Contact Dermatitis

No time of the year is more exciting than the unveiling of the American Contact Dermatitis Society Allergen of the Year. Sometimes the selected allergen represents a completely novel cause of allergic contact dermatitis (ACD) with an unpronounceable chemical name. Not this time! The 2022 Allergen of the Year is likely to be lurking in your kitchen drawer at this very moment, as this year aluminum was chosen for this most prestigious honor.¹ But do not throw out your aluminum foil just yet—aluminum allergy tends to be confined to specific scenarios. In this article, we highlight the growing recognition of aluminum contact allergy, particularly in the pediatric population, focusing on distinct presentations of aluminum ACD, unique sources of exposure, and nuances of patch testing to this metal.

Aluminum Is All Around Us

As the third most common element in the Earth’s crust, aluminum can be found quite literally everywhere.¹ However, aluminum rarely is found in its pure elemental form; instead, it reacts with other elements around it, most commonly oxygen, to form aluminum-containing compounds. Known for their stability and safety, aluminum and its salts are incorporated in myriad products ranging from electronic equipment to foods and their packaging, medications, cosmetics, orthopedic and dental implants, and even tattoos. Aluminum also is found in the air and water supply and may even be encountered in certain workplaces, such as aircraft and machine industries. As such, contact with aluminum is all but certain in modern life.

The use of aluminum in consumer products is widely accepted as safe by public health agencies in the United States.² Although there has been public concern that aluminum could be linked to development of breast cancer or Alzheimer disease, there is no clear evidence that these conditions are associated with routine aluminum exposure through ingestion or consumer products.^3-5

Aluminum Contact Allergy

In part because of its ubiquity and in part because of the stability of aluminum-containing compounds, it was long thought that aluminum was nonallergenic. Contact allergy to elemental aluminum is rare; on the other hand, aluminum salts (the forms we are likely to encounter in daily life) are now recognized in the field of contact dermatitis as allergens of significance, particularly in the pediatric population.^1,6

First reported as a possible occupational allergen in 1944,⁷ aluminum allergy came to prominence in the 1990s in association with vaccines. Aluminum is included in some vaccines as an adjuvant that bolsters the immune response⁸; the eTable lists currently available aluminum-containing vaccines in the United States; of note, none of the COVID-19 vaccines approved in the United States or Europe contain aluminum.¹¹ Although the use of aluminum in vaccines is considered to be safe by the US Food and Drug Administration and Centers for Disease Control and Prevention,^12,13 a small number of children become sensitized to aluminum through vaccines and may develop persistent pruritic subcutaneous nodules (also known as vaccination granulomas) at the injection site; however, the incidence of this adverse effect was less than 1% in large studies including as many as 76,000 children, suggesting that it is relatively rare.^14,15 Upon patch testing, aluminum allergy has been detected in 77% to 95% of such cases.¹⁴ There is wide variation in the onset of the nodules ranging from weeks to years following vaccination.¹⁵ Due to pruritus, the examination may reveal accompanying excoriations, hyperpigmentation, and sometimes hypertrichosis at the injection site. Aluminum allergy related to vaccination also can manifest with widespread eruptions representing systemic contact dermatitis.¹⁶

Along with vaccines, the second major source of aluminum sensitization is allergen-specific immunotherapies administered by allergists/immunologists, many of which contain aluminum hydroxide.^17,18

On the consumer product front, antiperspirants are the most common source of cutaneous exposure to aluminum. Aluminum complexes react with electrolytes in sweat to form plugs in eccrine ducts, thereby preventing sweat excretion.⁶ Allergic contact dermatitis to these products presents with axillary-vault dermatitis. There also have been reports of ACD to aluminum in sunscreen and toothpaste, with the latter implicated in causing systemic ACD.^19,20

Prevalence of Sensitization to Aluminum

There have been a few large-scale studies evaluating rates of sensitization to aluminum in general patch-test patient populations; additionally, because of the complexities of testing this metal, investigators have utilized differing formulations for patch testing. A recent Swedish study found that 0.9% of 5448 adults and 5.1% of 196 children showed positive reactions to aluminum chloride hexahydrate (ACH) 10% in petrolatum and/or aluminum lactate 12% in petrolatum.²¹ Notably, there was a significant association between aluminum allergy and history of atopy for both adults (P=.0056) and children (P=.046), which remains to be further explored. A systematic review and meta-analysis found comparable rates of aluminum allergy in 0.4% of adults and 5.6% of children without vaccine granulomas who were tested.²² With this evidence in mind, it has been recommended by contact dermatitis experts that aluminum be included in pediatric baseline patch test series and also investigated for potential inclusion in baseline series for adults.¹

Differential Diagnosis of Aluminum ACD

The differential diagnosis for subcutaneous nodules following vaccination is broad and includes various forms of panniculitis, sarcoidosis, foreign body reactions, vascular malformations, infections, and malignancies.^23-25 The diagnosis may be obscured in cases with delayed onset. Biopsy is not mandatory to establish the diagnosis; although variable histopathologic findings have been reported, a common feature is histiocytes with abundant granular cytoplasm.²⁶ It may be possible to demonstrate the presence of aluminum particles in tissue using electron microscopy and X-ray microanalysis.

For those patients who present with axillary-vault dermatitis, the differential includes ACD to more common allergens in antiperspirants (eg, fragrance), as well as other axillary dermatoses including inverse psoriasis, erythrasma, Hailey-Hailey disease, and various forms of intertrigo. Dermatitis localized to the axillary rim suggests textile allergy.

Patch Testing to Aluminum

Due to its physicochemical properties, patch testing for aluminum allergy is complicated, and historically there has been a lack of consensus on the ideal test formulation.^1,27,28 At this time, it appears that the most sensitive formulation for patch testing to aluminum is ACH 10% in petrolatum.¹ Some contact dermatitis experts recommend that children younger than 8 years should be tested with ACH 2% in petrolatum to minimize the risk of extreme patch test reactions.^29,30 In some patients sensitized to aluminum, the use of aluminum patch test chambers has been noted to produce false-positive reactions, taking the form of multiple ring-shaped reactions to the chambers themselves or reactions to certain allergens whose chemical properties cause corrosion of the aluminum within the chambers.^31-33 Therefore, when testing for suspected aluminum allergy, plastic chambers should be used; given the higher prevalence of aluminum allergy in children, some clinics routinely use plastic chambers for all pediatric patch testing.³⁴ Importantly, elemental aluminum, including empty aluminum test chambers or aluminum foil, alone is not sufficient for patch testing as it lacks sensitivity.¹ Additionally, nearly 20% of positive tests will be missed if a day 7 reading is not performed, making delayed reading a must in cases with high suspicion for aluminum allergy.²¹

Management of Aluminum Allergy

The development of pruritic subcutaneous nodules is uncomfortable for children and their guardians alike and may be associated with prolonged symptoms that negatively impact quality of life^35,36; nonetheless, expert authorities have determined that the preventive benefits of childhood vaccination far outweigh any risk posed by the presence of aluminum in vaccines.^12,13,37 Because aluminum-free formulations may not be available for all vaccines, it is essential to educate patients and families who may be at risk for developing vaccine hesitancy or avoidance.^35,36,38 Given the hypothesis that epidermal dendritic cells mediate aluminum sensitization, it has been proposed that vaccine administration via deep intramuscular rather than subcutaneous injection may mitigate the risk, but more evidence is needed to support this approach.^39,40 The good news is that the nodules tend to fade with age, with a median time to resolution of 18 to 49 months.¹⁴ In addition, patients may experience loss of sensitization to aluminum over time⁴¹; in one study, 77% of 241 children lost patch test reactivity when retested 5 to 9 years later.⁴² The exact reason for this diminishment of reactivity is not well understood. Adjunctive treatments to relieve symptoms of vaccine granulomas include topical and intralesional corticosteroids and antihistamines.

For patients reacting to aluminum in antiperspirants, there are many aluminum-free formulations on the market as well as recipes for homemade antiperspirants.⁶ On a case-by-case basis, patients may need to avoid aluminum-containing medications, permanent tattoos, and orthopedic or dental implants. To the best of our knowledge, there is no evidence suggesting a need to avoid aluminum in foods and their containers in routine daily life; although some patients report exacerbations of their symptoms associated with food-related aluminum exposures (eg, canned food, dried fruit) and improvement with dietary modification, further investigation is needed to confirm the relevance of these sources of contact.^36,38 For patients who require allergen-specific immunotherapy, aluminum-free allergen extracts are available.⁶

Final Interpretation

Exposure to aluminum is ubiquitous; although relatively uncommon, awareness of the potential for ACD to aluminum is increasingly important, particularly in children. Given the prevalence of aluminum contact allergy, it has been recommended by contact dermatitis experts for inclusion in baseline pediatric patch test series.¹ Although it is a complex issue, the development of ACD in a small proportion of children exposed to aluminum in vaccines does not outweigh the benefit of vaccination for almost all children. When conducting patch testing to aluminum, studies support testing to ACH 10% in petrolatum for adults, and consider reducing the concentration to ACH 2% for children.

Acknowledgment—The authors thank Ian Fritz, MD (South Portland, Maine), for his critical input during preparation of this article.

No time of the year is more exciting than the unveiling of the American Contact Dermatitis Society Allergen of the Year. Sometimes the selected allergen represents a completely novel cause of allergic contact dermatitis (ACD) with an unpronounceable chemical name. Not this time! The 2022 Allergen of the Year is likely to be lurking in your kitchen drawer at this very moment, as this year aluminum was chosen for this most prestigious honor.¹ But do not throw out your aluminum foil just yet—aluminum allergy tends to be confined to specific scenarios. In this article, we highlight the growing recognition of aluminum contact allergy, particularly in the pediatric population, focusing on distinct presentations of aluminum ACD, unique sources of exposure, and nuances of patch testing to this metal.

