hugging, but as a small-town pediatrician he warmed up to the concept so much that he would frequently hug a passing acquaintance at the grocery store. That’s something he misses in the current environment and that he doesn’t expect will return. “[N]early every week I encounter one or two people with whom I have a long and sometimes emotionally charged relationship,” Dr. Wilkoff wrote in a column on MDedge. “Nurses with whom I sweated over difficult delivery room resuscitations. Parents for whom their anxiety was getting in the way of their ability to parent. Parents and caregivers of complex multiply disabled children who are now adults. Peers who have lost a spouse or a child. I’m sure you have your own list of people who send off that we-need-to-hug spark.” Read more.

Identifying structural lesions of axial spondyloarthritis

What constitutes a structural lesion of the sacroiliac joints on MRI that’s indicative of axial spondyloarthritis (axSpA) has long been a matter of conjecture, but the Assessment of SpondyloArthritis International Society (ASAS) MRI Working Group has developed new definitions that show a high degree of specificity in identifying such lesions in the disease. “Previous studies have described structural lesions in different ways, precluding meaningful comparisons between studies,” Walter P. Maksymowych, MD, said at the annual European Congress of Rheumatology, held online this year due to COVID-19. “The ASAS MRI group has generated updated consensus lesion definitions that describe each of the MRI lesions in the sacroiliac joint. These definitions have been validated by seven expert readers from the ASAS MRI group on MRI images from the ASAS classification cohort.” Read more.

Making the world’s skin crawl

Clinicians should be aware of the skin manifestations of COVID-19, especially when triaging patients. In a commentary published on MDedge, Kathleen M. Coerdt and Amor Khachemoune, MD, describe the dermatologic implications of COVID-19, including the clinical manifestations of the disease, risk reduction techniques for patients and providers, personal protective equipment-associated adverse reactions, and the financial impact on dermatologists. Read more.

For more on COVID-19, visit our Resource Center. All of our latest news is available on MDedge.com.

Here are the stories our MDedge editors across specialties think you need to know about today:

Could COVID-19 worsen gambling problems?

Take isolation, add excess available time and anxiety about illness or finances and you get the potential to increase problem gambling behaviors during the COVID-19 pandemic. A call to action, recently published in the Journal of Addiction Medicine, says it’s essential to gather data and supply guidance on this issue. “People are likely to be experiencing stress at levels they haven’t experienced previously,” said coauthor Marc N. Potenza, MD, PhD, of Yale University, New Haven, Conn. While multiple factors can contribute to addictive behaviors, “with respect to the pandemic, one concern is that so-called negative reinforcement motivations – engaging in an addictive behavior to escape from depressed or negative mood states – may be a driving motivation for a significant number of people during this time,” he said. Read more.

Food allergies in children are less frequent than expected

Food allergies appear to be less common than previously reported among 6- to 10-year-olds in Europe, according to a recent study. Prevalance ranged from a low of 1.4% to a high of 3.8%, both of which are “considerably lower” than the 16% rate based on parental reports of symptoms such as rash, itching, or diarrhea, Linus Grabenhenrich, MD, MPH, and colleagues reported in Allergy. The most commonly reported allergies were to peanuts and hazelnuts, with a prevalence of just over 5% for both. Previous research on pediatric food allergy prevalence has largely consisted of single-center studies with heterogeneous designs, the researchers noted. Read more.

The grocery store hug

William G. Wilkoff, MD, grew up in a family that didn’t embrace hugging, but as a small-town pediatrician he warmed up to the concept so much that he would frequently hug a passing acquaintance at the grocery store. That’s something he misses in the current environment and that he doesn’t expect will return. “[N]early every week I encounter one or two people with whom I have a long and sometimes emotionally charged relationship,” Dr. Wilkoff wrote in a column on MDedge. “Nurses with whom I sweated over difficult delivery room resuscitations. Parents for whom their anxiety was getting in the way of their ability to parent. Parents and caregivers of complex multiply disabled children who are now adults. Peers who have lost a spouse or a child. I’m sure you have your own list of people who send off that we-need-to-hug spark.” Read more.

Identifying structural lesions of axial spondyloarthritis

What constitutes a structural lesion of the sacroiliac joints on MRI that’s indicative of axial spondyloarthritis (axSpA) has long been a matter of conjecture, but the Assessment of SpondyloArthritis International Society (ASAS) MRI Working Group has developed new definitions that show a high degree of specificity in identifying such lesions in the disease. “Previous studies have described structural lesions in different ways, precluding meaningful comparisons between studies,” Walter P. Maksymowych, MD, said at the annual European Congress of Rheumatology, held online this year due to COVID-19. “The ASAS MRI group has generated updated consensus lesion definitions that describe each of the MRI lesions in the sacroiliac joint. These definitions have been validated by seven expert readers from the ASAS MRI group on MRI images from the ASAS classification cohort.” Read more.

Making the world’s skin crawl

Clinicians should be aware of the skin manifestations of COVID-19, especially when triaging patients. In a commentary published on MDedge, Kathleen M. Coerdt and Amor Khachemoune, MD, describe the dermatologic implications of COVID-19, including the clinical manifestations of the disease, risk reduction techniques for patients and providers, personal protective equipment-associated adverse reactions, and the financial impact on dermatologists. Read more.

For more on COVID-19, visit our Resource Center. All of our latest news is available on MDedge.com.

Here are the stories our MDedge editors across specialties think you need to know about today:

Could COVID-19 worsen gambling problems?

Take isolation, add excess available time and anxiety about illness or finances and you get the potential to increase problem gambling behaviors during the COVID-19 pandemic. A call to action, recently published in the Journal of Addiction Medicine, says it’s essential to gather data and supply guidance on this issue. “People are likely to be experiencing stress at levels they haven’t experienced previously,” said coauthor Marc N. Potenza, MD, PhD, of Yale University, New Haven, Conn. While multiple factors can contribute to addictive behaviors, “with respect to the pandemic, one concern is that so-called negative reinforcement motivations – engaging in an addictive behavior to escape from depressed or negative mood states – may be a driving motivation for a significant number of people during this time,” he said. Read more.

Food allergies in children are less frequent than expected

Food allergies appear to be less common than previously reported among 6- to 10-year-olds in Europe, according to a recent study. Prevalance ranged from a low of 1.4% to a high of 3.8%, both of which are “considerably lower” than the 16% rate based on parental reports of symptoms such as rash, itching, or diarrhea, Linus Grabenhenrich, MD, MPH, and colleagues reported in Allergy. The most commonly reported allergies were to peanuts and hazelnuts, with a prevalence of just over 5% for both. Previous research on pediatric food allergy prevalence has largely consisted of single-center studies with heterogeneous designs, the researchers noted. Read more.

The grocery store hug

William G. Wilkoff, MD, grew up in a family that didn’t embrace hugging, but as a small-town pediatrician he warmed up to the concept so much that he would frequently hug a passing acquaintance at the grocery store. That’s something he misses in the current environment and that he doesn’t expect will return. “[N]early every week I encounter one or two people with whom I have a long and sometimes emotionally charged relationship,” Dr. Wilkoff wrote in a column on MDedge. “Nurses with whom I sweated over difficult delivery room resuscitations. Parents for whom their anxiety was getting in the way of their ability to parent. Parents and caregivers of complex multiply disabled children who are now adults. Peers who have lost a spouse or a child. I’m sure you have your own list of people who send off that we-need-to-hug spark.” Read more.

Identifying structural lesions of axial spondyloarthritis

What constitutes a structural lesion of the sacroiliac joints on MRI that’s indicative of axial spondyloarthritis (axSpA) has long been a matter of conjecture, but the Assessment of SpondyloArthritis International Society (ASAS) MRI Working Group has developed new definitions that show a high degree of specificity in identifying such lesions in the disease. “Previous studies have described structural lesions in different ways, precluding meaningful comparisons between studies,” Walter P. Maksymowych, MD, said at the annual European Congress of Rheumatology, held online this year due to COVID-19. “The ASAS MRI group has generated updated consensus lesion definitions that describe each of the MRI lesions in the sacroiliac joint. These definitions have been validated by seven expert readers from the ASAS MRI group on MRI images from the ASAS classification cohort.” Read more.

Making the world’s skin crawl

Clinicians should be aware of the skin manifestations of COVID-19, especially when triaging patients. In a commentary published on MDedge, Kathleen M. Coerdt and Amor Khachemoune, MD, describe the dermatologic implications of COVID-19, including the clinical manifestations of the disease, risk reduction techniques for patients and providers, personal protective equipment-associated adverse reactions, and the financial impact on dermatologists. Read more.

For more on COVID-19, visit our Resource Center. All of our latest news is available on MDedge.com.

During a 4-week period early in the COVID-19 pandemic, visits to U.S. emergency departments were down by 42%, compared with the corresponding period in 2019, according to a report from the Centers for Disease Control and Prevention.

“The striking decline in ED visits nationwide … suggests that the pandemic has altered the use of the ED by the public,” Kathleen P. Hartnett, PhD, and associates at the CDC said June 3 in the Mortality and Morbidity Weekly Report.

The weekly mean was just over 1.2 million ED visits for the 4 weeks from March 29 to April 25, 2020, compared with the nearly 2.2 million visits per week recorded from March 31 to April 27, 2019 – a drop of 42%, based on an analysis of data from the National Syndromic Surveillance Program.

Despite that drop, ED visits for infectious disease–related reasons, taken as a proportion of all 1.2 ED visits during the early pandemic period, were 3.8 times higher than the comparison period in 2019, the investigators reported.

ED visits also were higher in 2020 for specified and unspecified lower respiratory disease not including influenza, pneumonia, asthma, or bronchitis (prevalence ratio of 1.99, compared with 2019), cardiac arrest and ventricular fibrillation (PR, 1.98), and pneumonia not caused by tuberculosis (PR, 1.91), Dr. Hartnett and associates said.

Prevalence ratios for the early pandemic period were down for most other conditions, with some of the largest decreases seen for influenza (PR, 0.16), otitis media (PR, 0.35), and neoplasm-related encounters (PR, 0.40), they said.

Visits have increased each week since reaching their lowest point during April 12-18, but the number for the most recent full week, May 24-30, which was not included in the analysis, was still 26% lower than the corresponding week in 2019, the CDC team pointed out.

“Some persons could be delaying care for conditions that might result in additional mortality if left untreated,” the investigators noted, and those “who use the ED as a safety net because they lack access to primary care and telemedicine might be disproportionately affected if they avoid seeking care because of concerns about the infection risk in the ED.”

[email protected]

SOURCE: Hartnett KP et al. MMWR. 2020 Jun 3. 69:1-6.

During a 4-week period early in the COVID-19 pandemic, visits to U.S. emergency departments were down by 42%, compared with the corresponding period in 2019, according to a report from the Centers for Disease Control and Prevention.

“The striking decline in ED visits nationwide … suggests that the pandemic has altered the use of the ED by the public,” Kathleen P. Hartnett, PhD, and associates at the CDC said June 3 in the Mortality and Morbidity Weekly Report.

The weekly mean was just over 1.2 million ED visits for the 4 weeks from March 29 to April 25, 2020, compared with the nearly 2.2 million visits per week recorded from March 31 to April 27, 2019 – a drop of 42%, based on an analysis of data from the National Syndromic Surveillance Program.

Despite that drop, ED visits for infectious disease–related reasons, taken as a proportion of all 1.2 ED visits during the early pandemic period, were 3.8 times higher than the comparison period in 2019, the investigators reported.

ED visits also were higher in 2020 for specified and unspecified lower respiratory disease not including influenza, pneumonia, asthma, or bronchitis (prevalence ratio of 1.99, compared with 2019), cardiac arrest and ventricular fibrillation (PR, 1.98), and pneumonia not caused by tuberculosis (PR, 1.91), Dr. Hartnett and associates said.

Prevalence ratios for the early pandemic period were down for most other conditions, with some of the largest decreases seen for influenza (PR, 0.16), otitis media (PR, 0.35), and neoplasm-related encounters (PR, 0.40), they said.

Visits have increased each week since reaching their lowest point during April 12-18, but the number for the most recent full week, May 24-30, which was not included in the analysis, was still 26% lower than the corresponding week in 2019, the CDC team pointed out.

“Some persons could be delaying care for conditions that might result in additional mortality if left untreated,” the investigators noted, and those “who use the ED as a safety net because they lack access to primary care and telemedicine might be disproportionately affected if they avoid seeking care because of concerns about the infection risk in the ED.”

[email protected]

SOURCE: Hartnett KP et al. MMWR. 2020 Jun 3. 69:1-6.

During a 4-week period early in the COVID-19 pandemic, visits to U.S. emergency departments were down by 42%, compared with the corresponding period in 2019, according to a report from the Centers for Disease Control and Prevention.

“The striking decline in ED visits nationwide … suggests that the pandemic has altered the use of the ED by the public,” Kathleen P. Hartnett, PhD, and associates at the CDC said June 3 in the Mortality and Morbidity Weekly Report.

The weekly mean was just over 1.2 million ED visits for the 4 weeks from March 29 to April 25, 2020, compared with the nearly 2.2 million visits per week recorded from March 31 to April 27, 2019 – a drop of 42%, based on an analysis of data from the National Syndromic Surveillance Program.

Despite that drop, ED visits for infectious disease–related reasons, taken as a proportion of all 1.2 ED visits during the early pandemic period, were 3.8 times higher than the comparison period in 2019, the investigators reported.

ED visits also were higher in 2020 for specified and unspecified lower respiratory disease not including influenza, pneumonia, asthma, or bronchitis (prevalence ratio of 1.99, compared with 2019), cardiac arrest and ventricular fibrillation (PR, 1.98), and pneumonia not caused by tuberculosis (PR, 1.91), Dr. Hartnett and associates said.

Prevalence ratios for the early pandemic period were down for most other conditions, with some of the largest decreases seen for influenza (PR, 0.16), otitis media (PR, 0.35), and neoplasm-related encounters (PR, 0.40), they said.

Visits have increased each week since reaching their lowest point during April 12-18, but the number for the most recent full week, May 24-30, which was not included in the analysis, was still 26% lower than the corresponding week in 2019, the CDC team pointed out.

“Some persons could be delaying care for conditions that might result in additional mortality if left untreated,” the investigators noted, and those “who use the ED as a safety net because they lack access to primary care and telemedicine might be disproportionately affected if they avoid seeking care because of concerns about the infection risk in the ED.”

[email protected]

SOURCE: Hartnett KP et al. MMWR. 2020 Jun 3. 69:1-6.

The addition of rituximab to standard chemotherapy was a more effective therapy in children and adolescents with high-risk, high-grade,mature B-cell non-Hodgkin lymphoma than the use of chemotherapy alone, according to a study published in the New England Journal of Medicine. The addition of rituximab resulted in long-term complete remission in the vast majority of patients, reported Veronique Minard-Colin, MD, of the Gustave Roussy Institute, Villejuif Cedex, France, and her colleagues on behalf of the European Intergroup for Childhood Non-Hodgkin Lymphoma and the Children’s Oncology Group.

Courtesy Wikimedia Commons/Ed Uthman, MD/Creative Commons License

The researchers performed an open-label, randomized, phase 3 trial of 328 patients younger than 18 years of age with high-risk, mature B-cell non-Hodgkin’s lymphoma (stage III with an elevated lactate dehydrogenase level or stage IV) or acute leukemia to compare the addition of six doses of rituximab to standard lymphomes malins B (LMB) chemotherapy with standard LMB chemotherapy alone. There were 164 patients assigned to each group. The primary end point of the study was event-free survival; overall survival and toxic effects were also followed.

The majority of patients had Burkitt’s lymphoma: 139 (84.8%) in the rituximab-chemotherapy group and 142 (86.6%) in the chemotherapy-alone group, with diffuse large B-cell lymphoma being the second most common cancer: 19 (11.6%) vs. 12 (7.3%), respectively.

Event-free survival at 3 years was 93.9% (95% confidence interval, 89.1-96.7) in the rituximab-chemotherapy group and 82.3% (95% CI, 75.7-87.5) in the chemotherapy group.

Higher 3-year overall survival was also observed (95.1% in the rituximab-chemotherapy group vs. 87.3% in the chemotherapy group; hazard ratio for death, 0.36; 95% CI, 0.16 -0.82).

Eight patients in the rituximab-chemotherapy group died (4 deaths were disease related, 3 were treatment related, and 1 was from a second cancer), as did 20 in the chemotherapy group (17 deaths disease related, and 3 treatment related); HR, 0.36; 95% CI, 0.16-0.82.

The incidence of acute adverse events of grade 4 or higher after prephase treatment was 33.3% in the rituximab-chemotherapy group and 24.2% in the chemotherapy group, a nonsignificant difference (P = .07). However, around twice as many patients in the rituximab-chemotherapy group had a low IgG level at 1 year after trial inclusion, compared with the chemotherapy-alone group, which could indicate the potential for more frequent infections in the long term, the researchers stated.

“An assessment of the long-term effects of combining rituximab with this chemotherapy regimen in children with non-Hodgkin lymphoma, including data on immune status, will be useful,” they added.

The study was funded by the French Ministry of Health, Cancer Research UK, the National Institute for Health Research Clinical Research Network, the Children’s Cancer Foundation Hong Kong, the U.S. National Cancer Institute, and F. Hoffmann–La Roche–Genentech. Several of the authors reported consulting for and institutional and grant funding from F. Hoffmann-LaRoche, which markets rituximab, as well as relationships with other pharmaceutical companies.

[email protected]

SOURCE: Minard-Colin V et al. N Engl J Med. 2020;382:2207-19.

The addition of rituximab to standard chemotherapy was a more effective therapy in children and adolescents with high-risk, high-grade,mature B-cell non-Hodgkin lymphoma than the use of chemotherapy alone, according to a study published in the New England Journal of Medicine. The addition of rituximab resulted in long-term complete remission in the vast majority of patients, reported Veronique Minard-Colin, MD, of the Gustave Roussy Institute, Villejuif Cedex, France, and her colleagues on behalf of the European Intergroup for Childhood Non-Hodgkin Lymphoma and the Children’s Oncology Group.

Courtesy Wikimedia Commons/Ed Uthman, MD/Creative Commons License

The researchers performed an open-label, randomized, phase 3 trial of 328 patients younger than 18 years of age with high-risk, mature B-cell non-Hodgkin’s lymphoma (stage III with an elevated lactate dehydrogenase level or stage IV) or acute leukemia to compare the addition of six doses of rituximab to standard lymphomes malins B (LMB) chemotherapy with standard LMB chemotherapy alone. There were 164 patients assigned to each group. The primary end point of the study was event-free survival; overall survival and toxic effects were also followed.

The majority of patients had Burkitt’s lymphoma: 139 (84.8%) in the rituximab-chemotherapy group and 142 (86.6%) in the chemotherapy-alone group, with diffuse large B-cell lymphoma being the second most common cancer: 19 (11.6%) vs. 12 (7.3%), respectively.

Event-free survival at 3 years was 93.9% (95% confidence interval, 89.1-96.7) in the rituximab-chemotherapy group and 82.3% (95% CI, 75.7-87.5) in the chemotherapy group.

Higher 3-year overall survival was also observed (95.1% in the rituximab-chemotherapy group vs. 87.3% in the chemotherapy group; hazard ratio for death, 0.36; 95% CI, 0.16 -0.82).

Eight patients in the rituximab-chemotherapy group died (4 deaths were disease related, 3 were treatment related, and 1 was from a second cancer), as did 20 in the chemotherapy group (17 deaths disease related, and 3 treatment related); HR, 0.36; 95% CI, 0.16-0.82.

The incidence of acute adverse events of grade 4 or higher after prephase treatment was 33.3% in the rituximab-chemotherapy group and 24.2% in the chemotherapy group, a nonsignificant difference (P = .07). However, around twice as many patients in the rituximab-chemotherapy group had a low IgG level at 1 year after trial inclusion, compared with the chemotherapy-alone group, which could indicate the potential for more frequent infections in the long term, the researchers stated.

“An assessment of the long-term effects of combining rituximab with this chemotherapy regimen in children with non-Hodgkin lymphoma, including data on immune status, will be useful,” they added.

The study was funded by the French Ministry of Health, Cancer Research UK, the National Institute for Health Research Clinical Research Network, the Children’s Cancer Foundation Hong Kong, the U.S. National Cancer Institute, and F. Hoffmann–La Roche–Genentech. Several of the authors reported consulting for and institutional and grant funding from F. Hoffmann-LaRoche, which markets rituximab, as well as relationships with other pharmaceutical companies.

[email protected]

SOURCE: Minard-Colin V et al. N Engl J Med. 2020;382:2207-19.

The addition of rituximab to standard chemotherapy was a more effective therapy in children and adolescents with high-risk, high-grade,mature B-cell non-Hodgkin lymphoma than the use of chemotherapy alone, according to a study published in the New England Journal of Medicine. The addition of rituximab resulted in long-term complete remission in the vast majority of patients, reported Veronique Minard-Colin, MD, of the Gustave Roussy Institute, Villejuif Cedex, France, and her colleagues on behalf of the European Intergroup for Childhood Non-Hodgkin Lymphoma and the Children’s Oncology Group.

Courtesy Wikimedia Commons/Ed Uthman, MD/Creative Commons License

The researchers performed an open-label, randomized, phase 3 trial of 328 patients younger than 18 years of age with high-risk, mature B-cell non-Hodgkin’s lymphoma (stage III with an elevated lactate dehydrogenase level or stage IV) or acute leukemia to compare the addition of six doses of rituximab to standard lymphomes malins B (LMB) chemotherapy with standard LMB chemotherapy alone. There were 164 patients assigned to each group. The primary end point of the study was event-free survival; overall survival and toxic effects were also followed.

The majority of patients had Burkitt’s lymphoma: 139 (84.8%) in the rituximab-chemotherapy group and 142 (86.6%) in the chemotherapy-alone group, with diffuse large B-cell lymphoma being the second most common cancer: 19 (11.6%) vs. 12 (7.3%), respectively.