Aluminum Is All Around Us

As the third most common element in the Earth’s crust, aluminum can be found quite literally everywhere.¹ However, aluminum rarely is found in its pure elemental form; instead, it reacts with other elements around it, most commonly oxygen, to form aluminum-containing compounds. Known for their stability and safety, aluminum and its salts are incorporated in myriad products ranging from electronic equipment to foods and their packaging, medications, cosmetics, orthopedic and dental implants, and even tattoos. Aluminum also is found in the air and water supply and may even be encountered in certain workplaces, such as aircraft and machine industries. As such, contact with aluminum is all but certain in modern life.

The use of aluminum in consumer products is widely accepted as safe by public health agencies in the United States.² Although there has been public concern that aluminum could be linked to development of breast cancer or Alzheimer disease, there is no clear evidence that these conditions are associated with routine aluminum exposure through ingestion or consumer products.^3-5

Aluminum Contact Allergy

In part because of its ubiquity and in part because of the stability of aluminum-containing compounds, it was long thought that aluminum was nonallergenic. Contact allergy to elemental aluminum is rare; on the other hand, aluminum salts (the forms we are likely to encounter in daily life) are now recognized in the field of contact dermatitis as allergens of significance, particularly in the pediatric population.^1,6

First reported as a possible occupational allergen in 1944,⁷ aluminum allergy came to prominence in the 1990s in association with vaccines. Aluminum is included in some vaccines as an adjuvant that bolsters the immune response⁸; the eTable lists currently available aluminum-containing vaccines in the United States; of note, none of the COVID-19 vaccines approved in the United States or Europe contain aluminum.¹¹ Although the use of aluminum in vaccines is considered to be safe by the US Food and Drug Administration and Centers for Disease Control and Prevention,^12,13 a small number of children become sensitized to aluminum through vaccines and may develop persistent pruritic subcutaneous nodules (also known as vaccination granulomas) at the injection site; however, the incidence of this adverse effect was less than 1% in large studies including as many as 76,000 children, suggesting that it is relatively rare.^14,15 Upon patch testing, aluminum allergy has been detected in 77% to 95% of such cases.¹⁴ There is wide variation in the onset of the nodules ranging from weeks to years following vaccination.¹⁵ Due to pruritus, the examination may reveal accompanying excoriations, hyperpigmentation, and sometimes hypertrichosis at the injection site. Aluminum allergy related to vaccination also can manifest with widespread eruptions representing systemic contact dermatitis.¹⁶

Along with vaccines, the second major source of aluminum sensitization is allergen-specific immunotherapies administered by allergists/immunologists, many of which contain aluminum hydroxide.^17,18

On the consumer product front, antiperspirants are the most common source of cutaneous exposure to aluminum. Aluminum complexes react with electrolytes in sweat to form plugs in eccrine ducts, thereby preventing sweat excretion.⁶ Allergic contact dermatitis to these products presents with axillary-vault dermatitis. There also have been reports of ACD to aluminum in sunscreen and toothpaste, with the latter implicated in causing systemic ACD.^19,20

Prevalence of Sensitization to Aluminum

There have been a few large-scale studies evaluating rates of sensitization to aluminum in general patch-test patient populations; additionally, because of the complexities of testing this metal, investigators have utilized differing formulations for patch testing. A recent Swedish study found that 0.9% of 5448 adults and 5.1% of 196 children showed positive reactions to aluminum chloride hexahydrate (ACH) 10% in petrolatum and/or aluminum lactate 12% in petrolatum.²¹ Notably, there was a significant association between aluminum allergy and history of atopy for both adults (P=.0056) and children (P=.046), which remains to be further explored. A systematic review and meta-analysis found comparable rates of aluminum allergy in 0.4% of adults and 5.6% of children without vaccine granulomas who were tested.²² With this evidence in mind, it has been recommended by contact dermatitis experts that aluminum be included in pediatric baseline patch test series and also investigated for potential inclusion in baseline series for adults.¹

Differential Diagnosis of Aluminum ACD

The differential diagnosis for subcutaneous nodules following vaccination is broad and includes various forms of panniculitis, sarcoidosis, foreign body reactions, vascular malformations, infections, and malignancies.^23-25 The diagnosis may be obscured in cases with delayed onset. Biopsy is not mandatory to establish the diagnosis; although variable histopathologic findings have been reported, a common feature is histiocytes with abundant granular cytoplasm.²⁶ It may be possible to demonstrate the presence of aluminum particles in tissue using electron microscopy and X-ray microanalysis.

For those patients who present with axillary-vault dermatitis, the differential includes ACD to more common allergens in antiperspirants (eg, fragrance), as well as other axillary dermatoses including inverse psoriasis, erythrasma, Hailey-Hailey disease, and various forms of intertrigo. Dermatitis localized to the axillary rim suggests textile allergy.

Patch Testing to Aluminum

Due to its physicochemical properties, patch testing for aluminum allergy is complicated, and historically there has been a lack of consensus on the ideal test formulation.^1,27,28 At this time, it appears that the most sensitive formulation for patch testing to aluminum is ACH 10% in petrolatum.¹ Some contact dermatitis experts recommend that children younger than 8 years should be tested with ACH 2% in petrolatum to minimize the risk of extreme patch test reactions.^29,30 In some patients sensitized to aluminum, the use of aluminum patch test chambers has been noted to produce false-positive reactions, taking the form of multiple ring-shaped reactions to the chambers themselves or reactions to certain allergens whose chemical properties cause corrosion of the aluminum within the chambers.^31-33 Therefore, when testing for suspected aluminum allergy, plastic chambers should be used; given the higher prevalence of aluminum allergy in children, some clinics routinely use plastic chambers for all pediatric patch testing.³⁴ Importantly, elemental aluminum, including empty aluminum test chambers or aluminum foil, alone is not sufficient for patch testing as it lacks sensitivity.¹ Additionally, nearly 20% of positive tests will be missed if a day 7 reading is not performed, making delayed reading a must in cases with high suspicion for aluminum allergy.²¹

Management of Aluminum Allergy

The development of pruritic subcutaneous nodules is uncomfortable for children and their guardians alike and may be associated with prolonged symptoms that negatively impact quality of life^35,36; nonetheless, expert authorities have determined that the preventive benefits of childhood vaccination far outweigh any risk posed by the presence of aluminum in vaccines.^12,13,37 Because aluminum-free formulations may not be available for all vaccines, it is essential to educate patients and families who may be at risk for developing vaccine hesitancy or avoidance.^35,36,38 Given the hypothesis that epidermal dendritic cells mediate aluminum sensitization, it has been proposed that vaccine administration via deep intramuscular rather than subcutaneous injection may mitigate the risk, but more evidence is needed to support this approach.^39,40 The good news is that the nodules tend to fade with age, with a median time to resolution of 18 to 49 months.¹⁴ In addition, patients may experience loss of sensitization to aluminum over time⁴¹; in one study, 77% of 241 children lost patch test reactivity when retested 5 to 9 years later.⁴² The exact reason for this diminishment of reactivity is not well understood. Adjunctive treatments to relieve symptoms of vaccine granulomas include topical and intralesional corticosteroids and antihistamines.

For patients reacting to aluminum in antiperspirants, there are many aluminum-free formulations on the market as well as recipes for homemade antiperspirants.⁶ On a case-by-case basis, patients may need to avoid aluminum-containing medications, permanent tattoos, and orthopedic or dental implants. To the best of our knowledge, there is no evidence suggesting a need to avoid aluminum in foods and their containers in routine daily life; although some patients report exacerbations of their symptoms associated with food-related aluminum exposures (eg, canned food, dried fruit) and improvement with dietary modification, further investigation is needed to confirm the relevance of these sources of contact.^36,38 For patients who require allergen-specific immunotherapy, aluminum-free allergen extracts are available.⁶

Final Interpretation

Exposure to aluminum is ubiquitous; although relatively uncommon, awareness of the potential for ACD to aluminum is increasingly important, particularly in children. Given the prevalence of aluminum contact allergy, it has been recommended by contact dermatitis experts for inclusion in baseline pediatric patch test series.¹ Although it is a complex issue, the development of ACD in a small proportion of children exposed to aluminum in vaccines does not outweigh the benefit of vaccination for almost all children. When conducting patch testing to aluminum, studies support testing to ACH 10% in petrolatum for adults, and consider reducing the concentration to ACH 2% for children.

Acknowledgment—The authors thank Ian Fritz, MD (South Portland, Maine), for his critical input during preparation of this article.

No time of the year is more exciting than the unveiling of the American Contact Dermatitis Society Allergen of the Year. Sometimes the selected allergen represents a completely novel cause of allergic contact dermatitis (ACD) with an unpronounceable chemical name. Not this time! The 2022 Allergen of the Year is likely to be lurking in your kitchen drawer at this very moment, as this year aluminum was chosen for this most prestigious honor.¹ But do not throw out your aluminum foil just yet—aluminum allergy tends to be confined to specific scenarios. In this article, we highlight the growing recognition of aluminum contact allergy, particularly in the pediatric population, focusing on distinct presentations of aluminum ACD, unique sources of exposure, and nuances of patch testing to this metal.

Aluminum Is All Around Us

As the third most common element in the Earth’s crust, aluminum can be found quite literally everywhere.¹ However, aluminum rarely is found in its pure elemental form; instead, it reacts with other elements around it, most commonly oxygen, to form aluminum-containing compounds. Known for their stability and safety, aluminum and its salts are incorporated in myriad products ranging from electronic equipment to foods and their packaging, medications, cosmetics, orthopedic and dental implants, and even tattoos. Aluminum also is found in the air and water supply and may even be encountered in certain workplaces, such as aircraft and machine industries. As such, contact with aluminum is all but certain in modern life.

The use of aluminum in consumer products is widely accepted as safe by public health agencies in the United States.² Although there has been public concern that aluminum could be linked to development of breast cancer or Alzheimer disease, there is no clear evidence that these conditions are associated with routine aluminum exposure through ingestion or consumer products.^3-5

Aluminum Contact Allergy

In part because of its ubiquity and in part because of the stability of aluminum-containing compounds, it was long thought that aluminum was nonallergenic. Contact allergy to elemental aluminum is rare; on the other hand, aluminum salts (the forms we are likely to encounter in daily life) are now recognized in the field of contact dermatitis as allergens of significance, particularly in the pediatric population.^1,6

First reported as a possible occupational allergen in 1944,⁷ aluminum allergy came to prominence in the 1990s in association with vaccines. Aluminum is included in some vaccines as an adjuvant that bolsters the immune response⁸; the eTable lists currently available aluminum-containing vaccines in the United States; of note, none of the COVID-19 vaccines approved in the United States or Europe contain aluminum.¹¹ Although the use of aluminum in vaccines is considered to be safe by the US Food and Drug Administration and Centers for Disease Control and Prevention,^12,13 a small number of children become sensitized to aluminum through vaccines and may develop persistent pruritic subcutaneous nodules (also known as vaccination granulomas) at the injection site; however, the incidence of this adverse effect was less than 1% in large studies including as many as 76,000 children, suggesting that it is relatively rare.^14,15 Upon patch testing, aluminum allergy has been detected in 77% to 95% of such cases.¹⁴ There is wide variation in the onset of the nodules ranging from weeks to years following vaccination.¹⁵ Due to pruritus, the examination may reveal accompanying excoriations, hyperpigmentation, and sometimes hypertrichosis at the injection site. Aluminum allergy related to vaccination also can manifest with widespread eruptions representing systemic contact dermatitis.¹⁶

Along with vaccines, the second major source of aluminum sensitization is allergen-specific immunotherapies administered by allergists/immunologists, many of which contain aluminum hydroxide.^17,18

On the consumer product front, antiperspirants are the most common source of cutaneous exposure to aluminum. Aluminum complexes react with electrolytes in sweat to form plugs in eccrine ducts, thereby preventing sweat excretion.⁶ Allergic contact dermatitis to these products presents with axillary-vault dermatitis. There also have been reports of ACD to aluminum in sunscreen and toothpaste, with the latter implicated in causing systemic ACD.^19,20

Prevalence of Sensitization to Aluminum

There have been a few large-scale studies evaluating rates of sensitization to aluminum in general patch-test patient populations; additionally, because of the complexities of testing this metal, investigators have utilized differing formulations for patch testing. A recent Swedish study found that 0.9% of 5448 adults and 5.1% of 196 children showed positive reactions to aluminum chloride hexahydrate (ACH) 10% in petrolatum and/or aluminum lactate 12% in petrolatum.²¹ Notably, there was a significant association between aluminum allergy and history of atopy for both adults (P=.0056) and children (P=.046), which remains to be further explored. A systematic review and meta-analysis found comparable rates of aluminum allergy in 0.4% of adults and 5.6% of children without vaccine granulomas who were tested.²² With this evidence in mind, it has been recommended by contact dermatitis experts that aluminum be included in pediatric baseline patch test series and also investigated for potential inclusion in baseline series for adults.¹

Differential Diagnosis of Aluminum ACD

The differential diagnosis for subcutaneous nodules following vaccination is broad and includes various forms of panniculitis, sarcoidosis, foreign body reactions, vascular malformations, infections, and malignancies.^23-25 The diagnosis may be obscured in cases with delayed onset. Biopsy is not mandatory to establish the diagnosis; although variable histopathologic findings have been reported, a common feature is histiocytes with abundant granular cytoplasm.²⁶ It may be possible to demonstrate the presence of aluminum particles in tissue using electron microscopy and X-ray microanalysis.

For those patients who present with axillary-vault dermatitis, the differential includes ACD to more common allergens in antiperspirants (eg, fragrance), as well as other axillary dermatoses including inverse psoriasis, erythrasma, Hailey-Hailey disease, and various forms of intertrigo. Dermatitis localized to the axillary rim suggests textile allergy.

Patch Testing to Aluminum

Due to its physicochemical properties, patch testing for aluminum allergy is complicated, and historically there has been a lack of consensus on the ideal test formulation.^1,27,28 At this time, it appears that the most sensitive formulation for patch testing to aluminum is ACH 10% in petrolatum.¹ Some contact dermatitis experts recommend that children younger than 8 years should be tested with ACH 2% in petrolatum to minimize the risk of extreme patch test reactions.^29,30 In some patients sensitized to aluminum, the use of aluminum patch test chambers has been noted to produce false-positive reactions, taking the form of multiple ring-shaped reactions to the chambers themselves or reactions to certain allergens whose chemical properties cause corrosion of the aluminum within the chambers.^31-33 Therefore, when testing for suspected aluminum allergy, plastic chambers should be used; given the higher prevalence of aluminum allergy in children, some clinics routinely use plastic chambers for all pediatric patch testing.³⁴ Importantly, elemental aluminum, including empty aluminum test chambers or aluminum foil, alone is not sufficient for patch testing as it lacks sensitivity.¹ Additionally, nearly 20% of positive tests will be missed if a day 7 reading is not performed, making delayed reading a must in cases with high suspicion for aluminum allergy.²¹

Management of Aluminum Allergy

The development of pruritic subcutaneous nodules is uncomfortable for children and their guardians alike and may be associated with prolonged symptoms that negatively impact quality of life^35,36; nonetheless, expert authorities have determined that the preventive benefits of childhood vaccination far outweigh any risk posed by the presence of aluminum in vaccines.^12,13,37 Because aluminum-free formulations may not be available for all vaccines, it is essential to educate patients and families who may be at risk for developing vaccine hesitancy or avoidance.^35,36,38 Given the hypothesis that epidermal dendritic cells mediate aluminum sensitization, it has been proposed that vaccine administration via deep intramuscular rather than subcutaneous injection may mitigate the risk, but more evidence is needed to support this approach.^39,40 The good news is that the nodules tend to fade with age, with a median time to resolution of 18 to 49 months.¹⁴ In addition, patients may experience loss of sensitization to aluminum over time⁴¹; in one study, 77% of 241 children lost patch test reactivity when retested 5 to 9 years later.⁴² The exact reason for this diminishment of reactivity is not well understood. Adjunctive treatments to relieve symptoms of vaccine granulomas include topical and intralesional corticosteroids and antihistamines.

For patients reacting to aluminum in antiperspirants, there are many aluminum-free formulations on the market as well as recipes for homemade antiperspirants.⁶ On a case-by-case basis, patients may need to avoid aluminum-containing medications, permanent tattoos, and orthopedic or dental implants. To the best of our knowledge, there is no evidence suggesting a need to avoid aluminum in foods and their containers in routine daily life; although some patients report exacerbations of their symptoms associated with food-related aluminum exposures (eg, canned food, dried fruit) and improvement with dietary modification, further investigation is needed to confirm the relevance of these sources of contact.^36,38 For patients who require allergen-specific immunotherapy, aluminum-free allergen extracts are available.⁶

Final Interpretation

Exposure to aluminum is ubiquitous; although relatively uncommon, awareness of the potential for ACD to aluminum is increasingly important, particularly in children. Given the prevalence of aluminum contact allergy, it has been recommended by contact dermatitis experts for inclusion in baseline pediatric patch test series.¹ Although it is a complex issue, the development of ACD in a small proportion of children exposed to aluminum in vaccines does not outweigh the benefit of vaccination for almost all children. When conducting patch testing to aluminum, studies support testing to ACH 10% in petrolatum for adults, and consider reducing the concentration to ACH 2% for children.

Acknowledgment—The authors thank Ian Fritz, MD (South Portland, Maine), for his critical input during preparation of this article.

Devices that help children control their diabetes and lead fuller lives may also give them contact dermatitis, report the authors of a new study that calls for mandatory labeling of ingredients for allergy patch testing.

“A high share of patients showed positive reactions to isobornyl acrylate adhesive (IBOA) and/or their medical devices (insulin pumps or glucose devices),” the study authors write in Contact Dermatitis. “A third of patients showed positive reactions to benzoyl peroxide (BP),” used in adhesives.

“The presence of additional unidentified allergens cannot be excluded,” they add. “Overall, our experience once more highlights the importance of having access to a full description of the chemical composition of diabetes devices and related medical devices to efficiently manage patients (including children) who experience adverse skin reactions from such devices.”

Lead study author Catarina Alves da Silva, MD, of the department of dermatology and venereology of Aarhus (Denmark) University Hospital, and her colleagues conducted a retrospective study of 15 referred patients younger than 18 years who had type 1 diabetes. The children were patch tested in the university’s dermatology clinic between 2018 and 2020 in a study of skin reactions linked with diabetes devices.
 

Contact dermatitis from device-related allergens may be common

Many children in the study reacted to chemical compounds related to their devices.

• Of the 15 patients, seven showed positive patch test reactions to IBOA, and five showed positive reactions to BP.
• Ten children had positive patch test reactions to materials from glucose sensors and insulin pumps.
• Three showed positive reactions to adhesive remover wipes.
• Five reacted to .

Marcia Hogeling, MD, a pediatric dermatologist at UCLA Health in Santa Monica, Calif., told this news organization that she expected acrylates to cause problems but was surprised that BP caused positive patch test reactions.

BP is known to be a strong irritant but a weak allergen, the authors wrote.

“It was important to identify the allergens in these devices. Hopefully, this information will be used by manufacturers to create safer products for patients,” Dr. Hogeling, who was not involved in the study, said in an email.

Dr. Hogeling acknowledged that the small sample size is a weakness of the study, although she added that the findings may help providers select devices that do not contain their patients’ contact allergens.

Ryan J. McDonough, DO, a pediatric endocrinologist and the codirector of the Diabetes Center at Children’s Mercy Kansas City (Mo.), said in an email that, despite the small sample size, the study “highlights important device-related experiences of those living with type 1 diabetes that clinicians often encounter.

“We often spend considerable time aiding patients and their families in finding ways to mitigate the reactions,” he explained. “Having a broader understanding of these chemical compositions would help clinicians choose the right devices for their patients and prevent and treat these types of reactions.”

Dr. McDonough, who was not involved in the study, noted that the patients were in Denmark, and they were able to easily transition between insulin pumps and glucose monitoring devices.

“In the U.S., it is often more challenging to switch between devices, due to insurance-related concerns.