Event-free survival at 3 years was 93.9% (95% confidence interval, 89.1-96.7) in the rituximab-chemotherapy group and 82.3% (95% CI, 75.7-87.5) in the chemotherapy group.

Higher 3-year overall survival was also observed (95.1% in the rituximab-chemotherapy group vs. 87.3% in the chemotherapy group; hazard ratio for death, 0.36; 95% CI, 0.16 -0.82).

Eight patients in the rituximab-chemotherapy group died (4 deaths were disease related, 3 were treatment related, and 1 was from a second cancer), as did 20 in the chemotherapy group (17 deaths disease related, and 3 treatment related); HR, 0.36; 95% CI, 0.16-0.82.

The incidence of acute adverse events of grade 4 or higher after prephase treatment was 33.3% in the rituximab-chemotherapy group and 24.2% in the chemotherapy group, a nonsignificant difference (P = .07). However, around twice as many patients in the rituximab-chemotherapy group had a low IgG level at 1 year after trial inclusion, compared with the chemotherapy-alone group, which could indicate the potential for more frequent infections in the long term, the researchers stated.

“An assessment of the long-term effects of combining rituximab with this chemotherapy regimen in children with non-Hodgkin lymphoma, including data on immune status, will be useful,” they added.

The study was funded by the French Ministry of Health, Cancer Research UK, the National Institute for Health Research Clinical Research Network, the Children’s Cancer Foundation Hong Kong, the U.S. National Cancer Institute, and F. Hoffmann–La Roche–Genentech. Several of the authors reported consulting for and institutional and grant funding from F. Hoffmann-LaRoche, which markets rituximab, as well as relationships with other pharmaceutical companies.

[email protected]

SOURCE: Minard-Colin V et al. N Engl J Med. 2020;382:2207-19.

The World Health Organization defines malnutrition as deficiencies, excesses, or imbalances in an individual’s intake of energy and/or nutrients.¹ This review will focus on undernutrition, which may result from macronutrient or micronutrient deficiencies. Undernutrition in the hospitalized patient is a common yet underrecognized phenomenon, with an estimated prevalence of 20% to 50% worldwide.² Malnutrition is an independent risk factor for patient morbidity and mortality and has been associated with increased health care costs.³ Nutritional deficiencies may arise from inadequate nutrient intake, abnormal nutrient absorption, or improper nutrient utilization.⁴ Unfortunately, no standardized algorithm for screening and diagnosing patients with malnutrition exists, making early physical examination findings of utmost importance. Herein, we present a review of acquired nutritional deficiency dermatoses in the inpatient setting.

Protein-Energy Malnutrition

Protein-energy malnutrition (PEM) refers to a set of related disorders that include marasmus, kwashiorkor (KW), and marasmic KW. These conditions frequently are seen in developing countries but also have been reported in developed nations.⁵ Marasmus occurs from a chronic deficiency of protein and calories. Decreased insulin production and unopposed catabolism result in sarcopenia and loss of bone and subcutaneous fat.⁶ Affected patients include children who are less than 60% ideal body weight (IBW) without edema or hypoproteinemia.⁷ Kwashiorkor is the edematous form of PEM that develops from isolated protein deficiency, resulting in edema, diarrhea, and immunosuppression.⁶ Micronutrient deficiencies, oxidative stress, slow protein catabolism, and excess antidiuretic hormone have been proposed as potential drivers of KW.⁸ Kwashiorkor affects children between 60% and 80% IBW. Marasmic KW has features of both diseases, including children who are less than 60% IBW but with associated edema and/or hypoproteinemia.⁹

Although PEM is uncommon in adults, hospitalized patients carry many predisposing risk factors, including infections, malabsorptive conditions, psychiatric disease, and chronic illness (eTable). Patients with chronic infections present with findings consistent with marasmic KW due to lean body mass loss.

Zinc Deficiency

Zinc is an essential trace element that provides regulatory, structural, and catalytic functions across multiple biochemical pathways⁶ and serves as an enzymatic cofactor and key component for numerous transcription factors.¹⁷ Zinc is derived from food sources, and its concentration correlates with protein content.¹⁸ Zinc is found in both animal and plant-based proteins, albeit with a lower oral bioavailability in the latter. Zinc deficiency may be inherited or acquired. Primary acrodermatitis enteropathica is an autosomal-recessive disorder of the solute carrier family 39 member 4 gene, SLC39A4 (encodes zinc transporter ZIP4 on enterocytes); the result is abnormal zinc absorption from the small intestine.¹⁸

Acquired zinc deficiency occurs from decreased dietary zinc intake, impaired intestinal zinc absorption, excessive zinc elimination, or systemic states of high catabolism or low albumin (eTable). Total parenteral nutrition–associated deficiency has arisen when nutritional formulations did not contain trace elements during national shortages or when prolonged TPN was not anticipated and trace elements were removed.¹⁹ Zinc levels may already be low in patients with chronic illness or inflammation, so even a short period on TPN can precipitate deficiency.^18,19 Diets high in phytate may result in zinc deficiency, as phytate impairs intestinal zinc absorption.²⁰ Approximately 15% of patients with inflammatory bowel disease experienced zinc deficiency worldwide.²¹ In Crohn disease, zinc deficiency has been associated with active intestinal inflammation, increased risk for hospitalization, surgeries, and disease-related complications.^22,23

Medications such as antiepileptics, antimetabolites, or penicillamine may induce zinc deficiency, highlighting the importance of medication review for hospitalized patients (eTable). Catabolic states, frequently encountered in hospitalized patients, increase the risk for zinc deficiency.²⁴ Patients with necrolytic migratory erythema (associated with pancreatic glucagonomas) often experience low serum zinc levels.²⁵

The skin is the third most zinc-abundant tissue in the human body. Within keratinocytes, zinc is critical to normal proliferation and suppression of inflammation.¹⁷ Zinc also plays an important role in cutaneous immune function.²⁶ Zinc deficiency presents with sharply demarcated, flaccid pustules and bullae that erode into scaly, pink, eczematous or psoriasiform plaques. Lesions are found preferentially in acral and periorificial sites, often with crusting and exudate. The groin and flexural surfaces may be affected. Erosions often become secondarily impetiginized. Other cutaneous findings include angular cheilitis, stomatitis, glossitis, paronychia, onychodystrophy, generalized alopecia, and delayed wound healing.²⁶ Histopathology of skin lesions is characterized by granular layer loss, epidermal pallor, confluent parakeratosis, spongiosis, dyskeratosis, and psoriasiform hyperplasia.²⁷ Acquired bullous acrodermatitis enteropathica has been reported as a histologic mimicker of pemphigus foliaceous in patients on TPN.²⁸

Diagnosis of zinc deficiency is made by measuring plasma zinc levels. Fasting levels should be drawn in the morning, as they can fluctuate based on the time of day, stress levels, or inflammation.⁶ Sample hemolysis and anticoagulants high in zinc may falsely elevate plasma zinc. A normal zinc level is greater than 70 µg/dL; however, normal levels do not rule out deficiency.¹⁸ Measurement of zinc-dependent enzymes, such as alkaline phosphatase, can be a quick way to assess zinc status. Serum albumin also should be measured; because zinc is carried by albumin in the blood, hypoalbuminemia may result in secondary zinc deficiency.¹⁸

Zinc replacement therapy is largely through oral supplementation and should start at 0.5 to 2.0 mg/kg/d in adults with acquired disease.^29,30 Zinc sulfate is the most affordable and is the supplement of choice, with 50 mg of elemental zinc per 220 mg of zinc sulfate (~23% elemental zinc).³¹ Alternative zinc salts, such as zinc gluconate (13% elemental zinc), may be used. Patients with malabsorptive disorders often require parenteral supplementation.³² Clinical symptoms often will resolve within 1 to 2 weeks of supplementation.²⁹ In patients with primary acrodermatitis enteropathica, lifelong supplementation with 3 mg/kg/d elemental zinc should occur.⁶ Calcium and folate may reduce zinc absorption, while zinc supplementation can interfere with copper and iron absorption.³³

Iron Deficiency

Iron is an essential component of the hemoglobin molecule. Iron homeostasis and metabolism are tightly regulated processes that drive erythropoiesis. Only 5% to 10% of dietary iron is absorbed through nutrition, while the remainder is recycled from red cell breakdown. Both normal iron levels and iron deficiency (ID) are defined by age and gender.³⁴ Iron-deficiency anemia (IDA) is one of the most common cause-specific anemias worldwide.³⁵

Fatigue is the most common and earliest symptom of ID. In a single study, pallor was predictive of anemia in hospitalized patients; however, absence of pallor did not rule out anemia.³⁴ Dyspnea on exertion, tachycardia, dysphagia, and pica also may be reported. Cutaneous manifestations include koilonychia (Figure 2), glossitis, pruritus, angular cheilitis, and telogen effluvium. Plummer-Vinson syndrome is characterized by microcytic anemia, glossitis, and dysphagia.

Iron deficiency can be present despite a normal hemoglobin level. Serum ferritin and percentage transferrin saturation are key to early identification of IDA.³⁵ Ferritin levels lower than 30 µg/L confirm the diagnosis. Decreased transferrin saturation and increased total iron binding capacity aid in the diagnosis of IDA. Serum ferritin is an acute-phase reactant, and levels may be falsely elevated in the setting of inflammation or infection.

Essential Fatty Acid Deficiency

Essential fatty acids (EFAs) including linoleic and α-linolenic acid cannot be synthesized by the human body and must be obtained through diet (mostly plant oils). Essential fatty acids have various functions, including maintaining phospholipid membrane integrity, forming prostaglandins and leukotrienes, and storing energy.⁴⁰ Essential fatty acids are important in the structure and function of the stratum corneum and are crucial in maintaining epidermal barrier function.⁴¹ Increased epidermal permeability and transepidermal water loss may be the first signs of EFA deficiency (EFAD).⁴²

The cutaneous manifestations of EFAD include xerosis, weeping eczematous plaques, and erosions in intertriginous sites. The lesions may progress to widespread desquamation and erythema. With time, the skin can become thick and leathery. Alopecia may occur, and hair may depigment.⁷ Additional findings include poor wound healing and increased susceptibility to infections.^43,44

Essential fatty acid deficiency may occur when dietary fat intake is severely restricted or in malabsorptive states.^45,46 It develops in patients on prolonged TPN, typically when receiving fat-restricted nutrition,^47,48 as occurs in hypertriglyceridemia.⁴⁷ Essential fatty acid deficiency has developed in patients on TPN containing EFAs,⁴⁷ as the introduction of novel intravenous lipid emulsions has resulted in varying proportions of EFA.⁴⁰ Premature neonates are particularly at risk for EFAD.⁴⁹

The diagnosis of EFAD involves the measurement of the triene to tetraene ratio. A ratio of more than 0.2 suggests EFAD, but the clinical signs are not seen until the ratio is over 0.4.⁴⁰ Low plasma levels of linoleic, linolenic, and arachidonic acids also are seen. Elevated liver function tests are supportive of the diagnosis. Biochemical findings typically are seen before cutaneous manifestations.⁴⁰

Treatment of EFAD includes topical, oral, or intravenous replacement of EFAs. Improvement of EFAD with the application of topical linoleic acid to the skin has been reported.⁵⁰ Patients receiving TPN should undergo assessment of parenteral lipid emulsion to ensure adequate fatty acid composition.

Vitamin A Deficiency

Vitamin A (retinol) is a fat-soluble vitamin that plays a critical role in keratinization, epithelial proliferation, and cellular differentiation.⁶ Vitamin A is found in animal products as retinyl esters and in plants as beta-carotene. Vitamin A has 2 clinically important forms: all-trans retinoic acid and 11-cis-retinal. All-trans retinoic acid is involved in cellular differentiation and regulating gene transcription, while 11-cis-retinal is key to rhodopsin generation required for vision. Vitamin A deficiency presents with early ophthalmologic findings, specifically nyctalopia, or delayed adaptation to the dark.⁵¹ Xerophthalmia, abnormal conjunctival keratinization, and Bitot spots subsequently develop and may progress to corneal ulceration and blindness.⁶

Vitamin A deficiency manifests in the skin as follicular hyperkeratosis, or phrynoderma. Notably, numerous other micronutrient deficiencies may result in phrynoderma. Clinically, multiple pigmented keratotic papules of various sizes, many with a central keratinous plug, are distributed symmetrically on the extensor elbows, knees, shoulders, buttocks, and extremities. The skin surrounding these lesions may be scaly and hyperpigmented.⁵² Generalized xerosis without preceding nyctalopia has been reported.⁵³ Accompanying pityriasis alba may develop.⁵² Lesions on the face may mimic acne, while lesions on the extremities may simulate a perforating disorder. Histopathology of phrynoderma reveals epidermal hyperkeratosis, follicular hyperkeratosis, and follicular plugging.⁵²

Vitamin A deficiency can be diagnosed by measuring serum retinol levels, with levels lower than 20 µg/dL being diagnostic of deficiency.⁵⁶ Decreased serum retinol in patients hospitalized with flaring irritable bowel disorder has been repeatedly reported.^57-59 Notably, serum retinol concentration does not decline until liver reserves of vitamin A are nearing exhaustion.³³

The US Food and Drug Administration requires manufacturers to list retinol activity equivalents on labels. One international unit of retinol is equivalent to 0.3 µg of retinol activity equivalents.⁶⁰ The treatment of vitamin A deficiency involves high-dose oral supplementation when possible.⁶¹ Although dependent on age, the treatment dose for most adults with vitamin A deficiency is 3000 µg (10,000 IU) once daily.

Phrynoderma has been specifically treated with salicylic acid ointment 3% and intramuscular vitamin A.⁶² Topical urea cream also may treat phrynoderma.⁶³

Vitamin B₂

Vitamin B₂ (riboflavin) is absorbed in the small intestine and converted into 2 biologically active forms—flavin adenine dinucleotide and flavin mononucleotide—which serve as cofactors in metabolic and oxidation-reduction reactions. Malabsorptive disorders and bowel resection can lead to riboflavin deficiency.⁶⁴ Other at-risk populations include those with restrictive diets,⁶⁵ psychiatric illness, or systemic illness (eTable). Riboflavin can be degraded by light (deficiency has been reported after phototherapy for neonatal jaundice⁶⁶) and following boric acid ingestion.⁶⁷ Medications, including long-term treatment with antiepileptics, may lead to riboflavin deficiency.⁶⁸

Riboflavin is critical to maintaining collagen production. Riboflavin deficiency may manifest clinically with extensive seborrheiclike dermatitis,⁴⁴ intertrigolike dermatitis,⁶⁹ or oral-ocular-genital syndrome.⁷⁰ Angular cheilitis may accompany an atrophic tongue that is deep red in color. The scrotum is characteristically involved in men, with confluent dermatitis extending onto the thighs and sparing the midline. Red papules and painful fissures may develop. Balanitis and phimosis have been reported. Testing for riboflavin deficiency should be considered in patients with refractory seborrheic dermatitis.

Riboflavin stores are assessed by the erythrocyte glutathione reductase activity coefficient.⁴⁴ A level of 1.4 or higher is consistent with deficiency. Serum riboflavin levels, performed after a 12-hour fast, may support the diagnosis but are less sensitive. Patients with glucose-6-phosphate deficiency cannot be assessed via the erythrocyte glutathione reductase activity coefficient and may instead require evaluation of 24-hour urine riboflavin level.⁴⁴

Vitamin B₃

Vitamin B₃ (niacin, nicotinamide, nicotinic acid) is found in plant and animal products or can be derived from its amino acid precursor tryptophan. Niacin deficiency results in pellagra, characterized by dermatitis, dementia, and diarrhea.⁷¹ The most prominent feature is a symmetrically distributed photosensitive dermatitis of the face, neck (called Casal necklace)(Figure 3), chest, dorsal hands, and extensor arms. The eruption may begin with erythema, vesicles, or bullae (wet pellagra) and evolve into thick, hyperpigmented, scaling plaques.⁷¹ The skin may take on a copper tone and become atrophic.⁷² Dull erythema with overlying yellow powdery scale (called sulfur flakes) at follicular orifices has been described on the nasal bridge.⁷³

Causes of niacin deficiency include malabsorptive conditions, malignancy (including carcinoid tumors), parenteral nutrition, psychiatric disease,^74,75 and restrictive diets (eTable).⁷⁶ Carcinoid tumors divert tryptophan to serotonin resulting in niacin deficiency.⁷⁷

The diagnosis of niacin deficiency is based on clinical findings and response to supplementation.⁷⁵ Low niacin urinary metabolites (N-methylnicotinamide and 2-pyridone) may aid in diagnosis.⁶ Treatment generally includes oral nicotinamide 100 mg every 6 hours; the dose can then be tapered to 50 mg every 8 to 12 hours until symptoms resolve. Severe deficiency may require parenteral nicotinamide 1 g 3 to 4 times daily.⁷⁵

Vitamin B₆

Vitamin B₆ (pyridoxine, pyridoxamine, pyridoxal) is found in whole grains and plant and animal products. Vitamin B₆ functions as a coenzyme in many metabolic pathways and is involved in the conversion of tryptophan to niacin.⁴⁴ Absorption requires hydrolysis by intestinal phosphates and transport to the liver for rephosphorylation prior to release in active form.⁶

Cutaneous findings associated with vitamin B₆ deficiency include periorificial and perineal seborrheic dermatitis,⁷⁸ angular stomatitis, and cheilitis, with associated burning, redness, and tongue edema.⁶ Vitamin B₆ deficiency is a rarely reported cause of burning mouth syndrome.⁷⁹ Because vitamin B₆ is involved in the conversion of tryptophan to niacin, deficiency also may present with pellagralike findings.⁷⁰ Other clinical symptoms are outlined in the eTable.^80,81

Conditions that increase risk for vitamin B₆ deficiency are highlighted in the eTable and include malabsorptive disorders; psychiatric illness⁸²; and chronic disease, especially end-stage renal disease.⁸³ Vitamin B₆ deficiency associated with chronic alcohol use is due to both inadequate vitamin B₆ intake as well as reduced hepatic storage.⁷⁸ Medications such as isoniazid, hydralazine, and oral contraceptives may decrease vitamin B₆ levels (eTable).⁸²

Vitamin B₆ can be measured in the plasma as pyridoxal 5′-phosphate. Plasma concentrations of less than 20 nmol/L are suggestive of deficiency.⁸² Indirect tests include tryptophan and methionine loading.⁶ The treatment of vitamin B₆ deficiency is determined by symptom severity. Recommendations for oral supplementation range from 25 to 600 mg daily.⁸² Symptoms typically improve on 100 mg daily.⁶

Vitamins B₉ and B₁₂

Deficiencies of vitamins B₉ (folic acid, folate) and B₁₂ (cobalamin) have similar clinical presentations. Folate is essential in the metabolism of amino acids, purines, and pyrimidines.⁶ Cobalamin, found in animal products, is a cofactor for methionine synthase and methylmalonyl-CoA mutase.⁸⁴ Megaloblastic anemia is the main finding in folate or cobalamin deficiency. Neurologic findings only accompany cobalamin deficiency. Risk factors for folate deficiency include malabsorptive conditions,⁶ chronic alcohol use,⁸⁵ and antifolate medication use (eTable).⁶

Cobalamin absorption requires gastric acid and intrinsic factor binding in the duodenum. Deficiency may occur from strict diets, psychiatric illness, old age,⁸⁶ decreased gastric acid secretion,⁸⁷ abnormal intrinsic factor function, or intestinal infections.⁶

Generalized cutaneous hyperpigmentation may be the first manifestation of vitamins B₉ and B₁₂ deficiency.⁸⁸ Typically accentuated in acral creases and the oral cavity, pigmentation may mimic Addison disease. Hair depigmentation and linear streaking of the nails are reported.⁸⁴ The tongue becomes painful and red with atrophy of the filiform papillae (Hunter glossitis).⁷⁸ Linear lesions on the tongue and hard palate may serve as an early sign of cobalamin deficiency.⁸⁹

Folate deficiency is diagnosed by measuring the plasma folate level; coincidental cobalamin deficiency should be excluded. Deficiency is managed with oral supplementation (when possible) with 1 to 5 mg of folate daily.⁶ Cobalamin deficiency is based on low serum levels (<150 pg/mL is diagnostic).⁸⁶ Cobalamin deficiency may take years to develop, as vitamin B₁₂ exists in large body stores.⁶ Serum methylmalonic acid may be elevated in patients with clinical features but normal-low serum vitamin B₁₂ level.⁸⁶ Treatment of vitamin B₁₂ deficiency is with oral (2 mg once daily) or parenteral (1 mg every 4 weeks then maintained at once monthly) cyanocobalamin. For patients with neurologic symptoms, intramuscular injection should be given.⁸⁶ The underlying cause of deficiency must be elucidated and treated.

Vitamin C Deficiency

Vitamin C (ascorbic acid) is an essential cofactor for the hydroxylation of proline and lysine residues in collagen synthesis. Plant-based foods are the main dietary source of vitamin C, and deficiency presents clinically as scurvy. Cutaneous findings include follicular hyperkeratosis, perifollicular petechiae, and curled hair shafts (corkscrew hairs)(Figure 4). Ecchymoses of the lower extremities, forearms, and abdomen may be seen. Nodules representing intramuscular and subcutaneous hemorrhage can be present.⁹⁰ Woody edema may mimic cellulitis, while lower extremity hemorrhage may mimic vasculitis. Gingival hyperplasia, hemorrhage, and edema may occur,⁹⁰ along with linear splinter hemorrhages.⁹¹

Hypovitaminosis C has been routinely demonstrated in hospitalized patients.⁹² Scurvy may occur in patients on strict diets,⁹³ chronic alcohol use,⁹⁴ psychiatric illness,⁹⁵ or gastrointestinal tract disease (eTable).^96-99 Those with low socioeconomic status⁷⁰ or dementia¹⁰⁰ as well as the elderly also are at risk.¹⁰¹ Scurvy has developed in patients with iron overload and those who are on hemodialysis⁴⁴ as well as in association with nilotinib use.¹⁰² Patients with chronic mucous membrane graft-vs-host disease may exhibit vitamin C deficiency.¹⁰³

Scurvy is a clinical diagnosis. Vitamin C levels normalize quickly with supplementation. Cutaneous biopsy will exhibit follicular hyperkeratosis, perifollicular hemorrhage, and fibrosis.⁹¹

Oral ascorbic acid supplementation should be initiated at 500 to 1000 mg daily in adults.¹⁰⁴ The cause of deficiency should be identified, and further supplementation should be decided based on patient risk factors. Lifestyle modifications, such as cessation of smoking and chronic alcohol use, is recommended. The diagnosis of scurvy should prompt workup for additional nutrient deficiencies.

Final Thoughts

Dermatologists play an important role in the early recognition of nutritional deficiencies, as cutaneous manifestations often are the first clue to diagnosis. Nutritional deficiencies are common yet underrecognized in the hospitalized patient and serve as an independent risk factor for patient morbidity and mortality.³ Awareness of the cutaneous manifestations of undernutrition as well as the risk factors for nutritional deficiency may expedite diagnosis and supplementation, thereby improving outcomes for hospitalized patients.

The World Health Organization defines malnutrition as deficiencies, excesses, or imbalances in an individual’s intake of energy and/or nutrients.¹ This review will focus on undernutrition, which may result from macronutrient or micronutrient deficiencies. Undernutrition in the hospitalized patient is a common yet underrecognized phenomenon, with an estimated prevalence of 20% to 50% worldwide.² Malnutrition is an independent risk factor for patient morbidity and mortality and has been associated with increased health care costs.³ Nutritional deficiencies may arise from inadequate nutrient intake, abnormal nutrient absorption, or improper nutrient utilization.⁴ Unfortunately, no standardized algorithm for screening and diagnosing patients with malnutrition exists, making early physical examination findings of utmost importance. Herein, we present a review of acquired nutritional deficiency dermatoses in the inpatient setting.

Protein-Energy Malnutrition

Protein-energy malnutrition (PEM) refers to a set of related disorders that include marasmus, kwashiorkor (KW), and marasmic KW. These conditions frequently are seen in developing countries but also have been reported in developed nations.⁵ Marasmus occurs from a chronic deficiency of protein and calories. Decreased insulin production and unopposed catabolism result in sarcopenia and loss of bone and subcutaneous fat.⁶ Affected patients include children who are less than 60% ideal body weight (IBW) without edema or hypoproteinemia.⁷ Kwashiorkor is the edematous form of PEM that develops from isolated protein deficiency, resulting in edema, diarrhea, and immunosuppression.⁶ Micronutrient deficiencies, oxidative stress, slow protein catabolism, and excess antidiuretic hormone have been proposed as potential drivers of KW.⁸ Kwashiorkor affects children between 60% and 80% IBW. Marasmic KW has features of both diseases, including children who are less than 60% IBW but with associated edema and/or hypoproteinemia.⁹

Although PEM is uncommon in adults, hospitalized patients carry many predisposing risk factors, including infections, malabsorptive conditions, psychiatric disease, and chronic illness (eTable). Patients with chronic infections present with findings consistent with marasmic KW due to lean body mass loss.

Zinc Deficiency

Zinc is an essential trace element that provides regulatory, structural, and catalytic functions across multiple biochemical pathways⁶ and serves as an enzymatic cofactor and key component for numerous transcription factors.¹⁷ Zinc is derived from food sources, and its concentration correlates with protein content.¹⁸ Zinc is found in both animal and plant-based proteins, albeit with a lower oral bioavailability in the latter. Zinc deficiency may be inherited or acquired. Primary acrodermatitis enteropathica is an autosomal-recessive disorder of the solute carrier family 39 member 4 gene, SLC39A4 (encodes zinc transporter ZIP4 on enterocytes); the result is abnormal zinc absorption from the small intestine.¹⁸

Acquired zinc deficiency occurs from decreased dietary zinc intake, impaired intestinal zinc absorption, excessive zinc elimination, or systemic states of high catabolism or low albumin (eTable). Total parenteral nutrition–associated deficiency has arisen when nutritional formulations did not contain trace elements during national shortages or when prolonged TPN was not anticipated and trace elements were removed.¹⁹ Zinc levels may already be low in patients with chronic illness or inflammation, so even a short period on TPN can precipitate deficiency.^18,19 Diets high in phytate may result in zinc deficiency, as phytate impairs intestinal zinc absorption.²⁰ Approximately 15% of patients with inflammatory bowel disease experienced zinc deficiency worldwide.²¹ In Crohn disease, zinc deficiency has been associated with active intestinal inflammation, increased risk for hospitalization, surgeries, and disease-related complications.^22,23

Medications such as antiepileptics, antimetabolites, or penicillamine may induce zinc deficiency, highlighting the importance of medication review for hospitalized patients (eTable). Catabolic states, frequently encountered in hospitalized patients, increase the risk for zinc deficiency.²⁴ Patients with necrolytic migratory erythema (associated with pancreatic glucagonomas) often experience low serum zinc levels.²⁵

The skin is the third most zinc-abundant tissue in the human body. Within keratinocytes, zinc is critical to normal proliferation and suppression of inflammation.¹⁷ Zinc also plays an important role in cutaneous immune function.²⁶ Zinc deficiency presents with sharply demarcated, flaccid pustules and bullae that erode into scaly, pink, eczematous or psoriasiform plaques. Lesions are found preferentially in acral and periorificial sites, often with crusting and exudate. The groin and flexural surfaces may be affected. Erosions often become secondarily impetiginized. Other cutaneous findings include angular cheilitis, stomatitis, glossitis, paronychia, onychodystrophy, generalized alopecia, and delayed wound healing.²⁶ Histopathology of skin lesions is characterized by granular layer loss, epidermal pallor, confluent parakeratosis, spongiosis, dyskeratosis, and psoriasiform hyperplasia.²⁷ Acquired bullous acrodermatitis enteropathica has been reported as a histologic mimicker of pemphigus foliaceous in patients on TPN.²⁸

Diagnosis of zinc deficiency is made by measuring plasma zinc levels. Fasting levels should be drawn in the morning, as they can fluctuate based on the time of day, stress levels, or inflammation.⁶ Sample hemolysis and anticoagulants high in zinc may falsely elevate plasma zinc. A normal zinc level is greater than 70 µg/dL; however, normal levels do not rule out deficiency.¹⁸ Measurement of zinc-dependent enzymes, such as alkaline phosphatase, can be a quick way to assess zinc status. Serum albumin also should be measured; because zinc is carried by albumin in the blood, hypoalbuminemia may result in secondary zinc deficiency.¹⁸

Zinc replacement therapy is largely through oral supplementation and should start at 0.5 to 2.0 mg/kg/d in adults with acquired disease.^29,30 Zinc sulfate is the most affordable and is the supplement of choice, with 50 mg of elemental zinc per 220 mg of zinc sulfate (~23% elemental zinc).³¹ Alternative zinc salts, such as zinc gluconate (13% elemental zinc), may be used. Patients with malabsorptive disorders often require parenteral supplementation.³² Clinical symptoms often will resolve within 1 to 2 weeks of supplementation.²⁹ In patients with primary acrodermatitis enteropathica, lifelong supplementation with 3 mg/kg/d elemental zinc should occur.⁶ Calcium and folate may reduce zinc absorption, while zinc supplementation can interfere with copper and iron absorption.³³

Iron Deficiency

Iron is an essential component of the hemoglobin molecule. Iron homeostasis and metabolism are tightly regulated processes that drive erythropoiesis. Only 5% to 10% of dietary iron is absorbed through nutrition, while the remainder is recycled from red cell breakdown. Both normal iron levels and iron deficiency (ID) are defined by age and gender.³⁴ Iron-deficiency anemia (IDA) is one of the most common cause-specific anemias worldwide.³⁵

Fatigue is the most common and earliest symptom of ID. In a single study, pallor was predictive of anemia in hospitalized patients; however, absence of pallor did not rule out anemia.³⁴ Dyspnea on exertion, tachycardia, dysphagia, and pica also may be reported. Cutaneous manifestations include koilonychia (Figure 2), glossitis, pruritus, angular cheilitis, and telogen effluvium. Plummer-Vinson syndrome is characterized by microcytic anemia, glossitis, and dysphagia.

Iron deficiency can be present despite a normal hemoglobin level. Serum ferritin and percentage transferrin saturation are key to early identification of IDA.³⁵ Ferritin levels lower than 30 µg/L confirm the diagnosis. Decreased transferrin saturation and increased total iron binding capacity aid in the diagnosis of IDA. Serum ferritin is an acute-phase reactant, and levels may be falsely elevated in the setting of inflammation or infection.

Essential Fatty Acid Deficiency

Essential fatty acids (EFAs) including linoleic and α-linolenic acid cannot be synthesized by the human body and must be obtained through diet (mostly plant oils). Essential fatty acids have various functions, including maintaining phospholipid membrane integrity, forming prostaglandins and leukotrienes, and storing energy.⁴⁰ Essential fatty acids are important in the structure and function of the stratum corneum and are crucial in maintaining epidermal barrier function.⁴¹ Increased epidermal permeability and transepidermal water loss may be the first signs of EFA deficiency (EFAD).⁴²

The cutaneous manifestations of EFAD include xerosis, weeping eczematous plaques, and erosions in intertriginous sites. The lesions may progress to widespread desquamation and erythema. With time, the skin can become thick and leathery. Alopecia may occur, and hair may depigment.⁷ Additional findings include poor wound healing and increased susceptibility to infections.^43,44

Essential fatty acid deficiency may occur when dietary fat intake is severely restricted or in malabsorptive states.^45,46 It develops in patients on prolonged TPN, typically when receiving fat-restricted nutrition,^47,48 as occurs in hypertriglyceridemia.⁴⁷ Essential fatty acid deficiency has developed in patients on TPN containing EFAs,⁴⁷ as the introduction of novel intravenous lipid emulsions has resulted in varying proportions of EFA.⁴⁰ Premature neonates are particularly at risk for EFAD.⁴⁹

The diagnosis of EFAD involves the measurement of the triene to tetraene ratio. A ratio of more than 0.2 suggests EFAD, but the clinical signs are not seen until the ratio is over 0.4.⁴⁰ Low plasma levels of linoleic, linolenic, and arachidonic acids also are seen. Elevated liver function tests are supportive of the diagnosis. Biochemical findings typically are seen before cutaneous manifestations.⁴⁰

Treatment of EFAD includes topical, oral, or intravenous replacement of EFAs. Improvement of EFAD with the application of topical linoleic acid to the skin has been reported.⁵⁰ Patients receiving TPN should undergo assessment of parenteral lipid emulsion to ensure adequate fatty acid composition.

Vitamin A Deficiency

Vitamin A (retinol) is a fat-soluble vitamin that plays a critical role in keratinization, epithelial proliferation, and cellular differentiation.⁶ Vitamin A is found in animal products as retinyl esters and in plants as beta-carotene. Vitamin A has 2 clinically important forms: all-trans retinoic acid and 11-cis-retinal. All-trans retinoic acid is involved in cellular differentiation and regulating gene transcription, while 11-cis-retinal is key to rhodopsin generation required for vision. Vitamin A deficiency presents with early ophthalmologic findings, specifically nyctalopia, or delayed adaptation to the dark.⁵¹ Xerophthalmia, abnormal conjunctival keratinization, and Bitot spots subsequently develop and may progress to corneal ulceration and blindness.⁶

Vitamin A deficiency manifests in the skin as follicular hyperkeratosis, or phrynoderma. Notably, numerous other micronutrient deficiencies may result in phrynoderma. Clinically, multiple pigmented keratotic papules of various sizes, many with a central keratinous plug, are distributed symmetrically on the extensor elbows, knees, shoulders, buttocks, and extremities. The skin surrounding these lesions may be scaly and hyperpigmented.⁵² Generalized xerosis without preceding nyctalopia has been reported.⁵³ Accompanying pityriasis alba may develop.⁵² Lesions on the face may mimic acne, while lesions on the extremities may simulate a perforating disorder. Histopathology of phrynoderma reveals epidermal hyperkeratosis, follicular hyperkeratosis, and follicular plugging.⁵²

Vitamin A deficiency can be diagnosed by measuring serum retinol levels, with levels lower than 20 µg/dL being diagnostic of deficiency.⁵⁶ Decreased serum retinol in patients hospitalized with flaring irritable bowel disorder has been repeatedly reported.^57-59 Notably, serum retinol concentration does not decline until liver reserves of vitamin A are nearing exhaustion.³³

The US Food and Drug Administration requires manufacturers to list retinol activity equivalents on labels. One international unit of retinol is equivalent to 0.3 µg of retinol activity equivalents.⁶⁰ The treatment of vitamin A deficiency involves high-dose oral supplementation when possible.⁶¹ Although dependent on age, the treatment dose for most adults with vitamin A deficiency is 3000 µg (10,000 IU) once daily.

Phrynoderma has been specifically treated with salicylic acid ointment 3% and intramuscular vitamin A.⁶² Topical urea cream also may treat phrynoderma.⁶³

Vitamin B₂

Vitamin B₂ (riboflavin) is absorbed in the small intestine and converted into 2 biologically active forms—flavin adenine dinucleotide and flavin mononucleotide—which serve as cofactors in metabolic and oxidation-reduction reactions. Malabsorptive disorders and bowel resection can lead to riboflavin deficiency.⁶⁴ Other at-risk populations include those with restrictive diets,⁶⁵ psychiatric illness, or systemic illness (eTable). Riboflavin can be degraded by light (deficiency has been reported after phototherapy for neonatal jaundice⁶⁶) and following boric acid ingestion.⁶⁷ Medications, including long-term treatment with antiepileptics, may lead to riboflavin deficiency.⁶⁸

Riboflavin is critical to maintaining collagen production. Riboflavin deficiency may manifest clinically with extensive seborrheiclike dermatitis,⁴⁴ intertrigolike dermatitis,⁶⁹ or oral-ocular-genital syndrome.⁷⁰ Angular cheilitis may accompany an atrophic tongue that is deep red in color. The scrotum is characteristically involved in men, with confluent dermatitis extending onto the thighs and sparing the midline. Red papules and painful fissures may develop. Balanitis and phimosis have been reported. Testing for riboflavin deficiency should be considered in patients with refractory seborrheic dermatitis.

Riboflavin stores are assessed by the erythrocyte glutathione reductase activity coefficient.⁴⁴ A level of 1.4 or higher is consistent with deficiency. Serum riboflavin levels, performed after a 12-hour fast, may support the diagnosis but are less sensitive. Patients with glucose-6-phosphate deficiency cannot be assessed via the erythrocyte glutathione reductase activity coefficient and may instead require evaluation of 24-hour urine riboflavin level.⁴⁴

Vitamin B₃

Vitamin B₃ (niacin, nicotinamide, nicotinic acid) is found in plant and animal products or can be derived from its amino acid precursor tryptophan. Niacin deficiency results in pellagra, characterized by dermatitis, dementia, and diarrhea.⁷¹ The most prominent feature is a symmetrically distributed photosensitive dermatitis of the face, neck (called Casal necklace)(Figure 3), chest, dorsal hands, and extensor arms. The eruption may begin with erythema, vesicles, or bullae (wet pellagra) and evolve into thick, hyperpigmented, scaling plaques.⁷¹ The skin may take on a copper tone and become atrophic.⁷² Dull erythema with overlying yellow powdery scale (called sulfur flakes) at follicular orifices has been described on the nasal bridge.⁷³

Causes of niacin deficiency include malabsorptive conditions, malignancy (including carcinoid tumors), parenteral nutrition, psychiatric disease,^74,75 and restrictive diets (eTable).⁷⁶ Carcinoid tumors divert tryptophan to serotonin resulting in niacin deficiency.⁷⁷

The diagnosis of niacin deficiency is based on clinical findings and response to supplementation.⁷⁵ Low niacin urinary metabolites (N-methylnicotinamide and 2-pyridone) may aid in diagnosis.⁶ Treatment generally includes oral nicotinamide 100 mg every 6 hours; the dose can then be tapered to 50 mg every 8 to 12 hours until symptoms resolve. Severe deficiency may require parenteral nicotinamide 1 g 3 to 4 times daily.⁷⁵

Vitamin B₆

Vitamin B₆ (pyridoxine, pyridoxamine, pyridoxal) is found in whole grains and plant and animal products. Vitamin B₆ functions as a coenzyme in many metabolic pathways and is involved in the conversion of tryptophan to niacin.⁴⁴ Absorption requires hydrolysis by intestinal phosphates and transport to the liver for rephosphorylation prior to release in active form.⁶

Cutaneous findings associated with vitamin B₆ deficiency include periorificial and perineal seborrheic dermatitis,⁷⁸ angular stomatitis, and cheilitis, with associated burning, redness, and tongue edema.⁶ Vitamin B₆ deficiency is a rarely reported cause of burning mouth syndrome.⁷⁹ Because vitamin B₆ is involved in the conversion of tryptophan to niacin, deficiency also may present with pellagralike findings.⁷⁰ Other clinical symptoms are outlined in the eTable.^80,81

Conditions that increase risk for vitamin B₆ deficiency are highlighted in the eTable and include malabsorptive disorders; psychiatric illness⁸²; and chronic disease, especially end-stage renal disease.⁸³ Vitamin B₆ deficiency associated with chronic alcohol use is due to both inadequate vitamin B₆ intake as well as reduced hepatic storage.⁷⁸ Medications such as isoniazid, hydralazine, and oral contraceptives may decrease vitamin B₆ levels (eTable).⁸²

Vitamin B₆ can be measured in the plasma as pyridoxal 5′-phosphate. Plasma concentrations of less than 20 nmol/L are suggestive of deficiency.⁸² Indirect tests include tryptophan and methionine loading.⁶ The treatment of vitamin B₆ deficiency is determined by symptom severity. Recommendations for oral supplementation range from 25 to 600 mg daily.⁸² Symptoms typically improve on 100 mg daily.⁶

Vitamins B₉ and B₁₂

Deficiencies of vitamins B₉ (folic acid, folate) and B₁₂ (cobalamin) have similar clinical presentations. Folate is essential in the metabolism of amino acids, purines, and pyrimidines.⁶ Cobalamin, found in animal products, is a cofactor for methionine synthase and methylmalonyl-CoA mutase.⁸⁴ Megaloblastic anemia is the main finding in folate or cobalamin deficiency. Neurologic findings only accompany cobalamin deficiency. Risk factors for folate deficiency include malabsorptive conditions,⁶ chronic alcohol use,⁸⁵ and antifolate medication use (eTable).⁶

Cobalamin absorption requires gastric acid and intrinsic factor binding in the duodenum. Deficiency may occur from strict diets, psychiatric illness, old age,⁸⁶ decreased gastric acid secretion,⁸⁷ abnormal intrinsic factor function, or intestinal infections.⁶

Generalized cutaneous hyperpigmentation may be the first manifestation of vitamins B₉ and B₁₂ deficiency.⁸⁸ Typically accentuated in acral creases and the oral cavity, pigmentation may mimic Addison disease. Hair depigmentation and linear streaking of the nails are reported.⁸⁴ The tongue becomes painful and red with atrophy of the filiform papillae (Hunter glossitis).⁷⁸ Linear lesions on the tongue and hard palate may serve as an early sign of cobalamin deficiency.⁸⁹

Folate deficiency is diagnosed by measuring the plasma folate level; coincidental cobalamin deficiency should be excluded. Deficiency is managed with oral supplementation (when possible) with 1 to 5 mg of folate daily.⁶ Cobalamin deficiency is based on low serum levels (<150 pg/mL is diagnostic).⁸⁶ Cobalamin deficiency may take years to develop, as vitamin B₁₂ exists in large body stores.⁶ Serum methylmalonic acid may be elevated in patients with clinical features but normal-low serum vitamin B₁₂ level.⁸⁶ Treatment of vitamin B₁₂ deficiency is with oral (2 mg once daily) or parenteral (1 mg every 4 weeks then maintained at once monthly) cyanocobalamin. For patients with neurologic symptoms, intramuscular injection should be given.⁸⁶ The underlying cause of deficiency must be elucidated and treated.

Vitamin C Deficiency

Vitamin C (ascorbic acid) is an essential cofactor for the hydroxylation of proline and lysine residues in collagen synthesis. Plant-based foods are the main dietary source of vitamin C, and deficiency presents clinically as scurvy. Cutaneous findings include follicular hyperkeratosis, perifollicular petechiae, and curled hair shafts (corkscrew hairs)(Figure 4). Ecchymoses of the lower extremities, forearms, and abdomen may be seen. Nodules representing intramuscular and subcutaneous hemorrhage can be present.⁹⁰ Woody edema may mimic cellulitis, while lower extremity hemorrhage may mimic vasculitis. Gingival hyperplasia, hemorrhage, and edema may occur,⁹⁰ along with linear splinter hemorrhages.⁹¹

Hypovitaminosis C has been routinely demonstrated in hospitalized patients.⁹² Scurvy may occur in patients on strict diets,⁹³ chronic alcohol use,⁹⁴ psychiatric illness,⁹⁵ or gastrointestinal tract disease (eTable).^96-99 Those with low socioeconomic status⁷⁰ or dementia¹⁰⁰ as well as the elderly also are at risk.¹⁰¹ Scurvy has developed in patients with iron overload and those who are on hemodialysis⁴⁴ as well as in association with nilotinib use.¹⁰² Patients with chronic mucous membrane graft-vs-host disease may exhibit vitamin C deficiency.¹⁰³

Scurvy is a clinical diagnosis. Vitamin C levels normalize quickly with supplementation. Cutaneous biopsy will exhibit follicular hyperkeratosis, perifollicular hemorrhage, and fibrosis.⁹¹

Oral ascorbic acid supplementation should be initiated at 500 to 1000 mg daily in adults.¹⁰⁴ The cause of deficiency should be identified, and further supplementation should be decided based on patient risk factors. Lifestyle modifications, such as cessation of smoking and chronic alcohol use, is recommended. The diagnosis of scurvy should prompt workup for additional nutrient deficiencies.