“The true rates of reaction in the broad type 1 diabetes population are difficult to assess,” Dr. McDonough said. “The study participants were drawn from patients referred to a dermatology clinic for evaluation of reaction. Many patients either don’t develop reactions or are treated for mild symptoms locally by their endocrinologists.

“This study should serve as a call to action for continued improvements in the transparency of the components that make up the devices and adhesives, and it can provide an opportunity to develop additional interventions to prevent these reactions,” he advised.

No information regarding funding for the study was provided. The authors, Dr. Hogeling, and Dr. McDonough reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Devices that help children control their diabetes and lead fuller lives may also give them contact dermatitis, report the authors of a new study that calls for mandatory labeling of ingredients for allergy patch testing.

“A high share of patients showed positive reactions to isobornyl acrylate adhesive (IBOA) and/or their medical devices (insulin pumps or glucose devices),” the study authors write in Contact Dermatitis. “A third of patients showed positive reactions to benzoyl peroxide (BP),” used in adhesives.

“The presence of additional unidentified allergens cannot be excluded,” they add. “Overall, our experience once more highlights the importance of having access to a full description of the chemical composition of diabetes devices and related medical devices to efficiently manage patients (including children) who experience adverse skin reactions from such devices.”

Lead study author Catarina Alves da Silva, MD, of the department of dermatology and venereology of Aarhus (Denmark) University Hospital, and her colleagues conducted a retrospective study of 15 referred patients younger than 18 years who had type 1 diabetes. The children were patch tested in the university’s dermatology clinic between 2018 and 2020 in a study of skin reactions linked with diabetes devices.
 

Contact dermatitis from device-related allergens may be common

Many children in the study reacted to chemical compounds related to their devices.

• Of the 15 patients, seven showed positive patch test reactions to IBOA, and five showed positive reactions to BP.
• Ten children had positive patch test reactions to materials from glucose sensors and insulin pumps.
• Three showed positive reactions to adhesive remover wipes.
• Five reacted to .

Marcia Hogeling, MD, a pediatric dermatologist at UCLA Health in Santa Monica, Calif., told this news organization that she expected acrylates to cause problems but was surprised that BP caused positive patch test reactions.

BP is known to be a strong irritant but a weak allergen, the authors wrote.

“It was important to identify the allergens in these devices. Hopefully, this information will be used by manufacturers to create safer products for patients,” Dr. Hogeling, who was not involved in the study, said in an email.

Dr. Hogeling acknowledged that the small sample size is a weakness of the study, although she added that the findings may help providers select devices that do not contain their patients’ contact allergens.

Ryan J. McDonough, DO, a pediatric endocrinologist and the codirector of the Diabetes Center at Children’s Mercy Kansas City (Mo.), said in an email that, despite the small sample size, the study “highlights important device-related experiences of those living with type 1 diabetes that clinicians often encounter.

“We often spend considerable time aiding patients and their families in finding ways to mitigate the reactions,” he explained. “Having a broader understanding of these chemical compositions would help clinicians choose the right devices for their patients and prevent and treat these types of reactions.”

Dr. McDonough, who was not involved in the study, noted that the patients were in Denmark, and they were able to easily transition between insulin pumps and glucose monitoring devices.

“In the U.S., it is often more challenging to switch between devices, due to insurance-related concerns.

“The true rates of reaction in the broad type 1 diabetes population are difficult to assess,” Dr. McDonough said. “The study participants were drawn from patients referred to a dermatology clinic for evaluation of reaction. Many patients either don’t develop reactions or are treated for mild symptoms locally by their endocrinologists.

“This study should serve as a call to action for continued improvements in the transparency of the components that make up the devices and adhesives, and it can provide an opportunity to develop additional interventions to prevent these reactions,” he advised.

No information regarding funding for the study was provided. The authors, Dr. Hogeling, and Dr. McDonough reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Devices that help children control their diabetes and lead fuller lives may also give them contact dermatitis, report the authors of a new study that calls for mandatory labeling of ingredients for allergy patch testing.

“A high share of patients showed positive reactions to isobornyl acrylate adhesive (IBOA) and/or their medical devices (insulin pumps or glucose devices),” the study authors write in Contact Dermatitis. “A third of patients showed positive reactions to benzoyl peroxide (BP),” used in adhesives.

“The presence of additional unidentified allergens cannot be excluded,” they add. “Overall, our experience once more highlights the importance of having access to a full description of the chemical composition of diabetes devices and related medical devices to efficiently manage patients (including children) who experience adverse skin reactions from such devices.”

Lead study author Catarina Alves da Silva, MD, of the department of dermatology and venereology of Aarhus (Denmark) University Hospital, and her colleagues conducted a retrospective study of 15 referred patients younger than 18 years who had type 1 diabetes. The children were patch tested in the university’s dermatology clinic between 2018 and 2020 in a study of skin reactions linked with diabetes devices.
 

Contact dermatitis from device-related allergens may be common

Many children in the study reacted to chemical compounds related to their devices.

• Of the 15 patients, seven showed positive patch test reactions to IBOA, and five showed positive reactions to BP.
• Ten children had positive patch test reactions to materials from glucose sensors and insulin pumps.
• Three showed positive reactions to adhesive remover wipes.
• Five reacted to .

Marcia Hogeling, MD, a pediatric dermatologist at UCLA Health in Santa Monica, Calif., told this news organization that she expected acrylates to cause problems but was surprised that BP caused positive patch test reactions.

BP is known to be a strong irritant but a weak allergen, the authors wrote.

“It was important to identify the allergens in these devices. Hopefully, this information will be used by manufacturers to create safer products for patients,” Dr. Hogeling, who was not involved in the study, said in an email.

Dr. Hogeling acknowledged that the small sample size is a weakness of the study, although she added that the findings may help providers select devices that do not contain their patients’ contact allergens.

Ryan J. McDonough, DO, a pediatric endocrinologist and the codirector of the Diabetes Center at Children’s Mercy Kansas City (Mo.), said in an email that, despite the small sample size, the study “highlights important device-related experiences of those living with type 1 diabetes that clinicians often encounter.

“We often spend considerable time aiding patients and their families in finding ways to mitigate the reactions,” he explained. “Having a broader understanding of these chemical compositions would help clinicians choose the right devices for their patients and prevent and treat these types of reactions.”

Dr. McDonough, who was not involved in the study, noted that the patients were in Denmark, and they were able to easily transition between insulin pumps and glucose monitoring devices.

“In the U.S., it is often more challenging to switch between devices, due to insurance-related concerns.

“The true rates of reaction in the broad type 1 diabetes population are difficult to assess,” Dr. McDonough said. “The study participants were drawn from patients referred to a dermatology clinic for evaluation of reaction. Many patients either don’t develop reactions or are treated for mild symptoms locally by their endocrinologists.

“This study should serve as a call to action for continued improvements in the transparency of the components that make up the devices and adhesives, and it can provide an opportunity to develop additional interventions to prevent these reactions,” he advised.

No information regarding funding for the study was provided. The authors, Dr. Hogeling, and Dr. McDonough reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Lupus erythematosus tumidus (LET) is a rare photosensitive dermatosis¹ that previously was considered a subtype of chronic cutaneous lupus erythematosus; however, the clinical course and favorable prognosis of LET led to its reclassification into another category, called intermittent cutaneous lupus erythematosus.² Although known about for more than 100 years, the association of LET with systemic lupus erythematosus (SLE), its autoantibody profile, and its prognosis are not well characterized. The purpose of this study was to describe the demographics, clinical characteristics, autoantibody profile, comorbidities, and treatment of LET based on a retrospective review of patients with LET.

Methods

A retrospective review was conducted in patients with histologically diagnosed LET who presented to the Department of Dermatology at the Wake Forest School of Medicine (Winston-Salem, North Carolina) over 6 years (July 2012 to July 2018). Inclusion criteria included males or females aged 18 to 75 years with clinical and histopathology-proven LET, which was defined as a superficial and deep lymphocytic infiltrate with abundant mucin deposition in the reticular dermis and absent or focal dermoepidermal junction alterations. Exclusion criteria included males or females younger than 18 years or older than 75 years or patients without clinical and histopathologically proven LET. Medical records were evaluated for demographics, clinical characteristics, diagnoses, autoantibodies, treatment, and recurrence. Photosensitivity was confirmed by clinical history. This study was approved by the Wake Forest School of Medicine institutional review board.

Results

Twenty-five patients were included in the study (eTable). The mean age (SD) at diagnosis was 46 (10.9) years, with a male to female ratio of 1:4. Twenty-two (88%) patients were White non-Hispanic, whereas 3 (12%) were Black. Lupus erythematosus tumidus most commonly affected the trunk (18/25 [72%]) and upper extremities (18/25 [72%]), followed by the head and neck (15/25 [60%]) and lower extremities (8/25 [32%])(Figure 1). The most common morphologies were plaques (18/25 [72%]), papules (17/25 [68%]), and nodules (6/25 [24%])(Figures 2 and 3). Most patients experienced painful (14/25 [56%]) or pruritic (13/25 [52%]) lesions as well as photosensitivity (13/25 [52%]). Of all measured autoantibodies, 5 of 22 (23%) patients had positive antinuclear antibody (ANA) titers greater than 1:80, 1 of 14 (7%) patients had positive anti-Ro (anti-SSA), 1 of 14 (7%) had positive anti-La (anti-SSB), 2 of 10 (20%) had positive anti–double-stranded DNA, and 0 of 6 (0%) patients had positive anti-Smith antibodies. Four (16%) patients with SLE had skin and joint involvement, whereas 1 had lupus nephritis. One (4%) patient had discoid lupus erythematosus (DLE). Seventeen (68%) patients reported recurrences or flares. The mean duration of symptoms (SD) was 28 (44) months.