Final Thoughts

Dermatologists play an important role in the early recognition of nutritional deficiencies, as cutaneous manifestations often are the first clue to diagnosis. Nutritional deficiencies are common yet underrecognized in the hospitalized patient and serve as an independent risk factor for patient morbidity and mortality.³ Awareness of the cutaneous manifestations of undernutrition as well as the risk factors for nutritional deficiency may expedite diagnosis and supplementation, thereby improving outcomes for hospitalized patients.

The World Health Organization defines malnutrition as deficiencies, excesses, or imbalances in an individual’s intake of energy and/or nutrients.¹ This review will focus on undernutrition, which may result from macronutrient or micronutrient deficiencies. Undernutrition in the hospitalized patient is a common yet underrecognized phenomenon, with an estimated prevalence of 20% to 50% worldwide.² Malnutrition is an independent risk factor for patient morbidity and mortality and has been associated with increased health care costs.³ Nutritional deficiencies may arise from inadequate nutrient intake, abnormal nutrient absorption, or improper nutrient utilization.⁴ Unfortunately, no standardized algorithm for screening and diagnosing patients with malnutrition exists, making early physical examination findings of utmost importance. Herein, we present a review of acquired nutritional deficiency dermatoses in the inpatient setting.

Protein-Energy Malnutrition

Protein-energy malnutrition (PEM) refers to a set of related disorders that include marasmus, kwashiorkor (KW), and marasmic KW. These conditions frequently are seen in developing countries but also have been reported in developed nations.⁵ Marasmus occurs from a chronic deficiency of protein and calories. Decreased insulin production and unopposed catabolism result in sarcopenia and loss of bone and subcutaneous fat.⁶ Affected patients include children who are less than 60% ideal body weight (IBW) without edema or hypoproteinemia.⁷ Kwashiorkor is the edematous form of PEM that develops from isolated protein deficiency, resulting in edema, diarrhea, and immunosuppression.⁶ Micronutrient deficiencies, oxidative stress, slow protein catabolism, and excess antidiuretic hormone have been proposed as potential drivers of KW.⁸ Kwashiorkor affects children between 60% and 80% IBW. Marasmic KW has features of both diseases, including children who are less than 60% IBW but with associated edema and/or hypoproteinemia.⁹

Although PEM is uncommon in adults, hospitalized patients carry many predisposing risk factors, including infections, malabsorptive conditions, psychiatric disease, and chronic illness (eTable). Patients with chronic infections present with findings consistent with marasmic KW due to lean body mass loss.

Zinc Deficiency

Zinc is an essential trace element that provides regulatory, structural, and catalytic functions across multiple biochemical pathways⁶ and serves as an enzymatic cofactor and key component for numerous transcription factors.¹⁷ Zinc is derived from food sources, and its concentration correlates with protein content.¹⁸ Zinc is found in both animal and plant-based proteins, albeit with a lower oral bioavailability in the latter. Zinc deficiency may be inherited or acquired. Primary acrodermatitis enteropathica is an autosomal-recessive disorder of the solute carrier family 39 member 4 gene, SLC39A4 (encodes zinc transporter ZIP4 on enterocytes); the result is abnormal zinc absorption from the small intestine.¹⁸

Acquired zinc deficiency occurs from decreased dietary zinc intake, impaired intestinal zinc absorption, excessive zinc elimination, or systemic states of high catabolism or low albumin (eTable). Total parenteral nutrition–associated deficiency has arisen when nutritional formulations did not contain trace elements during national shortages or when prolonged TPN was not anticipated and trace elements were removed.¹⁹ Zinc levels may already be low in patients with chronic illness or inflammation, so even a short period on TPN can precipitate deficiency.^18,19 Diets high in phytate may result in zinc deficiency, as phytate impairs intestinal zinc absorption.²⁰ Approximately 15% of patients with inflammatory bowel disease experienced zinc deficiency worldwide.²¹ In Crohn disease, zinc deficiency has been associated with active intestinal inflammation, increased risk for hospitalization, surgeries, and disease-related complications.^22,23

Medications such as antiepileptics, antimetabolites, or penicillamine may induce zinc deficiency, highlighting the importance of medication review for hospitalized patients (eTable). Catabolic states, frequently encountered in hospitalized patients, increase the risk for zinc deficiency.²⁴ Patients with necrolytic migratory erythema (associated with pancreatic glucagonomas) often experience low serum zinc levels.²⁵

The skin is the third most zinc-abundant tissue in the human body. Within keratinocytes, zinc is critical to normal proliferation and suppression of inflammation.¹⁷ Zinc also plays an important role in cutaneous immune function.²⁶ Zinc deficiency presents with sharply demarcated, flaccid pustules and bullae that erode into scaly, pink, eczematous or psoriasiform plaques. Lesions are found preferentially in acral and periorificial sites, often with crusting and exudate. The groin and flexural surfaces may be affected. Erosions often become secondarily impetiginized. Other cutaneous findings include angular cheilitis, stomatitis, glossitis, paronychia, onychodystrophy, generalized alopecia, and delayed wound healing.²⁶ Histopathology of skin lesions is characterized by granular layer loss, epidermal pallor, confluent parakeratosis, spongiosis, dyskeratosis, and psoriasiform hyperplasia.²⁷ Acquired bullous acrodermatitis enteropathica has been reported as a histologic mimicker of pemphigus foliaceous in patients on TPN.²⁸

Diagnosis of zinc deficiency is made by measuring plasma zinc levels. Fasting levels should be drawn in the morning, as they can fluctuate based on the time of day, stress levels, or inflammation.⁶ Sample hemolysis and anticoagulants high in zinc may falsely elevate plasma zinc. A normal zinc level is greater than 70 µg/dL; however, normal levels do not rule out deficiency.¹⁸ Measurement of zinc-dependent enzymes, such as alkaline phosphatase, can be a quick way to assess zinc status. Serum albumin also should be measured; because zinc is carried by albumin in the blood, hypoalbuminemia may result in secondary zinc deficiency.¹⁸

Zinc replacement therapy is largely through oral supplementation and should start at 0.5 to 2.0 mg/kg/d in adults with acquired disease.^29,30 Zinc sulfate is the most affordable and is the supplement of choice, with 50 mg of elemental zinc per 220 mg of zinc sulfate (~23% elemental zinc).³¹ Alternative zinc salts, such as zinc gluconate (13% elemental zinc), may be used. Patients with malabsorptive disorders often require parenteral supplementation.³² Clinical symptoms often will resolve within 1 to 2 weeks of supplementation.²⁹ In patients with primary acrodermatitis enteropathica, lifelong supplementation with 3 mg/kg/d elemental zinc should occur.⁶ Calcium and folate may reduce zinc absorption, while zinc supplementation can interfere with copper and iron absorption.³³

Iron Deficiency

Iron is an essential component of the hemoglobin molecule. Iron homeostasis and metabolism are tightly regulated processes that drive erythropoiesis. Only 5% to 10% of dietary iron is absorbed through nutrition, while the remainder is recycled from red cell breakdown. Both normal iron levels and iron deficiency (ID) are defined by age and gender.³⁴ Iron-deficiency anemia (IDA) is one of the most common cause-specific anemias worldwide.³⁵

Fatigue is the most common and earliest symptom of ID. In a single study, pallor was predictive of anemia in hospitalized patients; however, absence of pallor did not rule out anemia.³⁴ Dyspnea on exertion, tachycardia, dysphagia, and pica also may be reported. Cutaneous manifestations include koilonychia (Figure 2), glossitis, pruritus, angular cheilitis, and telogen effluvium. Plummer-Vinson syndrome is characterized by microcytic anemia, glossitis, and dysphagia.

Iron deficiency can be present despite a normal hemoglobin level. Serum ferritin and percentage transferrin saturation are key to early identification of IDA.³⁵ Ferritin levels lower than 30 µg/L confirm the diagnosis. Decreased transferrin saturation and increased total iron binding capacity aid in the diagnosis of IDA. Serum ferritin is an acute-phase reactant, and levels may be falsely elevated in the setting of inflammation or infection.

Essential Fatty Acid Deficiency

Essential fatty acids (EFAs) including linoleic and α-linolenic acid cannot be synthesized by the human body and must be obtained through diet (mostly plant oils). Essential fatty acids have various functions, including maintaining phospholipid membrane integrity, forming prostaglandins and leukotrienes, and storing energy.⁴⁰ Essential fatty acids are important in the structure and function of the stratum corneum and are crucial in maintaining epidermal barrier function.⁴¹ Increased epidermal permeability and transepidermal water loss may be the first signs of EFA deficiency (EFAD).⁴²

The cutaneous manifestations of EFAD include xerosis, weeping eczematous plaques, and erosions in intertriginous sites. The lesions may progress to widespread desquamation and erythema. With time, the skin can become thick and leathery. Alopecia may occur, and hair may depigment.⁷ Additional findings include poor wound healing and increased susceptibility to infections.^43,44

Essential fatty acid deficiency may occur when dietary fat intake is severely restricted or in malabsorptive states.^45,46 It develops in patients on prolonged TPN, typically when receiving fat-restricted nutrition,^47,48 as occurs in hypertriglyceridemia.⁴⁷ Essential fatty acid deficiency has developed in patients on TPN containing EFAs,⁴⁷ as the introduction of novel intravenous lipid emulsions has resulted in varying proportions of EFA.⁴⁰ Premature neonates are particularly at risk for EFAD.⁴⁹

The diagnosis of EFAD involves the measurement of the triene to tetraene ratio. A ratio of more than 0.2 suggests EFAD, but the clinical signs are not seen until the ratio is over 0.4.⁴⁰ Low plasma levels of linoleic, linolenic, and arachidonic acids also are seen. Elevated liver function tests are supportive of the diagnosis. Biochemical findings typically are seen before cutaneous manifestations.⁴⁰

Treatment of EFAD includes topical, oral, or intravenous replacement of EFAs. Improvement of EFAD with the application of topical linoleic acid to the skin has been reported.⁵⁰ Patients receiving TPN should undergo assessment of parenteral lipid emulsion to ensure adequate fatty acid composition.

Vitamin A Deficiency

Vitamin A (retinol) is a fat-soluble vitamin that plays a critical role in keratinization, epithelial proliferation, and cellular differentiation.⁶ Vitamin A is found in animal products as retinyl esters and in plants as beta-carotene. Vitamin A has 2 clinically important forms: all-trans retinoic acid and 11-cis-retinal. All-trans retinoic acid is involved in cellular differentiation and regulating gene transcription, while 11-cis-retinal is key to rhodopsin generation required for vision. Vitamin A deficiency presents with early ophthalmologic findings, specifically nyctalopia, or delayed adaptation to the dark.⁵¹ Xerophthalmia, abnormal conjunctival keratinization, and Bitot spots subsequently develop and may progress to corneal ulceration and blindness.⁶

Vitamin A deficiency manifests in the skin as follicular hyperkeratosis, or phrynoderma. Notably, numerous other micronutrient deficiencies may result in phrynoderma. Clinically, multiple pigmented keratotic papules of various sizes, many with a central keratinous plug, are distributed symmetrically on the extensor elbows, knees, shoulders, buttocks, and extremities. The skin surrounding these lesions may be scaly and hyperpigmented.⁵² Generalized xerosis without preceding nyctalopia has been reported.⁵³ Accompanying pityriasis alba may develop.⁵² Lesions on the face may mimic acne, while lesions on the extremities may simulate a perforating disorder. Histopathology of phrynoderma reveals epidermal hyperkeratosis, follicular hyperkeratosis, and follicular plugging.⁵²

Vitamin A deficiency can be diagnosed by measuring serum retinol levels, with levels lower than 20 µg/dL being diagnostic of deficiency.⁵⁶ Decreased serum retinol in patients hospitalized with flaring irritable bowel disorder has been repeatedly reported.^57-59 Notably, serum retinol concentration does not decline until liver reserves of vitamin A are nearing exhaustion.³³

The US Food and Drug Administration requires manufacturers to list retinol activity equivalents on labels. One international unit of retinol is equivalent to 0.3 µg of retinol activity equivalents.⁶⁰ The treatment of vitamin A deficiency involves high-dose oral supplementation when possible.⁶¹ Although dependent on age, the treatment dose for most adults with vitamin A deficiency is 3000 µg (10,000 IU) once daily.

Phrynoderma has been specifically treated with salicylic acid ointment 3% and intramuscular vitamin A.⁶² Topical urea cream also may treat phrynoderma.⁶³

Vitamin B₂

Vitamin B₂ (riboflavin) is absorbed in the small intestine and converted into 2 biologically active forms—flavin adenine dinucleotide and flavin mononucleotide—which serve as cofactors in metabolic and oxidation-reduction reactions. Malabsorptive disorders and bowel resection can lead to riboflavin deficiency.⁶⁴ Other at-risk populations include those with restrictive diets,⁶⁵ psychiatric illness, or systemic illness (eTable). Riboflavin can be degraded by light (deficiency has been reported after phototherapy for neonatal jaundice⁶⁶) and following boric acid ingestion.⁶⁷ Medications, including long-term treatment with antiepileptics, may lead to riboflavin deficiency.⁶⁸

Riboflavin is critical to maintaining collagen production. Riboflavin deficiency may manifest clinically with extensive seborrheiclike dermatitis,⁴⁴ intertrigolike dermatitis,⁶⁹ or oral-ocular-genital syndrome.⁷⁰ Angular cheilitis may accompany an atrophic tongue that is deep red in color. The scrotum is characteristically involved in men, with confluent dermatitis extending onto the thighs and sparing the midline. Red papules and painful fissures may develop. Balanitis and phimosis have been reported. Testing for riboflavin deficiency should be considered in patients with refractory seborrheic dermatitis.

Riboflavin stores are assessed by the erythrocyte glutathione reductase activity coefficient.⁴⁴ A level of 1.4 or higher is consistent with deficiency. Serum riboflavin levels, performed after a 12-hour fast, may support the diagnosis but are less sensitive. Patients with glucose-6-phosphate deficiency cannot be assessed via the erythrocyte glutathione reductase activity coefficient and may instead require evaluation of 24-hour urine riboflavin level.⁴⁴

Vitamin B₃

Vitamin B₃ (niacin, nicotinamide, nicotinic acid) is found in plant and animal products or can be derived from its amino acid precursor tryptophan. Niacin deficiency results in pellagra, characterized by dermatitis, dementia, and diarrhea.⁷¹ The most prominent feature is a symmetrically distributed photosensitive dermatitis of the face, neck (called Casal necklace)(Figure 3), chest, dorsal hands, and extensor arms. The eruption may begin with erythema, vesicles, or bullae (wet pellagra) and evolve into thick, hyperpigmented, scaling plaques.⁷¹ The skin may take on a copper tone and become atrophic.⁷² Dull erythema with overlying yellow powdery scale (called sulfur flakes) at follicular orifices has been described on the nasal bridge.⁷³

Causes of niacin deficiency include malabsorptive conditions, malignancy (including carcinoid tumors), parenteral nutrition, psychiatric disease,^74,75 and restrictive diets (eTable).⁷⁶ Carcinoid tumors divert tryptophan to serotonin resulting in niacin deficiency.⁷⁷

The diagnosis of niacin deficiency is based on clinical findings and response to supplementation.⁷⁵ Low niacin urinary metabolites (N-methylnicotinamide and 2-pyridone) may aid in diagnosis.⁶ Treatment generally includes oral nicotinamide 100 mg every 6 hours; the dose can then be tapered to 50 mg every 8 to 12 hours until symptoms resolve. Severe deficiency may require parenteral nicotinamide 1 g 3 to 4 times daily.⁷⁵

Vitamin B₆

Vitamin B₆ (pyridoxine, pyridoxamine, pyridoxal) is found in whole grains and plant and animal products. Vitamin B₆ functions as a coenzyme in many metabolic pathways and is involved in the conversion of tryptophan to niacin.⁴⁴ Absorption requires hydrolysis by intestinal phosphates and transport to the liver for rephosphorylation prior to release in active form.⁶

Cutaneous findings associated with vitamin B₆ deficiency include periorificial and perineal seborrheic dermatitis,⁷⁸ angular stomatitis, and cheilitis, with associated burning, redness, and tongue edema.⁶ Vitamin B₆ deficiency is a rarely reported cause of burning mouth syndrome.⁷⁹ Because vitamin B₆ is involved in the conversion of tryptophan to niacin, deficiency also may present with pellagralike findings.⁷⁰ Other clinical symptoms are outlined in the eTable.^80,81

Conditions that increase risk for vitamin B₆ deficiency are highlighted in the eTable and include malabsorptive disorders; psychiatric illness⁸²; and chronic disease, especially end-stage renal disease.⁸³ Vitamin B₆ deficiency associated with chronic alcohol use is due to both inadequate vitamin B₆ intake as well as reduced hepatic storage.⁷⁸ Medications such as isoniazid, hydralazine, and oral contraceptives may decrease vitamin B₆ levels (eTable).⁸²

Vitamin B₆ can be measured in the plasma as pyridoxal 5′-phosphate. Plasma concentrations of less than 20 nmol/L are suggestive of deficiency.⁸² Indirect tests include tryptophan and methionine loading.⁶ The treatment of vitamin B₆ deficiency is determined by symptom severity. Recommendations for oral supplementation range from 25 to 600 mg daily.⁸² Symptoms typically improve on 100 mg daily.⁶

Vitamins B₉ and B₁₂

Deficiencies of vitamins B₉ (folic acid, folate) and B₁₂ (cobalamin) have similar clinical presentations. Folate is essential in the metabolism of amino acids, purines, and pyrimidines.⁶ Cobalamin, found in animal products, is a cofactor for methionine synthase and methylmalonyl-CoA mutase.⁸⁴ Megaloblastic anemia is the main finding in folate or cobalamin deficiency. Neurologic findings only accompany cobalamin deficiency. Risk factors for folate deficiency include malabsorptive conditions,⁶ chronic alcohol use,⁸⁵ and antifolate medication use (eTable).⁶

Cobalamin absorption requires gastric acid and intrinsic factor binding in the duodenum. Deficiency may occur from strict diets, psychiatric illness, old age,⁸⁶ decreased gastric acid secretion,⁸⁷ abnormal intrinsic factor function, or intestinal infections.⁶

Generalized cutaneous hyperpigmentation may be the first manifestation of vitamins B₉ and B₁₂ deficiency.⁸⁸ Typically accentuated in acral creases and the oral cavity, pigmentation may mimic Addison disease. Hair depigmentation and linear streaking of the nails are reported.⁸⁴ The tongue becomes painful and red with atrophy of the filiform papillae (Hunter glossitis).⁷⁸ Linear lesions on the tongue and hard palate may serve as an early sign of cobalamin deficiency.⁸⁹

Folate deficiency is diagnosed by measuring the plasma folate level; coincidental cobalamin deficiency should be excluded. Deficiency is managed with oral supplementation (when possible) with 1 to 5 mg of folate daily.⁶ Cobalamin deficiency is based on low serum levels (<150 pg/mL is diagnostic).⁸⁶ Cobalamin deficiency may take years to develop, as vitamin B₁₂ exists in large body stores.⁶ Serum methylmalonic acid may be elevated in patients with clinical features but normal-low serum vitamin B₁₂ level.⁸⁶ Treatment of vitamin B₁₂ deficiency is with oral (2 mg once daily) or parenteral (1 mg every 4 weeks then maintained at once monthly) cyanocobalamin. For patients with neurologic symptoms, intramuscular injection should be given.⁸⁶ The underlying cause of deficiency must be elucidated and treated.

Vitamin C Deficiency

Vitamin C (ascorbic acid) is an essential cofactor for the hydroxylation of proline and lysine residues in collagen synthesis. Plant-based foods are the main dietary source of vitamin C, and deficiency presents clinically as scurvy. Cutaneous findings include follicular hyperkeratosis, perifollicular petechiae, and curled hair shafts (corkscrew hairs)(Figure 4). Ecchymoses of the lower extremities, forearms, and abdomen may be seen. Nodules representing intramuscular and subcutaneous hemorrhage can be present.⁹⁰ Woody edema may mimic cellulitis, while lower extremity hemorrhage may mimic vasculitis. Gingival hyperplasia, hemorrhage, and edema may occur,⁹⁰ along with linear splinter hemorrhages.⁹¹

Hypovitaminosis C has been routinely demonstrated in hospitalized patients.⁹² Scurvy may occur in patients on strict diets,⁹³ chronic alcohol use,⁹⁴ psychiatric illness,⁹⁵ or gastrointestinal tract disease (eTable).^96-99 Those with low socioeconomic status⁷⁰ or dementia¹⁰⁰ as well as the elderly also are at risk.¹⁰¹ Scurvy has developed in patients with iron overload and those who are on hemodialysis⁴⁴ as well as in association with nilotinib use.¹⁰² Patients with chronic mucous membrane graft-vs-host disease may exhibit vitamin C deficiency.¹⁰³

Scurvy is a clinical diagnosis. Vitamin C levels normalize quickly with supplementation. Cutaneous biopsy will exhibit follicular hyperkeratosis, perifollicular hemorrhage, and fibrosis.⁹¹

Oral ascorbic acid supplementation should be initiated at 500 to 1000 mg daily in adults.¹⁰⁴ The cause of deficiency should be identified, and further supplementation should be decided based on patient risk factors. Lifestyle modifications, such as cessation of smoking and chronic alcohol use, is recommended. The diagnosis of scurvy should prompt workup for additional nutrient deficiencies.

Final Thoughts

Dermatologists play an important role in the early recognition of nutritional deficiencies, as cutaneous manifestations often are the first clue to diagnosis. Nutritional deficiencies are common yet underrecognized in the hospitalized patient and serve as an independent risk factor for patient morbidity and mortality.³ Awareness of the cutaneous manifestations of undernutrition as well as the risk factors for nutritional deficiency may expedite diagnosis and supplementation, thereby improving outcomes for hospitalized patients.

What constitutes a structural lesion of the sacroiliac joints on MRI that’s indicative of axial spondyloarthritis (axSpA) has long been a matter of conjecture, but the Assessment of SpondyloArthritis International Society (ASAS) MRI Working Group has developed new definitions that showed a high degree of specificity in identifying such lesions in the disease.

“There is a lack of consensus as to what defines a structural lesion on MRI of the sacroiliac joint [SIJ] typical of axial spondyloarthritis. Previous studies have described structural lesions in different ways, precluding meaningful comparisons between studies. The ASAS MRI group has generated updated consensus lesion definitions that describe each of the MRI lesions in the sacroiliac joint. These definitions have been validated by seven expert readers from the ASAS MRI group on MRI images from the ASAS classification cohort,” Walter P. Maksymowych, MD, said at the annual European Congress of Rheumatology, held online this year due to COVID-19.

Making a definitive diagnosis of axSpA can be difficult because MRI can show a variety of SIJ abnormalities in healthy people as well as those with axSpA, said Dr. Maksymowych, chief medical officer of CARE Arthritis and professor in rheumatology at the University of Alberta in Edmonton, said in an interview prior to his presentation at the e-congress. “People who evaluate MRI scans are looking for clues as to what types of lesions they can be confident are indicative of axSpA.”

That started a process by the ASAS MRI group to evaluate scans from the landmark ASAS Classification Cohort study (Ann Rheum Dis. 2019;78:1550-8). “But,” said Dr. Maksymowych, “the MRI scans from that study were never evaluated.” So that work was handed off to the working group, whose 25 members included 7 expert image readers who evaluated the MRI scans.

The group adopted a standardized approach for evaluating MRIs of the SIJ in 148 cases, dividing each SIJ into quadrants and then evaluating consecutive MRI slices. The readers first documented whether they observed a definite structural lesion on the scan, which they then used as an external reference standard. They then analyzed which lesion, and in how many SIJ quadrants or slices, best reflected this external standard.

Courtesy Dr. Walter P. Maksymowych

The investigators defined an erosion as “a defect in subchondral bone associated with full-thickness loss of a dark appearance of the subchondral cortex at its expected location, with loss of signal on a T1-weighted, non–fat-suppressed sequence, compared with the normal bright appearance of adjacent bone marrow.” They defined a fat lesion or fat metaplasia as a “bright signal seen on a T1-weighted, non–fat-suppressed sequence that is brighter than normal bone marrow which meets the following requirements: It is homogeneously bright, located in a typical anatomical area (specifically subchondral bone), and has a sharply defined border along its nonarticular border with normal bone marrow.”

An erosion in one quadrant isn’t sufficient to define a scan as positive for a definite structural lesion, said Dr. Maksymowych; but an erosion in three quadrants or in two or more consecutive slices meets the group’s designation of a definite structural lesion. “This showed over a 95% specificity for being associated with a definite structural lesion as defined by a majority of the seven experts,” he said.

The group also determined that a fat lesion typical of axSpA has a homogeneous white appearance on T1-weighted scans with a sharply defined border. The group also determined that such a fat lesion with at least 1-cm horizontal depth from the joint margin in at least one SIJ quadrant is strongly indicative of axSpA.

Courtesy Dr. Walter P. Maksymowych

“So we now have definitions for two structural lesions, erosion and fat lesions, that reflect what a majority of experts consider to be a definite structural lesion according to at least 95% specificity,” he said. Sensitivity values were 90% for erosion in three quadrants and 83% for erosions in two or more consecutive slices. and 59% for a fat lesion with at least 1-cm horizontal depth from the joint margin in at least one SIJ quadrant.

The second part of the analysis evaluated the predictive capacity of these lesion definitions for a rheumatologic diagnosis of axSpA at 4.4 years of follow-up. “These lesions predicted SpA with over 95% positive predictive value,” he said. “In other words, if you see them at baseline they’re going to predict SpA with high certainty at follow-up after 4.4 years.”

Three aspects of this study design are unique, Dr. Maksymowych noted. First is the high number of expert MRI readers who evaluated the scans. “There aren’t really too many studies I can think of that used more than two or three expert MRI readers,” he said.

Second is the way in which the study “very precisely and in a very standardized way” applied all the consensus-based ASAS definitions of structural SIJ lesions. “In the past, a variety of ways were used to define these lesions,” he said. “A good example would be the different ways in which erosions have been defined.”

The third novel aspect of the study is that the expert readers’ assessment of what constitutes a definite structural lesion was used as an external reference standard. For example, the study calculated sensitivity and specificity for numbers of SIJ quadrants and consecutive slices with erosion, sclerosis, and fat lesions where a majority of readers agreed on the presence of a structural lesion typical of axSpA with high confidence (3 or greater on a scale of 1-4). “The reason this was put in place is because we recognize sometimes lesions are very subtle and you can’t be certain that they’re reflecting SpA,” he said.

The investigators disclosed relationships with AbbVie, Amgen, Astellas, AstraZeneca, Bristol-Myers Squibb, Boehringer Ingelheim, Celgene, Eli Lilly, Galapagos, Janssen, Merck, Novo Nordisk, Novartis, Orion, Pfizer, Regeneron, Roche, Sandoz, Sanofi, and UCB.

Maksymowych WP et al. Ann Rheum Dis, 2020;79[suppl 1]:53. Abstract OP0079.

What constitutes a structural lesion of the sacroiliac joints on MRI that’s indicative of axial spondyloarthritis (axSpA) has long been a matter of conjecture, but the Assessment of SpondyloArthritis International Society (ASAS) MRI Working Group has developed new definitions that showed a high degree of specificity in identifying such lesions in the disease.

“There is a lack of consensus as to what defines a structural lesion on MRI of the sacroiliac joint [SIJ] typical of axial spondyloarthritis. Previous studies have described structural lesions in different ways, precluding meaningful comparisons between studies. The ASAS MRI group has generated updated consensus lesion definitions that describe each of the MRI lesions in the sacroiliac joint. These definitions have been validated by seven expert readers from the ASAS MRI group on MRI images from the ASAS classification cohort,” Walter P. Maksymowych, MD, said at the annual European Congress of Rheumatology, held online this year due to COVID-19.

Making a definitive diagnosis of axSpA can be difficult because MRI can show a variety of SIJ abnormalities in healthy people as well as those with axSpA, said Dr. Maksymowych, chief medical officer of CARE Arthritis and professor in rheumatology at the University of Alberta in Edmonton, said in an interview prior to his presentation at the e-congress. “People who evaluate MRI scans are looking for clues as to what types of lesions they can be confident are indicative of axSpA.”

That started a process by the ASAS MRI group to evaluate scans from the landmark ASAS Classification Cohort study (Ann Rheum Dis. 2019;78:1550-8). “But,” said Dr. Maksymowych, “the MRI scans from that study were never evaluated.” So that work was handed off to the working group, whose 25 members included 7 expert image readers who evaluated the MRI scans.

The group adopted a standardized approach for evaluating MRIs of the SIJ in 148 cases, dividing each SIJ into quadrants and then evaluating consecutive MRI slices. The readers first documented whether they observed a definite structural lesion on the scan, which they then used as an external reference standard. They then analyzed which lesion, and in how many SIJ quadrants or slices, best reflected this external standard.

Courtesy Dr. Walter P. Maksymowych

The investigators defined an erosion as “a defect in subchondral bone associated with full-thickness loss of a dark appearance of the subchondral cortex at its expected location, with loss of signal on a T1-weighted, non–fat-suppressed sequence, compared with the normal bright appearance of adjacent bone marrow.” They defined a fat lesion or fat metaplasia as a “bright signal seen on a T1-weighted, non–fat-suppressed sequence that is brighter than normal bone marrow which meets the following requirements: It is homogeneously bright, located in a typical anatomical area (specifically subchondral bone), and has a sharply defined border along its nonarticular border with normal bone marrow.”

An erosion in one quadrant isn’t sufficient to define a scan as positive for a definite structural lesion, said Dr. Maksymowych; but an erosion in three quadrants or in two or more consecutive slices meets the group’s designation of a definite structural lesion. “This showed over a 95% specificity for being associated with a definite structural lesion as defined by a majority of the seven experts,” he said.

The group also determined that a fat lesion typical of axSpA has a homogeneous white appearance on T1-weighted scans with a sharply defined border. The group also determined that such a fat lesion with at least 1-cm horizontal depth from the joint margin in at least one SIJ quadrant is strongly indicative of axSpA.

Courtesy Dr. Walter P. Maksymowych

“So we now have definitions for two structural lesions, erosion and fat lesions, that reflect what a majority of experts consider to be a definite structural lesion according to at least 95% specificity,” he said. Sensitivity values were 90% for erosion in three quadrants and 83% for erosions in two or more consecutive slices. and 59% for a fat lesion with at least 1-cm horizontal depth from the joint margin in at least one SIJ quadrant.

The second part of the analysis evaluated the predictive capacity of these lesion definitions for a rheumatologic diagnosis of axSpA at 4.4 years of follow-up. “These lesions predicted SpA with over 95% positive predictive value,” he said. “In other words, if you see them at baseline they’re going to predict SpA with high certainty at follow-up after 4.4 years.”

Three aspects of this study design are unique, Dr. Maksymowych noted. First is the high number of expert MRI readers who evaluated the scans. “There aren’t really too many studies I can think of that used more than two or three expert MRI readers,” he said.

Second is the way in which the study “very precisely and in a very standardized way” applied all the consensus-based ASAS definitions of structural SIJ lesions. “In the past, a variety of ways were used to define these lesions,” he said. “A good example would be the different ways in which erosions have been defined.”

The third novel aspect of the study is that the expert readers’ assessment of what constitutes a definite structural lesion was used as an external reference standard. For example, the study calculated sensitivity and specificity for numbers of SIJ quadrants and consecutive slices with erosion, sclerosis, and fat lesions where a majority of readers agreed on the presence of a structural lesion typical of axSpA with high confidence (3 or greater on a scale of 1-4). “The reason this was put in place is because we recognize sometimes lesions are very subtle and you can’t be certain that they’re reflecting SpA,” he said.

The investigators disclosed relationships with AbbVie, Amgen, Astellas, AstraZeneca, Bristol-Myers Squibb, Boehringer Ingelheim, Celgene, Eli Lilly, Galapagos, Janssen, Merck, Novo Nordisk, Novartis, Orion, Pfizer, Regeneron, Roche, Sandoz, Sanofi, and UCB.

Maksymowych WP et al. Ann Rheum Dis, 2020;79[suppl 1]:53. Abstract OP0079.

What constitutes a structural lesion of the sacroiliac joints on MRI that’s indicative of axial spondyloarthritis (axSpA) has long been a matter of conjecture, but the Assessment of SpondyloArthritis International Society (ASAS) MRI Working Group has developed new definitions that showed a high degree of specificity in identifying such lesions in the disease.

“There is a lack of consensus as to what defines a structural lesion on MRI of the sacroiliac joint [SIJ] typical of axial spondyloarthritis. Previous studies have described structural lesions in different ways, precluding meaningful comparisons between studies. The ASAS MRI group has generated updated consensus lesion definitions that describe each of the MRI lesions in the sacroiliac joint. These definitions have been validated by seven expert readers from the ASAS MRI group on MRI images from the ASAS classification cohort,” Walter P. Maksymowych, MD, said at the annual European Congress of Rheumatology, held online this year due to COVID-19.

Making a definitive diagnosis of axSpA can be difficult because MRI can show a variety of SIJ abnormalities in healthy people as well as those with axSpA, said Dr. Maksymowych, chief medical officer of CARE Arthritis and professor in rheumatology at the University of Alberta in Edmonton, said in an interview prior to his presentation at the e-congress. “People who evaluate MRI scans are looking for clues as to what types of lesions they can be confident are indicative of axSpA.”

That started a process by the ASAS MRI group to evaluate scans from the landmark ASAS Classification Cohort study (Ann Rheum Dis. 2019;78:1550-8). “But,” said Dr. Maksymowych, “the MRI scans from that study were never evaluated.” So that work was handed off to the working group, whose 25 members included 7 expert image readers who evaluated the MRI scans.

The group adopted a standardized approach for evaluating MRIs of the SIJ in 148 cases, dividing each SIJ into quadrants and then evaluating consecutive MRI slices. The readers first documented whether they observed a definite structural lesion on the scan, which they then used as an external reference standard. They then analyzed which lesion, and in how many SIJ quadrants or slices, best reflected this external standard.

Courtesy Dr. Walter P. Maksymowych

The investigators defined an erosion as “a defect in subchondral bone associated with full-thickness loss of a dark appearance of the subchondral cortex at its expected location, with loss of signal on a T1-weighted, non–fat-suppressed sequence, compared with the normal bright appearance of adjacent bone marrow.” They defined a fat lesion or fat metaplasia as a “bright signal seen on a T1-weighted, non–fat-suppressed sequence that is brighter than normal bone marrow which meets the following requirements: It is homogeneously bright, located in a typical anatomical area (specifically subchondral bone), and has a sharply defined border along its nonarticular border with normal bone marrow.”

An erosion in one quadrant isn’t sufficient to define a scan as positive for a definite structural lesion, said Dr. Maksymowych; but an erosion in three quadrants or in two or more consecutive slices meets the group’s designation of a definite structural lesion. “This showed over a 95% specificity for being associated with a definite structural lesion as defined by a majority of the seven experts,” he said.

The group also determined that a fat lesion typical of axSpA has a homogeneous white appearance on T1-weighted scans with a sharply defined border. The group also determined that such a fat lesion with at least 1-cm horizontal depth from the joint margin in at least one SIJ quadrant is strongly indicative of axSpA.

Courtesy Dr. Walter P. Maksymowych

“So we now have definitions for two structural lesions, erosion and fat lesions, that reflect what a majority of experts consider to be a definite structural lesion according to at least 95% specificity,” he said. Sensitivity values were 90% for erosion in three quadrants and 83% for erosions in two or more consecutive slices. and 59% for a fat lesion with at least 1-cm horizontal depth from the joint margin in at least one SIJ quadrant.

The second part of the analysis evaluated the predictive capacity of these lesion definitions for a rheumatologic diagnosis of axSpA at 4.4 years of follow-up. “These lesions predicted SpA with over 95% positive predictive value,” he said. “In other words, if you see them at baseline they’re going to predict SpA with high certainty at follow-up after 4.4 years.”

Three aspects of this study design are unique, Dr. Maksymowych noted. First is the high number of expert MRI readers who evaluated the scans. “There aren’t really too many studies I can think of that used more than two or three expert MRI readers,” he said.

Second is the way in which the study “very precisely and in a very standardized way” applied all the consensus-based ASAS definitions of structural SIJ lesions. “In the past, a variety of ways were used to define these lesions,” he said. “A good example would be the different ways in which erosions have been defined.”

The third novel aspect of the study is that the expert readers’ assessment of what constitutes a definite structural lesion was used as an external reference standard. For example, the study calculated sensitivity and specificity for numbers of SIJ quadrants and consecutive slices with erosion, sclerosis, and fat lesions where a majority of readers agreed on the presence of a structural lesion typical of axSpA with high confidence (3 or greater on a scale of 1-4). “The reason this was put in place is because we recognize sometimes lesions are very subtle and you can’t be certain that they’re reflecting SpA,” he said.

The investigators disclosed relationships with AbbVie, Amgen, Astellas, AstraZeneca, Bristol-Myers Squibb, Boehringer Ingelheim, Celgene, Eli Lilly, Galapagos, Janssen, Merck, Novo Nordisk, Novartis, Orion, Pfizer, Regeneron, Roche, Sandoz, Sanofi, and UCB.

Maksymowych WP et al. Ann Rheum Dis, 2020;79[suppl 1]:53. Abstract OP0079.

Case Report

A 92-year-old Eastern European woman presented to our nail clinic with a history of onychodystrophy and arthralgia of the digits of several months’ duration. Her dermatologic history was notable for irritant hand dermatitis. A prior nail plate clipping with histopathologic examination was negative for fungal elements. Physical examination revealed onychorrhexis of all fingernails as well as onycholysis and subungual hyperkeratosis of the right fourth fingernail. Blue-green staining was incidentally noted on the right second and third fingernails and nail folds (Figure 1). Contact dermoscopy using ultrasound gel revealed translucent areas with sparse pigment, though denser areas had a fine branching pattern (Figure 2). When questioned, the patient reported use of “zelyonka,” a brilliant green solution, to self-treat the nails. Histopathology on repeat nail clippings showed parakeratosis and serum, which was most consistent with her known history of irritant hand dermatitis. Radiographs of the hands revealed osteoarthritis that was most prominent at the distal interphalangeal joints.

Comment

Brilliant green is a triphenylmethane dye commonly used in Eastern Europe and other regions for the treatment of superficial skin infections and onychomycosis.¹ Its use as an antiseptic and wound healing agent has been investigated in the scientific literature since at least the early 20th century.² Brilliant green typically is applied in a 0.1% to 2% ethanol solution.¹ The dye has bactericidal activity against gram-positive organisms, particularly staphylococci and streptococci.^2,3 It has been used for the treatment of fungal skin and nail infections since at least the early 20th century, with anecdotal success.⁴ Although there have been no studies investigating use of brilliant green alone for the treatment of onychomycosis, it is sometimes used in combination with conventional oral agents for this purpose.⁵ Because of its availability, safety, ease of use, and low cost, brilliant green has been promoted as an antiseptic in resource-poor settings.³ The revival of brilliant green and other antiseptic dyes in these settings has been suggested as an alternative to oral antibiotic agents, to which resistance is rising, and as a potential cancer therapy.^6,7 Although brilliant green’s mechanism of action in treating skin infections is unclear, it has been shown to form covalent adducts with thioredoxin reductase 2, a protein conserved from bacteria to humans with an essential function for cellular activity.⁷

Early case studies suggested that brilliant green was beneficial in treating wounds²; however, this indication is controversial. In a guinea pig study, brilliant green was shown to inhibit wound healing and the formation of granulation tissue.⁸ It also should be noted that when used topically, brilliant green may cause skin sensitization, necrotic skin reactions, and permanent staining of clothing. It has no known anti-inflammatory properties and also may cause skin irritation.⁸ Brilliant green may cause blindness if it comes in contact with the eyes.¹

Brilliant green has other potential dermatologic indications. For example, a combination of brilliant green and gentian violet, a related dye, has demonstrated efficacy in the treatment of cutaneous hemangiomas in mouse models by blocking expression of angiopoietin-2.⁷

Dermatologists should be familiar with brilliant green and its common uses as well as adverse effects. Brilliant green is commercially available for a low cost ($5 to $20) in specialty pharmacies or online (eg, Amazon). It is sold alone or in combination with gentian violet and proflavine hemisulfate, and a prescription is not required. Due to its low cost and accessibility, patients may use brilliant green to self-treat dermatologic conditions. Green nails due to staining with brilliant green dye must be distinguished from other etiologies causing green nail discoloration, such as infection with Pseudomonas aeruginosa or Aspergillus, bullous disorders, jaundice, “old” hematomas, nail polish, and other exogenous pigments.

Case Report

A 92-year-old Eastern European woman presented to our nail clinic with a history of onychodystrophy and arthralgia of the digits of several months’ duration. Her dermatologic history was notable for irritant hand dermatitis. A prior nail plate clipping with histopathologic examination was negative for fungal elements. Physical examination revealed onychorrhexis of all fingernails as well as onycholysis and subungual hyperkeratosis of the right fourth fingernail. Blue-green staining was incidentally noted on the right second and third fingernails and nail folds (Figure 1). Contact dermoscopy using ultrasound gel revealed translucent areas with sparse pigment, though denser areas had a fine branching pattern (Figure 2). When questioned, the patient reported use of “zelyonka,” a brilliant green solution, to self-treat the nails. Histopathology on repeat nail clippings showed parakeratosis and serum, which was most consistent with her known history of irritant hand dermatitis. Radiographs of the hands revealed osteoarthritis that was most prominent at the distal interphalangeal joints.

Comment

Brilliant green is a triphenylmethane dye commonly used in Eastern Europe and other regions for the treatment of superficial skin infections and onychomycosis.¹ Its use as an antiseptic and wound healing agent has been investigated in the scientific literature since at least the early 20th century.² Brilliant green typically is applied in a 0.1% to 2% ethanol solution.¹ The dye has bactericidal activity against gram-positive organisms, particularly staphylococci and streptococci.^2,3 It has been used for the treatment of fungal skin and nail infections since at least the early 20th century, with anecdotal success.⁴ Although there have been no studies investigating use of brilliant green alone for the treatment of onychomycosis, it is sometimes used in combination with conventional oral agents for this purpose.⁵ Because of its availability, safety, ease of use, and low cost, brilliant green has been promoted as an antiseptic in resource-poor settings.³ The revival of brilliant green and other antiseptic dyes in these settings has been suggested as an alternative to oral antibiotic agents, to which resistance is rising, and as a potential cancer therapy.^6,7 Although brilliant green’s mechanism of action in treating skin infections is unclear, it has been shown to form covalent adducts with thioredoxin reductase 2, a protein conserved from bacteria to humans with an essential function for cellular activity.⁷

Early case studies suggested that brilliant green was beneficial in treating wounds²; however, this indication is controversial. In a guinea pig study, brilliant green was shown to inhibit wound healing and the formation of granulation tissue.⁸ It also should be noted that when used topically, brilliant green may cause skin sensitization, necrotic skin reactions, and permanent staining of clothing. It has no known anti-inflammatory properties and also may cause skin irritation.⁸ Brilliant green may cause blindness if it comes in contact with the eyes.¹

Brilliant green has other potential dermatologic indications. For example, a combination of brilliant green and gentian violet, a related dye, has demonstrated efficacy in the treatment of cutaneous hemangiomas in mouse models by blocking expression of angiopoietin-2.⁷

Dermatologists should be familiar with brilliant green and its common uses as well as adverse effects. Brilliant green is commercially available for a low cost ($5 to $20) in specialty pharmacies or online (eg, Amazon). It is sold alone or in combination with gentian violet and proflavine hemisulfate, and a prescription is not required. Due to its low cost and accessibility, patients may use brilliant green to self-treat dermatologic conditions. Green nails due to staining with brilliant green dye must be distinguished from other etiologies causing green nail discoloration, such as infection with Pseudomonas aeruginosa or Aspergillus, bullous disorders, jaundice, “old” hematomas, nail polish, and other exogenous pigments.