Topical corticosteroids (21/25 [84%]) and hydroxychloroquine (20/25 [80%]) were the most commonly prescribed treatments. Hydroxychloroquine monotherapy achieved clearance or almost clearance in 12 (60%) patients. Four patients were prescribed thalidomide after hydroxychloroquine monotherapy failed; 2 achieved complete clearance with thalidomide and hydroxychloroquine, 1 achieved complete clearance with thalidomide monotherapy, and 1 improved but did not clear. Four patients were concurrently started on quinacrine (mepacrine) after hydroxychloroquine monotherapy failed; 1 patient had no clearance, 1 discontinued because of allergy, 1 improved, and 1 cleared. Four patients had short courses of prednisone lasting 1 to 4 weeks. Three of 4 patients treated with methotrexate discontinued because of adverse effects, and 1 patient improved. Other prescribed treatments included topical calcineurin inhibitors (10/25 [40%]), dapsone (1/25 [4%]), and clofazimine (1/25 [4%]).

Comment

Prevalence of LET—Although other European LET case series reported a male predominance or equal male to female ratio, our case series reported female predominance (1:4).^1,3-5 Our male to female ratio resembles similar ratios in DLE and subacute lupus erythematosus, whereas relative to our study, SLE male to female ratios favored females over males.^6,7

Clinical Distribution of LET—In one study enrolling 24 patients with LET, 79% (19/24) of patients had facial involvement, 50% (12/24) had V-neck involvement, 50% (12/24) had back involvement, and 46% (11/24) had arm involvement,² whereas our study reported 72% involvement of the trunk, 72% involvement of the upper extremities, 60% involvement of the head and neck region, and 32% involvement of the lower extremities. Although our study reported more lower extremity involvement, the aforementioned study used precise topographic locations, whereas we used more generalized topographic locations. Therefore, it was difficult to compare disease distribution between both studies.²

Presence of Autoantibodies and Comorbidities—Of the 22 patients tested for ANA, 23% reported titers greater than 1:80, similar to the 20% positive ANA prevalence in an LET case series of 25 patients.⁵ Of 4 patients diagnosed with SLE, 3 had articular and skin involvement, and 1 had renal involvement. These findings resemble a similar LET case series.² Nonetheless, given the numerous skin criteria in the American College of Rheumatology SLE classification criteria, patients with predominant skin disease and positive autoantibodies are diagnosed as having SLE without notable extracutaneous involvement.² Therefore, SLE diagnosis in the setting of LET could be reassessed periodically in this population. One patient in our study was diagnosed with DLE several years later. It is uncommon for LET to be reported concomitantly with DLE.⁸

Treatment of LET—Evidence supporting efficacious treatment options for LET is limited to case series. Sun protection is recommended in all patients with LET. Earlier case series reported a high response rate with sun protection and topical corticosteroids, with 19% to 55% of patients requiring subsequent systemic antimalarials.^3,4 However, one case series presented a need for systemic antimalarials,⁵ similar to our study. Hydroxychloroquine 200 to 400 mg daily is considered the first-line systemic treatment for LET. Its response rate varies among studies and may be influenced by dosage.^1,3 Second-line treatments include methotrexate 7.5 to 25 mg once weekly, thalidomide 50 to 100 mg daily, and quinacrine. However, quinacrine is not currently commercially available. Thalidomide and quinacrine represented useful alternatives when hydroxychloroquine monotherapy failed. As with other immunomodulators, adverse effects should be monitored periodically.

Conclusion

Lupus erythematosus tumidus is characterized by erythematous papules and plaques that may be tender or pruritic. It follows an intermittent course and rarely is associated with SLE. Hydroxychloroquine is considered the first-line systemic treatment; however, recalcitrant disease could be managed with other immunomodulators, including methotrexate, thalidomide, or quinacrine.

Lupus erythematosus tumidus (LET) is a rare photosensitive dermatosis¹ that previously was considered a subtype of chronic cutaneous lupus erythematosus; however, the clinical course and favorable prognosis of LET led to its reclassification into another category, called intermittent cutaneous lupus erythematosus.² Although known about for more than 100 years, the association of LET with systemic lupus erythematosus (SLE), its autoantibody profile, and its prognosis are not well characterized. The purpose of this study was to describe the demographics, clinical characteristics, autoantibody profile, comorbidities, and treatment of LET based on a retrospective review of patients with LET.

Methods

A retrospective review was conducted in patients with histologically diagnosed LET who presented to the Department of Dermatology at the Wake Forest School of Medicine (Winston-Salem, North Carolina) over 6 years (July 2012 to July 2018). Inclusion criteria included males or females aged 18 to 75 years with clinical and histopathology-proven LET, which was defined as a superficial and deep lymphocytic infiltrate with abundant mucin deposition in the reticular dermis and absent or focal dermoepidermal junction alterations. Exclusion criteria included males or females younger than 18 years or older than 75 years or patients without clinical and histopathologically proven LET. Medical records were evaluated for demographics, clinical characteristics, diagnoses, autoantibodies, treatment, and recurrence. Photosensitivity was confirmed by clinical history. This study was approved by the Wake Forest School of Medicine institutional review board.

Results

Twenty-five patients were included in the study (eTable). The mean age (SD) at diagnosis was 46 (10.9) years, with a male to female ratio of 1:4. Twenty-two (88%) patients were White non-Hispanic, whereas 3 (12%) were Black. Lupus erythematosus tumidus most commonly affected the trunk (18/25 [72%]) and upper extremities (18/25 [72%]), followed by the head and neck (15/25 [60%]) and lower extremities (8/25 [32%])(Figure 1). The most common morphologies were plaques (18/25 [72%]), papules (17/25 [68%]), and nodules (6/25 [24%])(Figures 2 and 3). Most patients experienced painful (14/25 [56%]) or pruritic (13/25 [52%]) lesions as well as photosensitivity (13/25 [52%]). Of all measured autoantibodies, 5 of 22 (23%) patients had positive antinuclear antibody (ANA) titers greater than 1:80, 1 of 14 (7%) patients had positive anti-Ro (anti-SSA), 1 of 14 (7%) had positive anti-La (anti-SSB), 2 of 10 (20%) had positive anti–double-stranded DNA, and 0 of 6 (0%) patients had positive anti-Smith antibodies. Four (16%) patients with SLE had skin and joint involvement, whereas 1 had lupus nephritis. One (4%) patient had discoid lupus erythematosus (DLE). Seventeen (68%) patients reported recurrences or flares. The mean duration of symptoms (SD) was 28 (44) months.

Topical corticosteroids (21/25 [84%]) and hydroxychloroquine (20/25 [80%]) were the most commonly prescribed treatments. Hydroxychloroquine monotherapy achieved clearance or almost clearance in 12 (60%) patients. Four patients were prescribed thalidomide after hydroxychloroquine monotherapy failed; 2 achieved complete clearance with thalidomide and hydroxychloroquine, 1 achieved complete clearance with thalidomide monotherapy, and 1 improved but did not clear. Four patients were concurrently started on quinacrine (mepacrine) after hydroxychloroquine monotherapy failed; 1 patient had no clearance, 1 discontinued because of allergy, 1 improved, and 1 cleared. Four patients had short courses of prednisone lasting 1 to 4 weeks. Three of 4 patients treated with methotrexate discontinued because of adverse effects, and 1 patient improved. Other prescribed treatments included topical calcineurin inhibitors (10/25 [40%]), dapsone (1/25 [4%]), and clofazimine (1/25 [4%]).

Comment

Prevalence of LET—Although other European LET case series reported a male predominance or equal male to female ratio, our case series reported female predominance (1:4).^1,3-5 Our male to female ratio resembles similar ratios in DLE and subacute lupus erythematosus, whereas relative to our study, SLE male to female ratios favored females over males.^6,7

Clinical Distribution of LET—In one study enrolling 24 patients with LET, 79% (19/24) of patients had facial involvement, 50% (12/24) had V-neck involvement, 50% (12/24) had back involvement, and 46% (11/24) had arm involvement,² whereas our study reported 72% involvement of the trunk, 72% involvement of the upper extremities, 60% involvement of the head and neck region, and 32% involvement of the lower extremities. Although our study reported more lower extremity involvement, the aforementioned study used precise topographic locations, whereas we used more generalized topographic locations. Therefore, it was difficult to compare disease distribution between both studies.²

Presence of Autoantibodies and Comorbidities—Of the 22 patients tested for ANA, 23% reported titers greater than 1:80, similar to the 20% positive ANA prevalence in an LET case series of 25 patients.⁵ Of 4 patients diagnosed with SLE, 3 had articular and skin involvement, and 1 had renal involvement. These findings resemble a similar LET case series.² Nonetheless, given the numerous skin criteria in the American College of Rheumatology SLE classification criteria, patients with predominant skin disease and positive autoantibodies are diagnosed as having SLE without notable extracutaneous involvement.² Therefore, SLE diagnosis in the setting of LET could be reassessed periodically in this population. One patient in our study was diagnosed with DLE several years later. It is uncommon for LET to be reported concomitantly with DLE.⁸

Treatment of LET—Evidence supporting efficacious treatment options for LET is limited to case series. Sun protection is recommended in all patients with LET. Earlier case series reported a high response rate with sun protection and topical corticosteroids, with 19% to 55% of patients requiring subsequent systemic antimalarials.^3,4 However, one case series presented a need for systemic antimalarials,⁵ similar to our study. Hydroxychloroquine 200 to 400 mg daily is considered the first-line systemic treatment for LET. Its response rate varies among studies and may be influenced by dosage.^1,3 Second-line treatments include methotrexate 7.5 to 25 mg once weekly, thalidomide 50 to 100 mg daily, and quinacrine. However, quinacrine is not currently commercially available. Thalidomide and quinacrine represented useful alternatives when hydroxychloroquine monotherapy failed. As with other immunomodulators, adverse effects should be monitored periodically.

Conclusion

Lupus erythematosus tumidus is characterized by erythematous papules and plaques that may be tender or pruritic. It follows an intermittent course and rarely is associated with SLE. Hydroxychloroquine is considered the first-line systemic treatment; however, recalcitrant disease could be managed with other immunomodulators, including methotrexate, thalidomide, or quinacrine.