Case Report

A 92-year-old Eastern European woman presented to our nail clinic with a history of onychodystrophy and arthralgia of the digits of several months’ duration. Her dermatologic history was notable for irritant hand dermatitis. A prior nail plate clipping with histopathologic examination was negative for fungal elements. Physical examination revealed onychorrhexis of all fingernails as well as onycholysis and subungual hyperkeratosis of the right fourth fingernail. Blue-green staining was incidentally noted on the right second and third fingernails and nail folds (Figure 1). Contact dermoscopy using ultrasound gel revealed translucent areas with sparse pigment, though denser areas had a fine branching pattern (Figure 2). When questioned, the patient reported use of “zelyonka,” a brilliant green solution, to self-treat the nails. Histopathology on repeat nail clippings showed parakeratosis and serum, which was most consistent with her known history of irritant hand dermatitis. Radiographs of the hands revealed osteoarthritis that was most prominent at the distal interphalangeal joints.

Comment

Brilliant green is a triphenylmethane dye commonly used in Eastern Europe and other regions for the treatment of superficial skin infections and onychomycosis.¹ Its use as an antiseptic and wound healing agent has been investigated in the scientific literature since at least the early 20th century.² Brilliant green typically is applied in a 0.1% to 2% ethanol solution.¹ The dye has bactericidal activity against gram-positive organisms, particularly staphylococci and streptococci.^2,3 It has been used for the treatment of fungal skin and nail infections since at least the early 20th century, with anecdotal success.⁴ Although there have been no studies investigating use of brilliant green alone for the treatment of onychomycosis, it is sometimes used in combination with conventional oral agents for this purpose.⁵ Because of its availability, safety, ease of use, and low cost, brilliant green has been promoted as an antiseptic in resource-poor settings.³ The revival of brilliant green and other antiseptic dyes in these settings has been suggested as an alternative to oral antibiotic agents, to which resistance is rising, and as a potential cancer therapy.^6,7 Although brilliant green’s mechanism of action in treating skin infections is unclear, it has been shown to form covalent adducts with thioredoxin reductase 2, a protein conserved from bacteria to humans with an essential function for cellular activity.⁷

Early case studies suggested that brilliant green was beneficial in treating wounds²; however, this indication is controversial. In a guinea pig study, brilliant green was shown to inhibit wound healing and the formation of granulation tissue.⁸ It also should be noted that when used topically, brilliant green may cause skin sensitization, necrotic skin reactions, and permanent staining of clothing. It has no known anti-inflammatory properties and also may cause skin irritation.⁸ Brilliant green may cause blindness if it comes in contact with the eyes.¹

Brilliant green has other potential dermatologic indications. For example, a combination of brilliant green and gentian violet, a related dye, has demonstrated efficacy in the treatment of cutaneous hemangiomas in mouse models by blocking expression of angiopoietin-2.⁷

Dermatologists should be familiar with brilliant green and its common uses as well as adverse effects. Brilliant green is commercially available for a low cost ($5 to $20) in specialty pharmacies or online (eg, Amazon). It is sold alone or in combination with gentian violet and proflavine hemisulfate, and a prescription is not required. Due to its low cost and accessibility, patients may use brilliant green to self-treat dermatologic conditions. Green nails due to staining with brilliant green dye must be distinguished from other etiologies causing green nail discoloration, such as infection with Pseudomonas aeruginosa or Aspergillus, bullous disorders, jaundice, “old” hematomas, nail polish, and other exogenous pigments.

Each year, the American Contact Dermatitis Society names an Allergen of the Year with the purpose of promoting greater awareness of a key allergen and its impact on patients. Often, the Allergen of the Year is an emerging allergen that may represent an underrecognized or novel cause of allergic contact dermatitis (ACD).In 2020, the American Contact Dermatitis Society chose isobornyl acrylate as the Allergen of the Year.¹ Not only has isobornyl acrylate been implicated in an epidemic of contact allergy to diabetic devices, but it also illustrates the challenges of investigating contact allergy to medical devices in general.

What Is Isobornyl Acrylate?

Isobornyl acrylate, also known as the isobornyl ester of acrylic acid, is a chemical used in glues, adhesives, coatings, sealants, inks, and paints. Similar to other acrylates, such as those involved in gel nail treatments, it is photopolymerizable; that is, when exposed to UV light, it can transform from a liquid monomer into a hard polymer, contributing to its utility as an adhesive. Prior to its recent implication in diabetic device contact allergy, isobornyl acrylate was not thought to be a common skin sensitizer. In a 2013 Dutch study of patients with acrylate allergy, only 1 of 14 patients with a contact allergy to other acrylates had a positive patch test reaction to isobornyl acrylate, which led the authors to conclude that adding it to their acrylate patch test series was not indicated.²

Isobornyl Acrylate in Diabetic Devices

Devices such as glucose monitoring systems and insulin pumps are used by millions of patients with diabetes worldwide. Not only are continuous glucose monitoring devices more convenient than self-monitoring of blood glucose, but they also are associated with a reduction in hemoglobin A_1c levels and lower risk for hypoglycemia.³ However, these devices have been increasingly recognized as a source of irritant contact dermatitis and ACD.

Early cases of contact allergy to isobornyl acrylate in diabetic devices were reported in 1995 when 2 Belgian patients using insulin pumps developed ACD.⁴ The patients had positive patch test reactions to isobornyl acrylate 0.1% in petrolatum and other allergens including acrylates. In addition, patch testing with plastic scrapings from their insulin pumps also was positive, and it was determined that the glue affixing the needle to the plastic had diffused into the plastic. The patients were switched to insulin pumps produced by heat staking instead of glue, and their symptoms resolved. In retrospect, this case series may seem prescient, as it was written 2 decades before isobornyl acrylate became recognized as a widespread cause of ACD in users of diabetic devices. Admittedly, other acrylate components of the glue also were positive on patch testing in these patients, so it was not until much later that the focus turned more exclusively to isobornyl acrylate.⁴

Similar to the insulin pumps in the 1995 Belgian series, diffusion of glue to other parts of modern glucose sensors also appears to cause isobornyl acrylate contact allergy. This theory was supported by a 2017 study from Belgian and Swedish investigators in which gas chromatography–mass spectrometry was used to identify concentrations of isobornyl acrylate in various components of a popular continuous glucose monitoring sensor.⁵ The concentration of isobornyl acrylate was approximately 100-fold higher at the site where the top and bottom plastic components of the sensor were joined as compared to the adhesive patch in contact with the patient’s skin. Therefore, the adhesive patch itself was not the source of the isobornyl acrylate exposure; rather, the isobornyl acrylate diffused into the adhesive patch from the glue used to join the components of the sensor together.⁵ One ramification is that patients with diabetic device contact allergy can have a false-negative patch test result if the adhesive patch is tested by itself, whereas they may react to patch testing with the whole sensor or an acetonic extract thereof.

Frequency of Sensitization to Isobornyl Acrylate

It is difficult to estimate the frequency of sensitization to isobornyl acrylate among users of diabetic devices, in part because those with mild allergy may not seek medical treatment. Nevertheless, there are studies that demonstrate a high prevalence of sensitization among users with suspected allergy. In a 2019 Finnish study of 6567 patients using an isobornyl acrylate–containing glucose sensor, 63 were patch tested for suspected ACD.⁶ Of these 63 patients, 51 (81%) had positive patch test reactions to isobornyl acrylate 0.1% in petrolatum. These findings were consistent with the original 2017 study from Belgium and Sweden, in which 10 of 11 (91%) patients who used an isobornyl acrylate–containing glucose sensor and had suspected contact allergy had positive patch test reactions to isobornyl acrylate 0.1% in petrolatum compared to no positive reactions in the 14 control patients.⁵ Given that there are more than 1.5 million users of this isobornyl acrylate–containing glucose sensor across 46 countries,⁷ it requires no stretch of the imagination to understand why investigators refer to isobornyl acrylate allergy as an epidemic, even if only a small percentage of users are sensitized to the device.

The Journey to Discover Isobornyl Acrylate as a Culprit Allergen

Similar to the discoveries of radiography and penicillin, the discovery of isobornyl acrylate as a culprit allergen in a modern glucose sensor was purely accidental. In 2016, a 9-year-old boy with diabetes presented to a Belgian dermatology department with ACD to a glucose sensor.¹ A patch test nurse serendipitously applied isobornyl acrylate—0.01%, 0.05%, and 0.1% in petrolatum—which was not intended to be applied as part of the typical acrylate series. The only positive patch test reactions in this patient were to isobornyl acrylate at all 3 concentrations. This lucky error inspired isobornyl acrylate to be tested at multiple other dermatology departments in Europe in patients with ACD to their glucose sensors, leading to its discovery as a culprit allergen.¹

One challenge facing investigators was obtaining information and materials from the diabetic device industry. Medical device manufacturers are not required to disclose chemicals present in a device on its label.⁸ Therefore, for patients or investigators to determine whether a potential allergen is present in a given device, they must request that information from the manufacturer, which can be a time-consuming and frustrating effort. Luckily, investigators collaborated with one another, and Belgian investigators suggested that Swedish investigators performing chemical analyses on a glucose monitoring device should focus on isobornyl acrylate, which enabled its detection in an extract from the device.⁵

Testing for Isobornyl Acrylate Allergy in Your Clinic

Patients with suspected ACD to a diabetic device—insulin pump or glucose sensor—should be patch tested with isobornyl acrylate, in addition to other previously reported allergens. The vehicle typically is petrolatum, and the commonly tested concentration is 0.1%. Testing with lower concentrations such as 0.01% can result in false-negative reactions,⁹ and testing at higher concentrations such as 0.3% can result in irritant skin reactions.² Isobornyl acrylate 0.1% in petrolatum currently is available from one commercial allergen supplier (Chemotechnique Diagnostics). A positive patch test reaction to isobornyl acrylate 0.1% in petrolatum is shown in the Figure.

Management of Diabetic Device ACD

For patients with diabetic device ACD, there are several strategies that can reduce direct contact between the device and the patient’s skin. Methods that have been tried with varying success to allow patients to continue using their glucose sensors include barrier sprays (eg, Cavilon [3M], Silesse Skin Barrier [ConvaTec]); barrier pads (eg, Compeed [HRA Pharma], Surround skin protectors [Eakin], DuoDERM dressings [ConvaTec], Tegaderm dressings [3M]); and topical corticosteroids, calcineurin inhibitors, and phosphodiesterase 4 inhibitors. Nevertheless, a 2019 Finnish study showed that only 14 of 63 (22%) patients with ACD to their isobornyl acrylate–containing glucose sensor were able to continue using the device, with all 14 requiring use of a barrier agent. Despite using the barrier agent, 13 (93%) of these patients had residual dermatitis.⁶ There also is concern that use of barrier methods might hamper the proper functioning of glucose sensors and related devices.

Patients with known isobornyl acrylate contact allergy also may switch to a different diabetic device. A 2019 German study showed that in 5 patients with isobornyl acrylate ACD, none had reactions to the one particular system that has been shown by gas chromatography–mass spectrometry to not contain isobornyl acrylate.¹⁰ However, as a word of caution, the same device also has been associated with ACD^11,12 but has been resolved by using heat staking during the production process.¹³ As manufacturers update device components, identification of other isobornyl acrylate–free devices may require a degree of trial and error, as neither isobornyl acrylate nor any other potential allergen is listed on device labels.

Final Interpretation

Isobornyl acrylate is not a common sensitizer in general patch test populations but is a recently identified major culprit in ACD to diabetic devices. Patch testing with isobornyl acrylate 0.1% in petrolatum is not necessary in standard screening panels but should be considered in patients with suspected ACD to glucose sensors or insulin pumps. If a patient with ACD wants to continue to experience the convenience provided by a diabetic device, options include using topical steroids or barrier agents and/or changing the brand of the diabetic device, though none of these methods are foolproof. Hopefully, the identification of isobornyl acrylate as a culprit allergen will help to improve the lives of patients who use diabetic devices worldwide.

Each year, the American Contact Dermatitis Society names an Allergen of the Year with the purpose of promoting greater awareness of a key allergen and its impact on patients. Often, the Allergen of the Year is an emerging allergen that may represent an underrecognized or novel cause of allergic contact dermatitis (ACD).In 2020, the American Contact Dermatitis Society chose isobornyl acrylate as the Allergen of the Year.¹ Not only has isobornyl acrylate been implicated in an epidemic of contact allergy to diabetic devices, but it also illustrates the challenges of investigating contact allergy to medical devices in general.

What Is Isobornyl Acrylate?

Isobornyl acrylate, also known as the isobornyl ester of acrylic acid, is a chemical used in glues, adhesives, coatings, sealants, inks, and paints. Similar to other acrylates, such as those involved in gel nail treatments, it is photopolymerizable; that is, when exposed to UV light, it can transform from a liquid monomer into a hard polymer, contributing to its utility as an adhesive. Prior to its recent implication in diabetic device contact allergy, isobornyl acrylate was not thought to be a common skin sensitizer. In a 2013 Dutch study of patients with acrylate allergy, only 1 of 14 patients with a contact allergy to other acrylates had a positive patch test reaction to isobornyl acrylate, which led the authors to conclude that adding it to their acrylate patch test series was not indicated.²

Isobornyl Acrylate in Diabetic Devices

Devices such as glucose monitoring systems and insulin pumps are used by millions of patients with diabetes worldwide. Not only are continuous glucose monitoring devices more convenient than self-monitoring of blood glucose, but they also are associated with a reduction in hemoglobin A_1c levels and lower risk for hypoglycemia.³ However, these devices have been increasingly recognized as a source of irritant contact dermatitis and ACD.

Early cases of contact allergy to isobornyl acrylate in diabetic devices were reported in 1995 when 2 Belgian patients using insulin pumps developed ACD.⁴ The patients had positive patch test reactions to isobornyl acrylate 0.1% in petrolatum and other allergens including acrylates. In addition, patch testing with plastic scrapings from their insulin pumps also was positive, and it was determined that the glue affixing the needle to the plastic had diffused into the plastic. The patients were switched to insulin pumps produced by heat staking instead of glue, and their symptoms resolved. In retrospect, this case series may seem prescient, as it was written 2 decades before isobornyl acrylate became recognized as a widespread cause of ACD in users of diabetic devices. Admittedly, other acrylate components of the glue also were positive on patch testing in these patients, so it was not until much later that the focus turned more exclusively to isobornyl acrylate.⁴

Similar to the insulin pumps in the 1995 Belgian series, diffusion of glue to other parts of modern glucose sensors also appears to cause isobornyl acrylate contact allergy. This theory was supported by a 2017 study from Belgian and Swedish investigators in which gas chromatography–mass spectrometry was used to identify concentrations of isobornyl acrylate in various components of a popular continuous glucose monitoring sensor.⁵ The concentration of isobornyl acrylate was approximately 100-fold higher at the site where the top and bottom plastic components of the sensor were joined as compared to the adhesive patch in contact with the patient’s skin. Therefore, the adhesive patch itself was not the source of the isobornyl acrylate exposure; rather, the isobornyl acrylate diffused into the adhesive patch from the glue used to join the components of the sensor together.⁵ One ramification is that patients with diabetic device contact allergy can have a false-negative patch test result if the adhesive patch is tested by itself, whereas they may react to patch testing with the whole sensor or an acetonic extract thereof.

Frequency of Sensitization to Isobornyl Acrylate

It is difficult to estimate the frequency of sensitization to isobornyl acrylate among users of diabetic devices, in part because those with mild allergy may not seek medical treatment. Nevertheless, there are studies that demonstrate a high prevalence of sensitization among users with suspected allergy. In a 2019 Finnish study of 6567 patients using an isobornyl acrylate–containing glucose sensor, 63 were patch tested for suspected ACD.⁶ Of these 63 patients, 51 (81%) had positive patch test reactions to isobornyl acrylate 0.1% in petrolatum. These findings were consistent with the original 2017 study from Belgium and Sweden, in which 10 of 11 (91%) patients who used an isobornyl acrylate–containing glucose sensor and had suspected contact allergy had positive patch test reactions to isobornyl acrylate 0.1% in petrolatum compared to no positive reactions in the 14 control patients.⁵ Given that there are more than 1.5 million users of this isobornyl acrylate–containing glucose sensor across 46 countries,⁷ it requires no stretch of the imagination to understand why investigators refer to isobornyl acrylate allergy as an epidemic, even if only a small percentage of users are sensitized to the device.

The Journey to Discover Isobornyl Acrylate as a Culprit Allergen

Similar to the discoveries of radiography and penicillin, the discovery of isobornyl acrylate as a culprit allergen in a modern glucose sensor was purely accidental. In 2016, a 9-year-old boy with diabetes presented to a Belgian dermatology department with ACD to a glucose sensor.¹ A patch test nurse serendipitously applied isobornyl acrylate—0.01%, 0.05%, and 0.1% in petrolatum—which was not intended to be applied as part of the typical acrylate series. The only positive patch test reactions in this patient were to isobornyl acrylate at all 3 concentrations. This lucky error inspired isobornyl acrylate to be tested at multiple other dermatology departments in Europe in patients with ACD to their glucose sensors, leading to its discovery as a culprit allergen.¹

One challenge facing investigators was obtaining information and materials from the diabetic device industry. Medical device manufacturers are not required to disclose chemicals present in a device on its label.⁸ Therefore, for patients or investigators to determine whether a potential allergen is present in a given device, they must request that information from the manufacturer, which can be a time-consuming and frustrating effort. Luckily, investigators collaborated with one another, and Belgian investigators suggested that Swedish investigators performing chemical analyses on a glucose monitoring device should focus on isobornyl acrylate, which enabled its detection in an extract from the device.⁵

Testing for Isobornyl Acrylate Allergy in Your Clinic

Patients with suspected ACD to a diabetic device—insulin pump or glucose sensor—should be patch tested with isobornyl acrylate, in addition to other previously reported allergens. The vehicle typically is petrolatum, and the commonly tested concentration is 0.1%. Testing with lower concentrations such as 0.01% can result in false-negative reactions,⁹ and testing at higher concentrations such as 0.3% can result in irritant skin reactions.² Isobornyl acrylate 0.1% in petrolatum currently is available from one commercial allergen supplier (Chemotechnique Diagnostics). A positive patch test reaction to isobornyl acrylate 0.1% in petrolatum is shown in the Figure.

Management of Diabetic Device ACD

For patients with diabetic device ACD, there are several strategies that can reduce direct contact between the device and the patient’s skin. Methods that have been tried with varying success to allow patients to continue using their glucose sensors include barrier sprays (eg, Cavilon [3M], Silesse Skin Barrier [ConvaTec]); barrier pads (eg, Compeed [HRA Pharma], Surround skin protectors [Eakin], DuoDERM dressings [ConvaTec], Tegaderm dressings [3M]); and topical corticosteroids, calcineurin inhibitors, and phosphodiesterase 4 inhibitors. Nevertheless, a 2019 Finnish study showed that only 14 of 63 (22%) patients with ACD to their isobornyl acrylate–containing glucose sensor were able to continue using the device, with all 14 requiring use of a barrier agent. Despite using the barrier agent, 13 (93%) of these patients had residual dermatitis.⁶ There also is concern that use of barrier methods might hamper the proper functioning of glucose sensors and related devices.

Patients with known isobornyl acrylate contact allergy also may switch to a different diabetic device. A 2019 German study showed that in 5 patients with isobornyl acrylate ACD, none had reactions to the one particular system that has been shown by gas chromatography–mass spectrometry to not contain isobornyl acrylate.¹⁰ However, as a word of caution, the same device also has been associated with ACD^11,12 but has been resolved by using heat staking during the production process.¹³ As manufacturers update device components, identification of other isobornyl acrylate–free devices may require a degree of trial and error, as neither isobornyl acrylate nor any other potential allergen is listed on device labels.

Final Interpretation

Isobornyl acrylate is not a common sensitizer in general patch test populations but is a recently identified major culprit in ACD to diabetic devices. Patch testing with isobornyl acrylate 0.1% in petrolatum is not necessary in standard screening panels but should be considered in patients with suspected ACD to glucose sensors or insulin pumps. If a patient with ACD wants to continue to experience the convenience provided by a diabetic device, options include using topical steroids or barrier agents and/or changing the brand of the diabetic device, though none of these methods are foolproof. Hopefully, the identification of isobornyl acrylate as a culprit allergen will help to improve the lives of patients who use diabetic devices worldwide.

Each year, the American Contact Dermatitis Society names an Allergen of the Year with the purpose of promoting greater awareness of a key allergen and its impact on patients. Often, the Allergen of the Year is an emerging allergen that may represent an underrecognized or novel cause of allergic contact dermatitis (ACD).In 2020, the American Contact Dermatitis Society chose isobornyl acrylate as the Allergen of the Year.¹ Not only has isobornyl acrylate been implicated in an epidemic of contact allergy to diabetic devices, but it also illustrates the challenges of investigating contact allergy to medical devices in general.

What Is Isobornyl Acrylate?

Isobornyl acrylate, also known as the isobornyl ester of acrylic acid, is a chemical used in glues, adhesives, coatings, sealants, inks, and paints. Similar to other acrylates, such as those involved in gel nail treatments, it is photopolymerizable; that is, when exposed to UV light, it can transform from a liquid monomer into a hard polymer, contributing to its utility as an adhesive. Prior to its recent implication in diabetic device contact allergy, isobornyl acrylate was not thought to be a common skin sensitizer. In a 2013 Dutch study of patients with acrylate allergy, only 1 of 14 patients with a contact allergy to other acrylates had a positive patch test reaction to isobornyl acrylate, which led the authors to conclude that adding it to their acrylate patch test series was not indicated.²

Isobornyl Acrylate in Diabetic Devices

Devices such as glucose monitoring systems and insulin pumps are used by millions of patients with diabetes worldwide. Not only are continuous glucose monitoring devices more convenient than self-monitoring of blood glucose, but they also are associated with a reduction in hemoglobin A_1c levels and lower risk for hypoglycemia.³ However, these devices have been increasingly recognized as a source of irritant contact dermatitis and ACD.

Early cases of contact allergy to isobornyl acrylate in diabetic devices were reported in 1995 when 2 Belgian patients using insulin pumps developed ACD.⁴ The patients had positive patch test reactions to isobornyl acrylate 0.1% in petrolatum and other allergens including acrylates. In addition, patch testing with plastic scrapings from their insulin pumps also was positive, and it was determined that the glue affixing the needle to the plastic had diffused into the plastic. The patients were switched to insulin pumps produced by heat staking instead of glue, and their symptoms resolved. In retrospect, this case series may seem prescient, as it was written 2 decades before isobornyl acrylate became recognized as a widespread cause of ACD in users of diabetic devices. Admittedly, other acrylate components of the glue also were positive on patch testing in these patients, so it was not until much later that the focus turned more exclusively to isobornyl acrylate.⁴

Similar to the insulin pumps in the 1995 Belgian series, diffusion of glue to other parts of modern glucose sensors also appears to cause isobornyl acrylate contact allergy. This theory was supported by a 2017 study from Belgian and Swedish investigators in which gas chromatography–mass spectrometry was used to identify concentrations of isobornyl acrylate in various components of a popular continuous glucose monitoring sensor.⁵ The concentration of isobornyl acrylate was approximately 100-fold higher at the site where the top and bottom plastic components of the sensor were joined as compared to the adhesive patch in contact with the patient’s skin. Therefore, the adhesive patch itself was not the source of the isobornyl acrylate exposure; rather, the isobornyl acrylate diffused into the adhesive patch from the glue used to join the components of the sensor together.⁵ One ramification is that patients with diabetic device contact allergy can have a false-negative patch test result if the adhesive patch is tested by itself, whereas they may react to patch testing with the whole sensor or an acetonic extract thereof.

Frequency of Sensitization to Isobornyl Acrylate

It is difficult to estimate the frequency of sensitization to isobornyl acrylate among users of diabetic devices, in part because those with mild allergy may not seek medical treatment. Nevertheless, there are studies that demonstrate a high prevalence of sensitization among users with suspected allergy. In a 2019 Finnish study of 6567 patients using an isobornyl acrylate–containing glucose sensor, 63 were patch tested for suspected ACD.⁶ Of these 63 patients, 51 (81%) had positive patch test reactions to isobornyl acrylate 0.1% in petrolatum. These findings were consistent with the original 2017 study from Belgium and Sweden, in which 10 of 11 (91%) patients who used an isobornyl acrylate–containing glucose sensor and had suspected contact allergy had positive patch test reactions to isobornyl acrylate 0.1% in petrolatum compared to no positive reactions in the 14 control patients.⁵ Given that there are more than 1.5 million users of this isobornyl acrylate–containing glucose sensor across 46 countries,⁷ it requires no stretch of the imagination to understand why investigators refer to isobornyl acrylate allergy as an epidemic, even if only a small percentage of users are sensitized to the device.

The Journey to Discover Isobornyl Acrylate as a Culprit Allergen

Similar to the discoveries of radiography and penicillin, the discovery of isobornyl acrylate as a culprit allergen in a modern glucose sensor was purely accidental. In 2016, a 9-year-old boy with diabetes presented to a Belgian dermatology department with ACD to a glucose sensor.¹ A patch test nurse serendipitously applied isobornyl acrylate—0.01%, 0.05%, and 0.1% in petrolatum—which was not intended to be applied as part of the typical acrylate series. The only positive patch test reactions in this patient were to isobornyl acrylate at all 3 concentrations. This lucky error inspired isobornyl acrylate to be tested at multiple other dermatology departments in Europe in patients with ACD to their glucose sensors, leading to its discovery as a culprit allergen.¹

One challenge facing investigators was obtaining information and materials from the diabetic device industry. Medical device manufacturers are not required to disclose chemicals present in a device on its label.⁸ Therefore, for patients or investigators to determine whether a potential allergen is present in a given device, they must request that information from the manufacturer, which can be a time-consuming and frustrating effort. Luckily, investigators collaborated with one another, and Belgian investigators suggested that Swedish investigators performing chemical analyses on a glucose monitoring device should focus on isobornyl acrylate, which enabled its detection in an extract from the device.⁵

Testing for Isobornyl Acrylate Allergy in Your Clinic

Patients with suspected ACD to a diabetic device—insulin pump or glucose sensor—should be patch tested with isobornyl acrylate, in addition to other previously reported allergens. The vehicle typically is petrolatum, and the commonly tested concentration is 0.1%. Testing with lower concentrations such as 0.01% can result in false-negative reactions,⁹ and testing at higher concentrations such as 0.3% can result in irritant skin reactions.² Isobornyl acrylate 0.1% in petrolatum currently is available from one commercial allergen supplier (Chemotechnique Diagnostics). A positive patch test reaction to isobornyl acrylate 0.1% in petrolatum is shown in the Figure.

Management of Diabetic Device ACD

For patients with diabetic device ACD, there are several strategies that can reduce direct contact between the device and the patient’s skin. Methods that have been tried with varying success to allow patients to continue using their glucose sensors include barrier sprays (eg, Cavilon [3M], Silesse Skin Barrier [ConvaTec]); barrier pads (eg, Compeed [HRA Pharma], Surround skin protectors [Eakin], DuoDERM dressings [ConvaTec], Tegaderm dressings [3M]); and topical corticosteroids, calcineurin inhibitors, and phosphodiesterase 4 inhibitors. Nevertheless, a 2019 Finnish study showed that only 14 of 63 (22%) patients with ACD to their isobornyl acrylate–containing glucose sensor were able to continue using the device, with all 14 requiring use of a barrier agent. Despite using the barrier agent, 13 (93%) of these patients had residual dermatitis.⁶ There also is concern that use of barrier methods might hamper the proper functioning of glucose sensors and related devices.

Patients with known isobornyl acrylate contact allergy also may switch to a different diabetic device. A 2019 German study showed that in 5 patients with isobornyl acrylate ACD, none had reactions to the one particular system that has been shown by gas chromatography–mass spectrometry to not contain isobornyl acrylate.¹⁰ However, as a word of caution, the same device also has been associated with ACD^11,12 but has been resolved by using heat staking during the production process.¹³ As manufacturers update device components, identification of other isobornyl acrylate–free devices may require a degree of trial and error, as neither isobornyl acrylate nor any other potential allergen is listed on device labels.

Final Interpretation

Isobornyl acrylate is not a common sensitizer in general patch test populations but is a recently identified major culprit in ACD to diabetic devices. Patch testing with isobornyl acrylate 0.1% in petrolatum is not necessary in standard screening panels but should be considered in patients with suspected ACD to glucose sensors or insulin pumps. If a patient with ACD wants to continue to experience the convenience provided by a diabetic device, options include using topical steroids or barrier agents and/or changing the brand of the diabetic device, though none of these methods are foolproof. Hopefully, the identification of isobornyl acrylate as a culprit allergen will help to improve the lives of patients who use diabetic devices worldwide.

Practice Gap

Anxiety is common in patients undergoing surgery with general anesthesia and may be exacerbated in patients undergoing dermatologic surgery with local anesthesia. Apprehension might be worse for nail surgery patients because the nail unit is highly innervated and vascular. Many patients fear the anesthetic injections, and there often is pain postoperatively. Perioperative anxiety correlates with increased postoperative pain,¹ analgesic use,² and delayed recovery.³ Several alternatives have been proposed to decrease perioperative anxiety, including nonpharmacologic interventions such as using educational videos, personalized music, hand holding, art activities, and virtual reality, as well as pharmacologic interventions such as benzodiazepines. However, these techniques have not been well studied for nail surgery.

The Technique

Patients generally are anxious about nail surgery secondary to the pain associated with the local anesthetic infiltration; hence, it is crucial to decrease anxiety during this initial step. In our practice, we provide patients with a palm-sized stress ball made of closed-cell polyurethane foam rubber before surgery. Patients are then instructed to hold the stress ball with the free hand and squeeze it whenever they feel anxious or when they feel any discomfort related to the procedure (Figure). A variety of balls can be bought for less than $1 each, thus making it a cost-effective option.

Practice Implications

Holding a stress ball has been found to reduce both pain and anxiety in patients undergoing conscious surgery.⁴ Furthermore, squeezing a stress ball perioperatively may increase feelings of empowerment, given that patients have direct control over the object, which in turn may have a positive effect on anxiety and patient satisfaction without interfering with the surgical procedure.⁵ Holding a stress ball is a safe, widely accessible, and inexpensive technique that may aid in decreasing patients’ anxiety related to nail surgery. Nonetheless, controlled clinical trials assessing the efficacy of this method in reducing anxiety related to nail surgery are needed to determine its benefit compared to other methods.

Practice Gap

Anxiety is common in patients undergoing surgery with general anesthesia and may be exacerbated in patients undergoing dermatologic surgery with local anesthesia. Apprehension might be worse for nail surgery patients because the nail unit is highly innervated and vascular. Many patients fear the anesthetic injections, and there often is pain postoperatively. Perioperative anxiety correlates with increased postoperative pain,¹ analgesic use,² and delayed recovery.³ Several alternatives have been proposed to decrease perioperative anxiety, including nonpharmacologic interventions such as using educational videos, personalized music, hand holding, art activities, and virtual reality, as well as pharmacologic interventions such as benzodiazepines. However, these techniques have not been well studied for nail surgery.

The Technique

Patients generally are anxious about nail surgery secondary to the pain associated with the local anesthetic infiltration; hence, it is crucial to decrease anxiety during this initial step. In our practice, we provide patients with a palm-sized stress ball made of closed-cell polyurethane foam rubber before surgery. Patients are then instructed to hold the stress ball with the free hand and squeeze it whenever they feel anxious or when they feel any discomfort related to the procedure (Figure). A variety of balls can be bought for less than $1 each, thus making it a cost-effective option.

Practice Implications

Holding a stress ball has been found to reduce both pain and anxiety in patients undergoing conscious surgery.⁴ Furthermore, squeezing a stress ball perioperatively may increase feelings of empowerment, given that patients have direct control over the object, which in turn may have a positive effect on anxiety and patient satisfaction without interfering with the surgical procedure.⁵ Holding a stress ball is a safe, widely accessible, and inexpensive technique that may aid in decreasing patients’ anxiety related to nail surgery. Nonetheless, controlled clinical trials assessing the efficacy of this method in reducing anxiety related to nail surgery are needed to determine its benefit compared to other methods.

Practice Gap

Anxiety is common in patients undergoing surgery with general anesthesia and may be exacerbated in patients undergoing dermatologic surgery with local anesthesia. Apprehension might be worse for nail surgery patients because the nail unit is highly innervated and vascular. Many patients fear the anesthetic injections, and there often is pain postoperatively. Perioperative anxiety correlates with increased postoperative pain,¹ analgesic use,² and delayed recovery.³ Several alternatives have been proposed to decrease perioperative anxiety, including nonpharmacologic interventions such as using educational videos, personalized music, hand holding, art activities, and virtual reality, as well as pharmacologic interventions such as benzodiazepines. However, these techniques have not been well studied for nail surgery.

The Technique

Patients generally are anxious about nail surgery secondary to the pain associated with the local anesthetic infiltration; hence, it is crucial to decrease anxiety during this initial step. In our practice, we provide patients with a palm-sized stress ball made of closed-cell polyurethane foam rubber before surgery. Patients are then instructed to hold the stress ball with the free hand and squeeze it whenever they feel anxious or when they feel any discomfort related to the procedure (Figure). A variety of balls can be bought for less than $1 each, thus making it a cost-effective option.

Practice Implications

Holding a stress ball has been found to reduce both pain and anxiety in patients undergoing conscious surgery.⁴ Furthermore, squeezing a stress ball perioperatively may increase feelings of empowerment, given that patients have direct control over the object, which in turn may have a positive effect on anxiety and patient satisfaction without interfering with the surgical procedure.⁵ Holding a stress ball is a safe, widely accessible, and inexpensive technique that may aid in decreasing patients’ anxiety related to nail surgery. Nonetheless, controlled clinical trials assessing the efficacy of this method in reducing anxiety related to nail surgery are needed to determine its benefit compared to other methods.

Dermatologic treatment of patients with skin of color offers specific challenges. Studies have reported structural, morphologic, and physiologic distinctions among different ethnic groups,¹ which may account for distinct clinical presentations of skin disease seen in patients with skin of color. Patients with skin of color are at increased risk for specific dermatologic conditions, such as postinflammatory hyperpigmentation, keloid development, and central centrifugal cicatricial alopecia.^2,3 Furthermore, although skin cancer is less prevalent in patients with skin of color, it often presents at a more advanced stage and with a worse prognosis compared to white patients.⁴

Individuals with skin of color make up the majority of the world’s population and a rapidly expanding portion of the US population. By the year 2044, more than half of all Americans are projected to belong to an ethnic group that is currently a minority. By 2060, the population of citizens identifying with 2 or more races will increase by 226%, the Asian population is projected to grow by 128%, the Hispanic population will increase by 115%, and the black population will increase by 42%.⁵ The racial and ethnic composition of the United States is evolving, and dermatologic care must evolve accordingly to address patients’ unique concerns. It is essential for future dermatologists to be knowledgeable about dermatologic conditions presenting in patients of various ethnic backgrounds.

Prior studies have demonstrated the need for increased exposure, education, and training in diseases pertaining to skin of color in US dermatology residency programs.^6-8 The aim of this study was to assess if dermatologists in-training feel that their residency curriculum sufficiently educates them on the needs of patients with skin of color.

Methods

A 10-question anonymous survey was emailed to 109 dermatology residency programs to evaluate the attitudes of dermatology residents about their exposure to patients with skin of color and their skin-of-color curriculum. The study included individuals 18 years or older who were current residents in a dermatology program accredited by the Accreditation Council for Graduate Medical Education. Responses were measured on a 1 to 3 Likert scale, ranging from agree, neutral, and disagree. Data were analyzed using the Fisher exact test, and the statistical significance was set at P<.05.

Results

Forty-three dermatology residents completed the survey. Respondents self-selected their regions, with 8 (19%) from the Northeast (NE), 7 (16%) from the Southeast (SE), 12 (28%) from the Midwest (MW), 8 (19%) from the Southwest (SW), and 8 (18%) from the Northwest (NW)(Table 1). Overall, 31 (72%) respondents agreed that their practice treats a diverse patient population. Respondents who agreed most often were from the NE, SE, and SW. Less than two-thirds of respondents from the MW agreed, and only half of respondents from the NW agreed (Table 2). Although 37% of all respondents agreed that a dedicated multiethnic skin clinic is important for residents, 5 (63%) NE residents disagreed with this statement compared to 5 (42%) MW residents and 5 (63%) NW residents who agreed (P<.005). Overall, 39 (91%) respondents agreed that dedicated lectures on skin conditions in skin of color patients are important to gain competence in treating patients. Only 4 respondents were neutral to this question, 2 (17%) MW residents and 2 (25%) SW residents. When asked if reading textbook chapters on multiethnic skin is important to gain competence, 36 (83%) respondents agreed. Two respondents disagreed, 1 (13%) from the NE and 1 (8%) from the MW. Overall, 23% of respondents agreed that a rotation dedicated to skin of color is important to build competency. There was a significant difference in responses between the NE and MW (P=.032) and between the NE and NW (P=.019). Furthermore, 19 (44%) respondents agreed that having a faculty member or departmental expert is important for residents to gain competence in treating conditions affecting skin of color. Again, there was a significant difference in responses between the NE and MW (P=.003) and between the SE and MW (P=.009).

When asked the number of hours of lecture per month necessary to gain competence in conditions affecting patients with skin of color, 67% agreed that 1 to 5 hours was sufficient (Table 3). There were significant differences in the responses between the NE and SE (P=.024) and the SE and MW (P=.007). Of all respondents, 53% reported 1 to 5 months of clinical training are needed to gain competence in treating conditions affecting patients with skin of color, with significant differences in responses between the NE and MW (P<.001), the NE and SW (P=.019), and the SE and MW (P=.015)(Table 4).

Comment

Responses varied by practicing region. Less ethnically diverse regions, such as the MW and NW, were more likely to agree that dedicated clinics and rotations are important to gain competence compared to more ethnically diverse regions such as the NE, SE, and SW. Overall, more residents reported that dedicated lectures and textbook chapters were important to gain competency compared to dedicated clinics or rotations.

Although interactive lectures and textbook readings are important for obtaining a foundational understanding of dermatologic disease, they cannot substitute for clinical interactions and hands-on experience treating patients with skin of color.⁹ Not only do clinical interactions encourage independent reading and the study of encountered diagnoses, but intercommunication with patients may have a more profound and lasting impact on residents’ education.

Different regions of the United States have varying distributions of patients with skin of color, and dermatology residency program training reflects these disparities.⁶ In areas of less diversity, dermatology residents examine, diagnose, and treat substantially fewer patients with skin of color. The desire for more diverse training supports the prior findings of Nijhawan et al⁶ and is reflected in the responses we received in our study, whereby residents from the less ethnically diversified regions of the MW and NW were more likely to agree that clinics and rotations were necessary for training in preparation to sufficiently address the needs of patients with skin of color.

One way to compensate for the lack of ethnic diversity encountered in areas such as the MW and NW would be to develop educational programs featuring experts on skin of color.⁶ These specialists would not only train dermatology residents in areas of the country currently lacking ethnic diversity but also expand the expertise for treating patients with skin of color. Additionally, dedicated multiethnic skin clinics and externships devoted solely to treating patients with skin of color could be encouraged for residency training.⁶ Finally, community outreach through volunteer clinics may provide residents exposure to patients with skin of color seeking dermatologic care.¹⁰

This study was limited by the small number of respondents, but we were able to extract important trends and data from the collected responses. It is possible that respondents felt strongly about topics involving patients with skin of color, and the results were skewed to reflect individual bias. Additional limitations included not asking respondents for program names and population density (eg, urban, suburban, rural). Future studies should be directed toward analyzing how the diversity of the local population influences training in patients with skin of color, comparing program directors’ perceptions with residents’ perceptions on training in skin of color, and assessing patient perception of residents’ training in skin of color.

Conclusion

In the last decade it has become increasingly apparent that the US population is diversifying and that patients with skin of color will comprise a substantial proportion of the future population,^8,11 which emphasizes the need for dermatology residency programs to ensure that residents receive adequate training and exposure to patients with skin of color as well as the distinct skin diseases seen more commonly in these populations.¹²

Dermatologic treatment of patients with skin of color offers specific challenges. Studies have reported structural, morphologic, and physiologic distinctions among different ethnic groups,¹ which may account for distinct clinical presentations of skin disease seen in patients with skin of color. Patients with skin of color are at increased risk for specific dermatologic conditions, such as postinflammatory hyperpigmentation, keloid development, and central centrifugal cicatricial alopecia.^2,3 Furthermore, although skin cancer is less prevalent in patients with skin of color, it often presents at a more advanced stage and with a worse prognosis compared to white patients.⁴

Individuals with skin of color make up the majority of the world’s population and a rapidly expanding portion of the US population. By the year 2044, more than half of all Americans are projected to belong to an ethnic group that is currently a minority. By 2060, the population of citizens identifying with 2 or more races will increase by 226%, the Asian population is projected to grow by 128%, the Hispanic population will increase by 115%, and the black population will increase by 42%.⁵ The racial and ethnic composition of the United States is evolving, and dermatologic care must evolve accordingly to address patients’ unique concerns. It is essential for future dermatologists to be knowledgeable about dermatologic conditions presenting in patients of various ethnic backgrounds.

Prior studies have demonstrated the need for increased exposure, education, and training in diseases pertaining to skin of color in US dermatology residency programs.^6-8 The aim of this study was to assess if dermatologists in-training feel that their residency curriculum sufficiently educates them on the needs of patients with skin of color.

Methods

A 10-question anonymous survey was emailed to 109 dermatology residency programs to evaluate the attitudes of dermatology residents about their exposure to patients with skin of color and their skin-of-color curriculum. The study included individuals 18 years or older who were current residents in a dermatology program accredited by the Accreditation Council for Graduate Medical Education. Responses were measured on a 1 to 3 Likert scale, ranging from agree, neutral, and disagree. Data were analyzed using the Fisher exact test, and the statistical significance was set at P<.05.