Lupus erythematosus tumidus (LET) is a rare photosensitive dermatosis¹ that previously was considered a subtype of chronic cutaneous lupus erythematosus; however, the clinical course and favorable prognosis of LET led to its reclassification into another category, called intermittent cutaneous lupus erythematosus.² Although known about for more than 100 years, the association of LET with systemic lupus erythematosus (SLE), its autoantibody profile, and its prognosis are not well characterized. The purpose of this study was to describe the demographics, clinical characteristics, autoantibody profile, comorbidities, and treatment of LET based on a retrospective review of patients with LET.

Methods

A retrospective review was conducted in patients with histologically diagnosed LET who presented to the Department of Dermatology at the Wake Forest School of Medicine (Winston-Salem, North Carolina) over 6 years (July 2012 to July 2018). Inclusion criteria included males or females aged 18 to 75 years with clinical and histopathology-proven LET, which was defined as a superficial and deep lymphocytic infiltrate with abundant mucin deposition in the reticular dermis and absent or focal dermoepidermal junction alterations. Exclusion criteria included males or females younger than 18 years or older than 75 years or patients without clinical and histopathologically proven LET. Medical records were evaluated for demographics, clinical characteristics, diagnoses, autoantibodies, treatment, and recurrence. Photosensitivity was confirmed by clinical history. This study was approved by the Wake Forest School of Medicine institutional review board.

Results

Twenty-five patients were included in the study (eTable). The mean age (SD) at diagnosis was 46 (10.9) years, with a male to female ratio of 1:4. Twenty-two (88%) patients were White non-Hispanic, whereas 3 (12%) were Black. Lupus erythematosus tumidus most commonly affected the trunk (18/25 [72%]) and upper extremities (18/25 [72%]), followed by the head and neck (15/25 [60%]) and lower extremities (8/25 [32%])(Figure 1). The most common morphologies were plaques (18/25 [72%]), papules (17/25 [68%]), and nodules (6/25 [24%])(Figures 2 and 3). Most patients experienced painful (14/25 [56%]) or pruritic (13/25 [52%]) lesions as well as photosensitivity (13/25 [52%]). Of all measured autoantibodies, 5 of 22 (23%) patients had positive antinuclear antibody (ANA) titers greater than 1:80, 1 of 14 (7%) patients had positive anti-Ro (anti-SSA), 1 of 14 (7%) had positive anti-La (anti-SSB), 2 of 10 (20%) had positive anti–double-stranded DNA, and 0 of 6 (0%) patients had positive anti-Smith antibodies. Four (16%) patients with SLE had skin and joint involvement, whereas 1 had lupus nephritis. One (4%) patient had discoid lupus erythematosus (DLE). Seventeen (68%) patients reported recurrences or flares. The mean duration of symptoms (SD) was 28 (44) months.

Topical corticosteroids (21/25 [84%]) and hydroxychloroquine (20/25 [80%]) were the most commonly prescribed treatments. Hydroxychloroquine monotherapy achieved clearance or almost clearance in 12 (60%) patients. Four patients were prescribed thalidomide after hydroxychloroquine monotherapy failed; 2 achieved complete clearance with thalidomide and hydroxychloroquine, 1 achieved complete clearance with thalidomide monotherapy, and 1 improved but did not clear. Four patients were concurrently started on quinacrine (mepacrine) after hydroxychloroquine monotherapy failed; 1 patient had no clearance, 1 discontinued because of allergy, 1 improved, and 1 cleared. Four patients had short courses of prednisone lasting 1 to 4 weeks. Three of 4 patients treated with methotrexate discontinued because of adverse effects, and 1 patient improved. Other prescribed treatments included topical calcineurin inhibitors (10/25 [40%]), dapsone (1/25 [4%]), and clofazimine (1/25 [4%]).

Comment

Prevalence of LET—Although other European LET case series reported a male predominance or equal male to female ratio, our case series reported female predominance (1:4).^1,3-5 Our male to female ratio resembles similar ratios in DLE and subacute lupus erythematosus, whereas relative to our study, SLE male to female ratios favored females over males.^6,7

Clinical Distribution of LET—In one study enrolling 24 patients with LET, 79% (19/24) of patients had facial involvement, 50% (12/24) had V-neck involvement, 50% (12/24) had back involvement, and 46% (11/24) had arm involvement,² whereas our study reported 72% involvement of the trunk, 72% involvement of the upper extremities, 60% involvement of the head and neck region, and 32% involvement of the lower extremities. Although our study reported more lower extremity involvement, the aforementioned study used precise topographic locations, whereas we used more generalized topographic locations. Therefore, it was difficult to compare disease distribution between both studies.²

Presence of Autoantibodies and Comorbidities—Of the 22 patients tested for ANA, 23% reported titers greater than 1:80, similar to the 20% positive ANA prevalence in an LET case series of 25 patients.⁵ Of 4 patients diagnosed with SLE, 3 had articular and skin involvement, and 1 had renal involvement. These findings resemble a similar LET case series.² Nonetheless, given the numerous skin criteria in the American College of Rheumatology SLE classification criteria, patients with predominant skin disease and positive autoantibodies are diagnosed as having SLE without notable extracutaneous involvement.² Therefore, SLE diagnosis in the setting of LET could be reassessed periodically in this population. One patient in our study was diagnosed with DLE several years later. It is uncommon for LET to be reported concomitantly with DLE.⁸

Treatment of LET—Evidence supporting efficacious treatment options for LET is limited to case series. Sun protection is recommended in all patients with LET. Earlier case series reported a high response rate with sun protection and topical corticosteroids, with 19% to 55% of patients requiring subsequent systemic antimalarials.^3,4 However, one case series presented a need for systemic antimalarials,⁵ similar to our study. Hydroxychloroquine 200 to 400 mg daily is considered the first-line systemic treatment for LET. Its response rate varies among studies and may be influenced by dosage.^1,3 Second-line treatments include methotrexate 7.5 to 25 mg once weekly, thalidomide 50 to 100 mg daily, and quinacrine. However, quinacrine is not currently commercially available. Thalidomide and quinacrine represented useful alternatives when hydroxychloroquine monotherapy failed. As with other immunomodulators, adverse effects should be monitored periodically.

Conclusion

Lupus erythematosus tumidus is characterized by erythematous papules and plaques that may be tender or pruritic. It follows an intermittent course and rarely is associated with SLE. Hydroxychloroquine is considered the first-line systemic treatment; however, recalcitrant disease could be managed with other immunomodulators, including methotrexate, thalidomide, or quinacrine.

Airbags are lifesaving during motor vehicle accidents (MVAs), but their deployment has been associated with skin issues such as irritant dermatitis¹; lacerations²; abrasions³; and thermal, friction, and chemical burns.^4-6 Ocular issues such as alkaline chemical keratitis⁷ and ocular alkali injuries⁸ also have been described.

Airbag deployment is triggered by rapid deceleration and impact, which ignite a sodium azide cartridge, causing the woven nylon bag to inflate with hydrocarbon gases.⁸ This leads to release of sodium hydroxide, sodium bicarbonate, and metallic oxides in an aerosolized form. If a tear in the meshwork of the airbag occurs, exposure to an even larger amount of powder containing caustic alkali chemicals can occur.⁸

We describe a patient who developed a bullous reaction to airbag contents after he was involved in an MVA in which the airbag deployed.

Case Report

A 35-year-old man with a history of type 2 diabetes mellitus and chronic hepatitis B presented to the dermatology clinic for an evaluation of new-onset blisters. The rash occurred 1 day after the patient was involved in an MVA in which he was exposed to the airbag’s contents after it burst. He had been evaluated twice in the emergency department for the skin eruption before being referred to dermatology. He noted the lesions were pruritic and painful. Prior treatments included silver sulfadiazine cream 1% and clobetasol cream 0.05%, though he discontinued using the latter because of burning with application. Physical examination revealed tense vesicles and bullae on an erythematous base on the right lower flank, forearms, and legs, with the exception of the lower right leg where a cast had been from a prior injury (Figure 1).

Two punch biopsies of the left arm were performed and sent for hematoxylin and eosin staining and direct immunofluorescence to rule out bullous diseases, such as bullous pemphigoid, linear IgA, and bullous lupus. Hematoxylin and eosin staining revealed extensive spongiosis with blister formation and a dense perivascular infiltrate in the superficial and mid dermis composed of lymphocytes with numerous scattered eosinophils (Figures 2 and 3). Direct immunofluorescence studies were negative. Treatment with oral prednisone and oral antihistamines was initiated.

At 10-day follow-up, the patient had a few residual bullae; most lesions were demonstrating various stages of healing (Figure 4). The patient’s cast had been removed, and there were no lesions in this previously covered area. At 6-week follow-up he had continued healing of the bullae and erosions as well as postinflammatory hyperpigmentation (Figure 5).