Results

Forty-three dermatology residents completed the survey. Respondents self-selected their regions, with 8 (19%) from the Northeast (NE), 7 (16%) from the Southeast (SE), 12 (28%) from the Midwest (MW), 8 (19%) from the Southwest (SW), and 8 (18%) from the Northwest (NW)(Table 1). Overall, 31 (72%) respondents agreed that their practice treats a diverse patient population. Respondents who agreed most often were from the NE, SE, and SW. Less than two-thirds of respondents from the MW agreed, and only half of respondents from the NW agreed (Table 2). Although 37% of all respondents agreed that a dedicated multiethnic skin clinic is important for residents, 5 (63%) NE residents disagreed with this statement compared to 5 (42%) MW residents and 5 (63%) NW residents who agreed (P<.005). Overall, 39 (91%) respondents agreed that dedicated lectures on skin conditions in skin of color patients are important to gain competence in treating patients. Only 4 respondents were neutral to this question, 2 (17%) MW residents and 2 (25%) SW residents. When asked if reading textbook chapters on multiethnic skin is important to gain competence, 36 (83%) respondents agreed. Two respondents disagreed, 1 (13%) from the NE and 1 (8%) from the MW. Overall, 23% of respondents agreed that a rotation dedicated to skin of color is important to build competency. There was a significant difference in responses between the NE and MW (P=.032) and between the NE and NW (P=.019). Furthermore, 19 (44%) respondents agreed that having a faculty member or departmental expert is important for residents to gain competence in treating conditions affecting skin of color. Again, there was a significant difference in responses between the NE and MW (P=.003) and between the SE and MW (P=.009).

When asked the number of hours of lecture per month necessary to gain competence in conditions affecting patients with skin of color, 67% agreed that 1 to 5 hours was sufficient (Table 3). There were significant differences in the responses between the NE and SE (P=.024) and the SE and MW (P=.007). Of all respondents, 53% reported 1 to 5 months of clinical training are needed to gain competence in treating conditions affecting patients with skin of color, with significant differences in responses between the NE and MW (P<.001), the NE and SW (P=.019), and the SE and MW (P=.015)(Table 4).

Comment

Responses varied by practicing region. Less ethnically diverse regions, such as the MW and NW, were more likely to agree that dedicated clinics and rotations are important to gain competence compared to more ethnically diverse regions such as the NE, SE, and SW. Overall, more residents reported that dedicated lectures and textbook chapters were important to gain competency compared to dedicated clinics or rotations.

Although interactive lectures and textbook readings are important for obtaining a foundational understanding of dermatologic disease, they cannot substitute for clinical interactions and hands-on experience treating patients with skin of color.⁹ Not only do clinical interactions encourage independent reading and the study of encountered diagnoses, but intercommunication with patients may have a more profound and lasting impact on residents’ education.

Different regions of the United States have varying distributions of patients with skin of color, and dermatology residency program training reflects these disparities.⁶ In areas of less diversity, dermatology residents examine, diagnose, and treat substantially fewer patients with skin of color. The desire for more diverse training supports the prior findings of Nijhawan et al⁶ and is reflected in the responses we received in our study, whereby residents from the less ethnically diversified regions of the MW and NW were more likely to agree that clinics and rotations were necessary for training in preparation to sufficiently address the needs of patients with skin of color.

One way to compensate for the lack of ethnic diversity encountered in areas such as the MW and NW would be to develop educational programs featuring experts on skin of color.⁶ These specialists would not only train dermatology residents in areas of the country currently lacking ethnic diversity but also expand the expertise for treating patients with skin of color. Additionally, dedicated multiethnic skin clinics and externships devoted solely to treating patients with skin of color could be encouraged for residency training.⁶ Finally, community outreach through volunteer clinics may provide residents exposure to patients with skin of color seeking dermatologic care.¹⁰

This study was limited by the small number of respondents, but we were able to extract important trends and data from the collected responses. It is possible that respondents felt strongly about topics involving patients with skin of color, and the results were skewed to reflect individual bias. Additional limitations included not asking respondents for program names and population density (eg, urban, suburban, rural). Future studies should be directed toward analyzing how the diversity of the local population influences training in patients with skin of color, comparing program directors’ perceptions with residents’ perceptions on training in skin of color, and assessing patient perception of residents’ training in skin of color.

Conclusion

In the last decade it has become increasingly apparent that the US population is diversifying and that patients with skin of color will comprise a substantial proportion of the future population,^8,11 which emphasizes the need for dermatology residency programs to ensure that residents receive adequate training and exposure to patients with skin of color as well as the distinct skin diseases seen more commonly in these populations.¹²

Dermatologic treatment of patients with skin of color offers specific challenges. Studies have reported structural, morphologic, and physiologic distinctions among different ethnic groups,¹ which may account for distinct clinical presentations of skin disease seen in patients with skin of color. Patients with skin of color are at increased risk for specific dermatologic conditions, such as postinflammatory hyperpigmentation, keloid development, and central centrifugal cicatricial alopecia.^2,3 Furthermore, although skin cancer is less prevalent in patients with skin of color, it often presents at a more advanced stage and with a worse prognosis compared to white patients.⁴

Individuals with skin of color make up the majority of the world’s population and a rapidly expanding portion of the US population. By the year 2044, more than half of all Americans are projected to belong to an ethnic group that is currently a minority. By 2060, the population of citizens identifying with 2 or more races will increase by 226%, the Asian population is projected to grow by 128%, the Hispanic population will increase by 115%, and the black population will increase by 42%.⁵ The racial and ethnic composition of the United States is evolving, and dermatologic care must evolve accordingly to address patients’ unique concerns. It is essential for future dermatologists to be knowledgeable about dermatologic conditions presenting in patients of various ethnic backgrounds.

Prior studies have demonstrated the need for increased exposure, education, and training in diseases pertaining to skin of color in US dermatology residency programs.^6-8 The aim of this study was to assess if dermatologists in-training feel that their residency curriculum sufficiently educates them on the needs of patients with skin of color.

Methods

A 10-question anonymous survey was emailed to 109 dermatology residency programs to evaluate the attitudes of dermatology residents about their exposure to patients with skin of color and their skin-of-color curriculum. The study included individuals 18 years or older who were current residents in a dermatology program accredited by the Accreditation Council for Graduate Medical Education. Responses were measured on a 1 to 3 Likert scale, ranging from agree, neutral, and disagree. Data were analyzed using the Fisher exact test, and the statistical significance was set at P<.05.

Results

Forty-three dermatology residents completed the survey. Respondents self-selected their regions, with 8 (19%) from the Northeast (NE), 7 (16%) from the Southeast (SE), 12 (28%) from the Midwest (MW), 8 (19%) from the Southwest (SW), and 8 (18%) from the Northwest (NW)(Table 1). Overall, 31 (72%) respondents agreed that their practice treats a diverse patient population. Respondents who agreed most often were from the NE, SE, and SW. Less than two-thirds of respondents from the MW agreed, and only half of respondents from the NW agreed (Table 2). Although 37% of all respondents agreed that a dedicated multiethnic skin clinic is important for residents, 5 (63%) NE residents disagreed with this statement compared to 5 (42%) MW residents and 5 (63%) NW residents who agreed (P<.005). Overall, 39 (91%) respondents agreed that dedicated lectures on skin conditions in skin of color patients are important to gain competence in treating patients. Only 4 respondents were neutral to this question, 2 (17%) MW residents and 2 (25%) SW residents. When asked if reading textbook chapters on multiethnic skin is important to gain competence, 36 (83%) respondents agreed. Two respondents disagreed, 1 (13%) from the NE and 1 (8%) from the MW. Overall, 23% of respondents agreed that a rotation dedicated to skin of color is important to build competency. There was a significant difference in responses between the NE and MW (P=.032) and between the NE and NW (P=.019). Furthermore, 19 (44%) respondents agreed that having a faculty member or departmental expert is important for residents to gain competence in treating conditions affecting skin of color. Again, there was a significant difference in responses between the NE and MW (P=.003) and between the SE and MW (P=.009).

When asked the number of hours of lecture per month necessary to gain competence in conditions affecting patients with skin of color, 67% agreed that 1 to 5 hours was sufficient (Table 3). There were significant differences in the responses between the NE and SE (P=.024) and the SE and MW (P=.007). Of all respondents, 53% reported 1 to 5 months of clinical training are needed to gain competence in treating conditions affecting patients with skin of color, with significant differences in responses between the NE and MW (P<.001), the NE and SW (P=.019), and the SE and MW (P=.015)(Table 4).

Comment

Responses varied by practicing region. Less ethnically diverse regions, such as the MW and NW, were more likely to agree that dedicated clinics and rotations are important to gain competence compared to more ethnically diverse regions such as the NE, SE, and SW. Overall, more residents reported that dedicated lectures and textbook chapters were important to gain competency compared to dedicated clinics or rotations.

Although interactive lectures and textbook readings are important for obtaining a foundational understanding of dermatologic disease, they cannot substitute for clinical interactions and hands-on experience treating patients with skin of color.⁹ Not only do clinical interactions encourage independent reading and the study of encountered diagnoses, but intercommunication with patients may have a more profound and lasting impact on residents’ education.

Different regions of the United States have varying distributions of patients with skin of color, and dermatology residency program training reflects these disparities.⁶ In areas of less diversity, dermatology residents examine, diagnose, and treat substantially fewer patients with skin of color. The desire for more diverse training supports the prior findings of Nijhawan et al⁶ and is reflected in the responses we received in our study, whereby residents from the less ethnically diversified regions of the MW and NW were more likely to agree that clinics and rotations were necessary for training in preparation to sufficiently address the needs of patients with skin of color.

One way to compensate for the lack of ethnic diversity encountered in areas such as the MW and NW would be to develop educational programs featuring experts on skin of color.⁶ These specialists would not only train dermatology residents in areas of the country currently lacking ethnic diversity but also expand the expertise for treating patients with skin of color. Additionally, dedicated multiethnic skin clinics and externships devoted solely to treating patients with skin of color could be encouraged for residency training.⁶ Finally, community outreach through volunteer clinics may provide residents exposure to patients with skin of color seeking dermatologic care.¹⁰

This study was limited by the small number of respondents, but we were able to extract important trends and data from the collected responses. It is possible that respondents felt strongly about topics involving patients with skin of color, and the results were skewed to reflect individual bias. Additional limitations included not asking respondents for program names and population density (eg, urban, suburban, rural). Future studies should be directed toward analyzing how the diversity of the local population influences training in patients with skin of color, comparing program directors’ perceptions with residents’ perceptions on training in skin of color, and assessing patient perception of residents’ training in skin of color.

Conclusion

In the last decade it has become increasingly apparent that the US population is diversifying and that patients with skin of color will comprise a substantial proportion of the future population,^8,11 which emphasizes the need for dermatology residency programs to ensure that residents receive adequate training and exposure to patients with skin of color as well as the distinct skin diseases seen more commonly in these populations.¹²

Case Report

A 37-year-old woman presented to the dermatology clinic with an itchy rash involving the right hand. The rash had been present for 10 days but had become increasingly pruritic and vesicular over the last 5 days. She denied new exposures or other household members with similar symptoms. The patient reported that she had purchased a 4-toed, white-bellied African pygmy hedgehog (Atelerix albiventris) approximately 4 months prior. Upon questioning, she stated that she handled the hedgehog a couple of times a week and always washed her hands with soap and water immediately after. The patient’s medical and personal history were otherwise unremarkable.

Review of systems, including fevers, chills, and night sweats, was negative. Clinical examination revealed erythema with overlying vesicles and pustules on the right radial palm, radial dorsal hand, and interdigital web space of the first and second digit (Figure 1). The eruption was actively discharging serous exudate. No other lesions were present.

Comment

Tinea manuum is a dermatophytic epidermal infection of the hand. The most common causative organisms are Trichophyton rubrum, T mentagrophytes, and Epidermophyton floccosum. Infection can be acquired from contact with an infected person or animal, fomites, soil, or autoinoculation. Tinea manuum often is associated with tinea pedis. The hand that is used to excoriate the pruritic feet becomes infected, resulting in the classic two feet–one hand syndrome, which this patient did not have.¹

Dermatophytes colonize keratin-containing tissues—skin, hair, and nails—utilizing the keratin for nutrients, and they do not invade living tissue in immunocompetent hosts. Dermatophytes cause clinical disease from an allergic host response to fungal antigens or their metabolic products.¹ Tinea incognito results from the use of corticosteroids to treat a cutaneous fungal infection. The immunomodulatory effects of corticosteroids alter the appearance of the lesion. Hallmark signs and symptoms of a tinea infection, including scale, prominent border, erythema, and pruritus, can be reduced with corticosteroid use, giving the false impression that the lesion is resolving.^2,3 

The diagnosis of tinea manuum can be made clinically and often is supported with the findings of a KOH preparation. Scraping from an active scaling border generally provides the best results for obtaining fungal elements. For vesiculobullous lesions, the roof of a vesicle can provide an adequate specimen. Fungal culture and specific dermatophyte testing mediums can be used as confirmatory tests or allow for speciation, which help establish the diagnosis.¹

Trichophyton mentagrophytes is a species complex—a group of closely related organisms that share morphologic appearance to the point that boundaries between them often are unclear. It can be identified by gross and microscopic morphology; however, variants of T mentagrophytes (eg, Trichophyton interdigitale, Trichophyton erinacei) require a confirmatory test or molecular analysis to be correctly identified.^4-6 The laboratory used at our facility does not routinely attempt to identify the variant due to of lack of clinical significance.^7,8

Anthropophilic fungi such as T rubrum, E floccosum, and T interdigitale generally do not cause a robust immunologic reaction. Infection usually is chronic in nature, though cases of pustular and vesicular tinea have been described.^9,10Trichophyton erinacei and T mentagrophytes are zoophilic dermatophytes that cause an acute host response and are more likely to present with vesiculobullous lesions. Trichophyton erinacei is the most common fungal pathogen associated with A albiventris and has been isolated from its epidermal mites and quills,^11,12 which likely facilitates interspecies transmission and compromises the cutaneous barrier of human hosts when the hedgehog is handled.

Atelerix albiventris is the most common domesticated hedgehog in the United States. These mild-mannered, nocturnal insectivores are unique, low-maintenance pets that have recently gained popularity. They are notable for their propensity to curl into a ball when frightened (Figure 5). The spines are not barbed and do not detach, as those of a porcupine do, but are still capable of piercing the skin. Atelerix albiventris is known to cause zoonotic dermatosis in humans and should be handled with gloves.¹³ Performing a KOH preparation early in the diagnostic workup can help initiate antifungal therapy, as results of fungal culture can take several weeks.

Conclusion

This case illustrates the importance of close follow-up of skin lesions that only partially respond to initial treatment and maintaining a high index of suspicion as exotic pets become popular.

Case Report

A 37-year-old woman presented to the dermatology clinic with an itchy rash involving the right hand. The rash had been present for 10 days but had become increasingly pruritic and vesicular over the last 5 days. She denied new exposures or other household members with similar symptoms. The patient reported that she had purchased a 4-toed, white-bellied African pygmy hedgehog (Atelerix albiventris) approximately 4 months prior. Upon questioning, she stated that she handled the hedgehog a couple of times a week and always washed her hands with soap and water immediately after. The patient’s medical and personal history were otherwise unremarkable.

Review of systems, including fevers, chills, and night sweats, was negative. Clinical examination revealed erythema with overlying vesicles and pustules on the right radial palm, radial dorsal hand, and interdigital web space of the first and second digit (Figure 1). The eruption was actively discharging serous exudate. No other lesions were present.

Comment

Tinea manuum is a dermatophytic epidermal infection of the hand. The most common causative organisms are Trichophyton rubrum, T mentagrophytes, and Epidermophyton floccosum. Infection can be acquired from contact with an infected person or animal, fomites, soil, or autoinoculation. Tinea manuum often is associated with tinea pedis. The hand that is used to excoriate the pruritic feet becomes infected, resulting in the classic two feet–one hand syndrome, which this patient did not have.¹

Dermatophytes colonize keratin-containing tissues—skin, hair, and nails—utilizing the keratin for nutrients, and they do not invade living tissue in immunocompetent hosts. Dermatophytes cause clinical disease from an allergic host response to fungal antigens or their metabolic products.¹ Tinea incognito results from the use of corticosteroids to treat a cutaneous fungal infection. The immunomodulatory effects of corticosteroids alter the appearance of the lesion. Hallmark signs and symptoms of a tinea infection, including scale, prominent border, erythema, and pruritus, can be reduced with corticosteroid use, giving the false impression that the lesion is resolving.^2,3 

The diagnosis of tinea manuum can be made clinically and often is supported with the findings of a KOH preparation. Scraping from an active scaling border generally provides the best results for obtaining fungal elements. For vesiculobullous lesions, the roof of a vesicle can provide an adequate specimen. Fungal culture and specific dermatophyte testing mediums can be used as confirmatory tests or allow for speciation, which help establish the diagnosis.¹

Trichophyton mentagrophytes is a species complex—a group of closely related organisms that share morphologic appearance to the point that boundaries between them often are unclear. It can be identified by gross and microscopic morphology; however, variants of T mentagrophytes (eg, Trichophyton interdigitale, Trichophyton erinacei) require a confirmatory test or molecular analysis to be correctly identified.^4-6 The laboratory used at our facility does not routinely attempt to identify the variant due to of lack of clinical significance.^7,8

Anthropophilic fungi such as T rubrum, E floccosum, and T interdigitale generally do not cause a robust immunologic reaction. Infection usually is chronic in nature, though cases of pustular and vesicular tinea have been described.^9,10Trichophyton erinacei and T mentagrophytes are zoophilic dermatophytes that cause an acute host response and are more likely to present with vesiculobullous lesions. Trichophyton erinacei is the most common fungal pathogen associated with A albiventris and has been isolated from its epidermal mites and quills,^11,12 which likely facilitates interspecies transmission and compromises the cutaneous barrier of human hosts when the hedgehog is handled.

Atelerix albiventris is the most common domesticated hedgehog in the United States. These mild-mannered, nocturnal insectivores are unique, low-maintenance pets that have recently gained popularity. They are notable for their propensity to curl into a ball when frightened (Figure 5). The spines are not barbed and do not detach, as those of a porcupine do, but are still capable of piercing the skin. Atelerix albiventris is known to cause zoonotic dermatosis in humans and should be handled with gloves.¹³ Performing a KOH preparation early in the diagnostic workup can help initiate antifungal therapy, as results of fungal culture can take several weeks.

Conclusion

This case illustrates the importance of close follow-up of skin lesions that only partially respond to initial treatment and maintaining a high index of suspicion as exotic pets become popular.

Case Report

A 37-year-old woman presented to the dermatology clinic with an itchy rash involving the right hand. The rash had been present for 10 days but had become increasingly pruritic and vesicular over the last 5 days. She denied new exposures or other household members with similar symptoms. The patient reported that she had purchased a 4-toed, white-bellied African pygmy hedgehog (Atelerix albiventris) approximately 4 months prior. Upon questioning, she stated that she handled the hedgehog a couple of times a week and always washed her hands with soap and water immediately after. The patient’s medical and personal history were otherwise unremarkable.

Review of systems, including fevers, chills, and night sweats, was negative. Clinical examination revealed erythema with overlying vesicles and pustules on the right radial palm, radial dorsal hand, and interdigital web space of the first and second digit (Figure 1). The eruption was actively discharging serous exudate. No other lesions were present.

Comment

Tinea manuum is a dermatophytic epidermal infection of the hand. The most common causative organisms are Trichophyton rubrum, T mentagrophytes, and Epidermophyton floccosum. Infection can be acquired from contact with an infected person or animal, fomites, soil, or autoinoculation. Tinea manuum often is associated with tinea pedis. The hand that is used to excoriate the pruritic feet becomes infected, resulting in the classic two feet–one hand syndrome, which this patient did not have.¹

Dermatophytes colonize keratin-containing tissues—skin, hair, and nails—utilizing the keratin for nutrients, and they do not invade living tissue in immunocompetent hosts. Dermatophytes cause clinical disease from an allergic host response to fungal antigens or their metabolic products.¹ Tinea incognito results from the use of corticosteroids to treat a cutaneous fungal infection. The immunomodulatory effects of corticosteroids alter the appearance of the lesion. Hallmark signs and symptoms of a tinea infection, including scale, prominent border, erythema, and pruritus, can be reduced with corticosteroid use, giving the false impression that the lesion is resolving.^2,3 

The diagnosis of tinea manuum can be made clinically and often is supported with the findings of a KOH preparation. Scraping from an active scaling border generally provides the best results for obtaining fungal elements. For vesiculobullous lesions, the roof of a vesicle can provide an adequate specimen. Fungal culture and specific dermatophyte testing mediums can be used as confirmatory tests or allow for speciation, which help establish the diagnosis.¹

Trichophyton mentagrophytes is a species complex—a group of closely related organisms that share morphologic appearance to the point that boundaries between them often are unclear. It can be identified by gross and microscopic morphology; however, variants of T mentagrophytes (eg, Trichophyton interdigitale, Trichophyton erinacei) require a confirmatory test or molecular analysis to be correctly identified.^4-6 The laboratory used at our facility does not routinely attempt to identify the variant due to of lack of clinical significance.^7,8

Anthropophilic fungi such as T rubrum, E floccosum, and T interdigitale generally do not cause a robust immunologic reaction. Infection usually is chronic in nature, though cases of pustular and vesicular tinea have been described.^9,10Trichophyton erinacei and T mentagrophytes are zoophilic dermatophytes that cause an acute host response and are more likely to present with vesiculobullous lesions. Trichophyton erinacei is the most common fungal pathogen associated with A albiventris and has been isolated from its epidermal mites and quills,^11,12 which likely facilitates interspecies transmission and compromises the cutaneous barrier of human hosts when the hedgehog is handled.

Atelerix albiventris is the most common domesticated hedgehog in the United States. These mild-mannered, nocturnal insectivores are unique, low-maintenance pets that have recently gained popularity. They are notable for their propensity to curl into a ball when frightened (Figure 5). The spines are not barbed and do not detach, as those of a porcupine do, but are still capable of piercing the skin. Atelerix albiventris is known to cause zoonotic dermatosis in humans and should be handled with gloves.¹³ Performing a KOH preparation early in the diagnostic workup can help initiate antifungal therapy, as results of fungal culture can take several weeks.

Conclusion

This case illustrates the importance of close follow-up of skin lesions that only partially respond to initial treatment and maintaining a high index of suspicion as exotic pets become popular.