Comment

With the advent of airbags for safety purposes, these potentially lifesaving devices also have been known to cause injury.⁹ In 1998, the most commonly reported airbag injuries were ocular injuries.¹⁰ Cutaneous manifestations of airbag injury are less well known.¹¹

Two cases of airbag deployment with skin blistering have been reported in the literature based on a PubMed search of articles indexed for MEDLINE using the terms airbag blistering or airbag bullae^12,13; however, the blistering was described in the context of a burn. One case of the effects of airbag deployment residue highlights a patient arriving to the emergency department with erythema and blisters on the hands within 48 hours of airbag deployment in an MVA, and the treatment was standard burn therapy.¹² Another case report described a patient with a second-degree burn with a 12-cm blister occurring on the radial side of the hand and distal forearm following an MVA and airbag deployment, which was treated conservatively.¹³ Cases of thermal burns, chemical burns, and irritant contact dermatitis after airbag deployment have been described in the literature.^{4-6,11,12,14,15} Our patient’s distal right lower leg was covered with a cast for osteomyelitis, and no blisters had developed in this area. It is likely that the transfer of airbag contents occurred during the process of unbuckling his seatbelt, which could explain the bullae that developed on the right flank. Per the Centers for Disease Control and Prevention, individuals should quickly remove clothing and wash their body with large amounts of soap and water following exposure to sodium azide.¹⁶

In 1989, the Federal Motor Vehicle Safety Standard No. 208 (occupant crash protection) became effective, stating all cars must have vehicle crash protection.¹² Prior to 1993, it was reported that there had been no associated chemical injuries with airbag deployment. Subsequently, a 6-month retrospective study in 1993 showed that dermal injuries were found in connection with the presence of sodium hydroxide in automobile airbags.¹² By 2004, it was known that airbags could cause chemical and thermal burns in addition to traumatic injuries from deployment.¹ Since 2007, all motor vehicles have been required to have advanced airbags, which are engineered to sense the presence of passengers and determine if the airbag will deploy, and if so, how much to deploy to minimize airbag-related injury.³

The brand of car that our patient drove during the MVA is one with known airbag recalls due to safety defects; however, the year and actual model of the vehicle are not known, so specific information about the airbag in question is not available. It has been noted that some defective airbag inflators that were exposed to excess moisture during the manufacturing process could explode during deployment, causing shrapnel and airbag rupture, which has been linked to nearly 300 injuries worldwide.¹⁷

Conclusion

It is evident that the use of airbag devices reduces morbidity and mortality due to MVAs.⁹ It also had been reported that up to 96% of airbag-related injuries are relatively minor, which many would argue justifies their use.¹⁸ Furthermore, it has been reported that 99.8% of skin injuries following airbag deployment are minor.¹⁹ In the United States, it is mandated that every vehicle have functional airbags installed.⁸

This case highlights the potential for substantial airbag-induced skin reactions, specifically a bullous reaction, following airbag deployment. The persistent pruritus and lasting postinflammatory hyperpigmentation seen in this case were certainly worrisome for our patient. We also present this case to remind dermatology providers of possible treatment approaches to these skin reactions. Immediate cleansing of the affected areas of skin may help avoid such reactions.

Airbags are lifesaving during motor vehicle accidents (MVAs), but their deployment has been associated with skin issues such as irritant dermatitis¹; lacerations²; abrasions³; and thermal, friction, and chemical burns.^4-6 Ocular issues such as alkaline chemical keratitis⁷ and ocular alkali injuries⁸ also have been described.

Airbag deployment is triggered by rapid deceleration and impact, which ignite a sodium azide cartridge, causing the woven nylon bag to inflate with hydrocarbon gases.⁸ This leads to release of sodium hydroxide, sodium bicarbonate, and metallic oxides in an aerosolized form. If a tear in the meshwork of the airbag occurs, exposure to an even larger amount of powder containing caustic alkali chemicals can occur.⁸

We describe a patient who developed a bullous reaction to airbag contents after he was involved in an MVA in which the airbag deployed.

Case Report

A 35-year-old man with a history of type 2 diabetes mellitus and chronic hepatitis B presented to the dermatology clinic for an evaluation of new-onset blisters. The rash occurred 1 day after the patient was involved in an MVA in which he was exposed to the airbag’s contents after it burst. He had been evaluated twice in the emergency department for the skin eruption before being referred to dermatology. He noted the lesions were pruritic and painful. Prior treatments included silver sulfadiazine cream 1% and clobetasol cream 0.05%, though he discontinued using the latter because of burning with application. Physical examination revealed tense vesicles and bullae on an erythematous base on the right lower flank, forearms, and legs, with the exception of the lower right leg where a cast had been from a prior injury (Figure 1).

Two punch biopsies of the left arm were performed and sent for hematoxylin and eosin staining and direct immunofluorescence to rule out bullous diseases, such as bullous pemphigoid, linear IgA, and bullous lupus. Hematoxylin and eosin staining revealed extensive spongiosis with blister formation and a dense perivascular infiltrate in the superficial and mid dermis composed of lymphocytes with numerous scattered eosinophils (Figures 2 and 3). Direct immunofluorescence studies were negative. Treatment with oral prednisone and oral antihistamines was initiated.

At 10-day follow-up, the patient had a few residual bullae; most lesions were demonstrating various stages of healing (Figure 4). The patient’s cast had been removed, and there were no lesions in this previously covered area. At 6-week follow-up he had continued healing of the bullae and erosions as well as postinflammatory hyperpigmentation (Figure 5).

Comment

With the advent of airbags for safety purposes, these potentially lifesaving devices also have been known to cause injury.⁹ In 1998, the most commonly reported airbag injuries were ocular injuries.¹⁰ Cutaneous manifestations of airbag injury are less well known.¹¹

Two cases of airbag deployment with skin blistering have been reported in the literature based on a PubMed search of articles indexed for MEDLINE using the terms airbag blistering or airbag bullae^12,13; however, the blistering was described in the context of a burn. One case of the effects of airbag deployment residue highlights a patient arriving to the emergency department with erythema and blisters on the hands within 48 hours of airbag deployment in an MVA, and the treatment was standard burn therapy.¹² Another case report described a patient with a second-degree burn with a 12-cm blister occurring on the radial side of the hand and distal forearm following an MVA and airbag deployment, which was treated conservatively.¹³ Cases of thermal burns, chemical burns, and irritant contact dermatitis after airbag deployment have been described in the literature.^{4-6,11,12,14,15} Our patient’s distal right lower leg was covered with a cast for osteomyelitis, and no blisters had developed in this area. It is likely that the transfer of airbag contents occurred during the process of unbuckling his seatbelt, which could explain the bullae that developed on the right flank. Per the Centers for Disease Control and Prevention, individuals should quickly remove clothing and wash their body with large amounts of soap and water following exposure to sodium azide.¹⁶

In 1989, the Federal Motor Vehicle Safety Standard No. 208 (occupant crash protection) became effective, stating all cars must have vehicle crash protection.¹² Prior to 1993, it was reported that there had been no associated chemical injuries with airbag deployment. Subsequently, a 6-month retrospective study in 1993 showed that dermal injuries were found in connection with the presence of sodium hydroxide in automobile airbags.¹² By 2004, it was known that airbags could cause chemical and thermal burns in addition to traumatic injuries from deployment.¹ Since 2007, all motor vehicles have been required to have advanced airbags, which are engineered to sense the presence of passengers and determine if the airbag will deploy, and if so, how much to deploy to minimize airbag-related injury.³

The brand of car that our patient drove during the MVA is one with known airbag recalls due to safety defects; however, the year and actual model of the vehicle are not known, so specific information about the airbag in question is not available. It has been noted that some defective airbag inflators that were exposed to excess moisture during the manufacturing process could explode during deployment, causing shrapnel and airbag rupture, which has been linked to nearly 300 injuries worldwide.¹⁷

Conclusion

It is evident that the use of airbag devices reduces morbidity and mortality due to MVAs.⁹ It also had been reported that up to 96% of airbag-related injuries are relatively minor, which many would argue justifies their use.¹⁸ Furthermore, it has been reported that 99.8% of skin injuries following airbag deployment are minor.¹⁹ In the United States, it is mandated that every vehicle have functional airbags installed.⁸

This case highlights the potential for substantial airbag-induced skin reactions, specifically a bullous reaction, following airbag deployment. The persistent pruritus and lasting postinflammatory hyperpigmentation seen in this case were certainly worrisome for our patient. We also present this case to remind dermatology providers of possible treatment approaches to these skin reactions. Immediate cleansing of the affected areas of skin may help avoid such reactions.

Airbags are lifesaving during motor vehicle accidents (MVAs), but their deployment has been associated with skin issues such as irritant dermatitis¹; lacerations²; abrasions³; and thermal, friction, and chemical burns.^4-6 Ocular issues such as alkaline chemical keratitis⁷ and ocular alkali injuries⁸ also have been described.

Airbag deployment is triggered by rapid deceleration and impact, which ignite a sodium azide cartridge, causing the woven nylon bag to inflate with hydrocarbon gases.⁸ This leads to release of sodium hydroxide, sodium bicarbonate, and metallic oxides in an aerosolized form. If a tear in the meshwork of the airbag occurs, exposure to an even larger amount of powder containing caustic alkali chemicals can occur.⁸

We describe a patient who developed a bullous reaction to airbag contents after he was involved in an MVA in which the airbag deployed.

Case Report

A 35-year-old man with a history of type 2 diabetes mellitus and chronic hepatitis B presented to the dermatology clinic for an evaluation of new-onset blisters. The rash occurred 1 day after the patient was involved in an MVA in which he was exposed to the airbag’s contents after it burst. He had been evaluated twice in the emergency department for the skin eruption before being referred to dermatology. He noted the lesions were pruritic and painful. Prior treatments included silver sulfadiazine cream 1% and clobetasol cream 0.05%, though he discontinued using the latter because of burning with application. Physical examination revealed tense vesicles and bullae on an erythematous base on the right lower flank, forearms, and legs, with the exception of the lower right leg where a cast had been from a prior injury (Figure 1).

Two punch biopsies of the left arm were performed and sent for hematoxylin and eosin staining and direct immunofluorescence to rule out bullous diseases, such as bullous pemphigoid, linear IgA, and bullous lupus. Hematoxylin and eosin staining revealed extensive spongiosis with blister formation and a dense perivascular infiltrate in the superficial and mid dermis composed of lymphocytes with numerous scattered eosinophils (Figures 2 and 3). Direct immunofluorescence studies were negative. Treatment with oral prednisone and oral antihistamines was initiated.

At 10-day follow-up, the patient had a few residual bullae; most lesions were demonstrating various stages of healing (Figure 4). The patient’s cast had been removed, and there were no lesions in this previously covered area. At 6-week follow-up he had continued healing of the bullae and erosions as well as postinflammatory hyperpigmentation (Figure 5).

Comment

With the advent of airbags for safety purposes, these potentially lifesaving devices also have been known to cause injury.⁹ In 1998, the most commonly reported airbag injuries were ocular injuries.¹⁰ Cutaneous manifestations of airbag injury are less well known.¹¹

Two cases of airbag deployment with skin blistering have been reported in the literature based on a PubMed search of articles indexed for MEDLINE using the terms airbag blistering or airbag bullae^12,13; however, the blistering was described in the context of a burn. One case of the effects of airbag deployment residue highlights a patient arriving to the emergency department with erythema and blisters on the hands within 48 hours of airbag deployment in an MVA, and the treatment was standard burn therapy.¹² Another case report described a patient with a second-degree burn with a 12-cm blister occurring on the radial side of the hand and distal forearm following an MVA and airbag deployment, which was treated conservatively.¹³ Cases of thermal burns, chemical burns, and irritant contact dermatitis after airbag deployment have been described in the literature.^{4-6,11,12,14,15} Our patient’s distal right lower leg was covered with a cast for osteomyelitis, and no blisters had developed in this area. It is likely that the transfer of airbag contents occurred during the process of unbuckling his seatbelt, which could explain the bullae that developed on the right flank. Per the Centers for Disease Control and Prevention, individuals should quickly remove clothing and wash their body with large amounts of soap and water following exposure to sodium azide.¹⁶

In 1989, the Federal Motor Vehicle Safety Standard No. 208 (occupant crash protection) became effective, stating all cars must have vehicle crash protection.¹² Prior to 1993, it was reported that there had been no associated chemical injuries with airbag deployment. Subsequently, a 6-month retrospective study in 1993 showed that dermal injuries were found in connection with the presence of sodium hydroxide in automobile airbags.¹² By 2004, it was known that airbags could cause chemical and thermal burns in addition to traumatic injuries from deployment.¹ Since 2007, all motor vehicles have been required to have advanced airbags, which are engineered to sense the presence of passengers and determine if the airbag will deploy, and if so, how much to deploy to minimize airbag-related injury.³

The brand of car that our patient drove during the MVA is one with known airbag recalls due to safety defects; however, the year and actual model of the vehicle are not known, so specific information about the airbag in question is not available. It has been noted that some defective airbag inflators that were exposed to excess moisture during the manufacturing process could explode during deployment, causing shrapnel and airbag rupture, which has been linked to nearly 300 injuries worldwide.¹⁷

Conclusion

It is evident that the use of airbag devices reduces morbidity and mortality due to MVAs.⁹ It also had been reported that up to 96% of airbag-related injuries are relatively minor, which many would argue justifies their use.¹⁸ Furthermore, it has been reported that 99.8% of skin injuries following airbag deployment are minor.¹⁹ In the United States, it is mandated that every vehicle have functional airbags installed.⁸

This case highlights the potential for substantial airbag-induced skin reactions, specifically a bullous reaction, following airbag deployment. The persistent pruritus and lasting postinflammatory hyperpigmentation seen in this case were certainly worrisome for our patient. We also present this case to remind dermatology providers of possible treatment approaches to these skin reactions. Immediate cleansing of the affected areas of skin may help avoid such reactions.

To the Editor:

Wolf isotopic response describes the development of a skin disorder at the site of another healed and unrelated skin disease. Skin disorders presenting as isotopic responses have included inflammatory, malignant, granulomatous, and infectious processes. Discoid lupus erythematosus (DLE) is a rare isotopic response. We report a cutaneous lupus erythematosus–like isotopic response that presented at the site of a recent herpes zoster infection in a liver transplant recipient.

A 74-year-old immunocompromised woman was referred to the dermatology clinic for evaluation of a rash on the right leg. She was being treated with maintenance valganciclovir due to cytomegalovirus viremia, as well as tacrolimus, azathioprine, and prednisone following liver transplantation due to autoimmune hepatitis for 8 months prior to presentation. Eighteen days prior to the current presentation, she was clinically diagnosed with herpes zoster. As the grouped vesicles from the herpes zoster resolved, she developed pink scaly papules in the same distribution as the original vesicular eruption.

Physical examination revealed numerous erythematous, 2- to 3-mm, scaly papules that coalesced into small plaques with serous crusts; they originated above the supragluteal cleft and extended rightward in the L3 and L4 dermatomes to the right knee (Figure 1). A 3-mm punch biopsy specimen was obtained from the right anterior thigh. Histologic analysis revealed interface lymphocytic inflammation with squamatization of basal keratinocytes, basement membrane thickening, and follicular plugging by keratin (Figure 2). There was a moderately intense perivascular and periadnexal inflammatory infiltrate of mature lymphocytes with rare eosinophils within the papillary and superficial reticular dermis. There was no evidence of a viral cytopathic effect, and an immunohistochemical stain for varicella-zoster virus protein was negative. The histologic findings were suggestive of cutaneous involvement by DLE. A diagnosis of a cutaneous lupus erythematosus–like Wolf isotopic response was made, and the patient’s rash resolved with the use of triamcinolone cream 0.1% applied twice daily for 2 weeks. At 6-week follow-up, there were postinflammatory pigmentation changes at the sites of the prior rash and persistent postherpetic neuralgia. Recent antinuclear antibody screening was negative, coupled with the patient’s lack of systemic symptoms and quick resolution of rash, indicating that additional testing for systemic lupus was not warranted.

Wolf isotopic response describes the occurrence of a new skin disorder at the site of a previously healed and unrelated skin disorder. The second disease may appear within days to years after the primary disease subsides and is clearly differentiated from the isomorphic response of the Koebner phenomenon, which describes an established skin disorder appearing at a previously uninvolved anatomic site following trauma.¹ As in our case, the initial cutaneous eruption resulting in a subsequent Wolf isotopic response frequently is herpes zoster and less commonly is herpes simplex virus.² The most common reported isotopic response is a granulomatous reaction.² Rare reports of leukemic infiltration, lymphoma, lichen planus, morphea, reactive perforating collagenosis, psoriasis, discoid lupus, lichen simplex chronicus, contact dermatitis, xanthomatous changes, malignant tumors, cutaneous graft-vs-host disease, pityriasis rosea, erythema annulare centrifugum, and other infectious-based isotopic responses exist.^2-6

Our patient presented with Wolf isotopic response that histologically mimicked DLE. A PubMed search of articles indexed for MEDLINE using the terms isotopic response and lupus revealed only 3 cases of cutaneous lupus erythematosus presenting as an isotopic response in the English-language literature. One of those cases occurred in a patient with preexisting systemic lupus erythematosus, making a diagnosis of Koebner isomorphic phenomenon more appropriate than an isotopic response at the site of prior herpes zoster infection.⁷ The remaining 2 cases were clinically defined DLE lesions occurring at sites of prior infection—cutaneous leishmaniasis and herpes zoster—in patients without a prior history of cutaneous or systemic lupus erythematosus.^8,9 The latter case of DLE-like isotopic response occurring after herpes zoster infection was further complicated by local injections at the zoster site for herpes-related local pain. Injection sites are reported as a distinct nidus for Wolf isotopic response.⁹

The pathogenesis of Wolf isotopic response is unclear. Possible explanations include local interactions between persistent viral particles at prior herpes infection sites, vascular injury, neural injury, and an altered immune response.^1,5,6,10 The destruction of sensory nerve fibers by herpesviruses cause the release of neuropeptides that then modulate the local immune system and angiogenic responses.^5,6 Our patient’s immunocompromised state may have further propagated a local altered immune cell infiltrate at the site of the isotopic response. Despite its unclear etiology, Wolf isotopic response should be considered in the differential diagnosis for any patient who presents with a dermatomal eruption at the site of a prior cutaneous infection, particularly after infection with herpes zoster. Treatment with topical or intralesional corticosteroids usually suffices for inflammatory-based isotopic responses with an excellent prognosis.¹¹

We present a case of a cutaneous lupus erythematosus–like isotopic response that occurred at the site of a recent herpes zoster eruption in an immunocompromised patient without prior history of systemic or cutaneous lupus erythematosus. Clinical recognition of Wolf isotopic response is important for accurate histopathologic diagnosis and management. Continued investigation into the underlying pathogenesis should be performed to fully understand and better treat this process.

To the Editor:

Wolf isotopic response describes the development of a skin disorder at the site of another healed and unrelated skin disease. Skin disorders presenting as isotopic responses have included inflammatory, malignant, granulomatous, and infectious processes. Discoid lupus erythematosus (DLE) is a rare isotopic response. We report a cutaneous lupus erythematosus–like isotopic response that presented at the site of a recent herpes zoster infection in a liver transplant recipient.

A 74-year-old immunocompromised woman was referred to the dermatology clinic for evaluation of a rash on the right leg. She was being treated with maintenance valganciclovir due to cytomegalovirus viremia, as well as tacrolimus, azathioprine, and prednisone following liver transplantation due to autoimmune hepatitis for 8 months prior to presentation. Eighteen days prior to the current presentation, she was clinically diagnosed with herpes zoster. As the grouped vesicles from the herpes zoster resolved, she developed pink scaly papules in the same distribution as the original vesicular eruption.

Physical examination revealed numerous erythematous, 2- to 3-mm, scaly papules that coalesced into small plaques with serous crusts; they originated above the supragluteal cleft and extended rightward in the L3 and L4 dermatomes to the right knee (Figure 1). A 3-mm punch biopsy specimen was obtained from the right anterior thigh. Histologic analysis revealed interface lymphocytic inflammation with squamatization of basal keratinocytes, basement membrane thickening, and follicular plugging by keratin (Figure 2). There was a moderately intense perivascular and periadnexal inflammatory infiltrate of mature lymphocytes with rare eosinophils within the papillary and superficial reticular dermis. There was no evidence of a viral cytopathic effect, and an immunohistochemical stain for varicella-zoster virus protein was negative. The histologic findings were suggestive of cutaneous involvement by DLE. A diagnosis of a cutaneous lupus erythematosus–like Wolf isotopic response was made, and the patient’s rash resolved with the use of triamcinolone cream 0.1% applied twice daily for 2 weeks. At 6-week follow-up, there were postinflammatory pigmentation changes at the sites of the prior rash and persistent postherpetic neuralgia. Recent antinuclear antibody screening was negative, coupled with the patient’s lack of systemic symptoms and quick resolution of rash, indicating that additional testing for systemic lupus was not warranted.

Wolf isotopic response describes the occurrence of a new skin disorder at the site of a previously healed and unrelated skin disorder. The second disease may appear within days to years after the primary disease subsides and is clearly differentiated from the isomorphic response of the Koebner phenomenon, which describes an established skin disorder appearing at a previously uninvolved anatomic site following trauma.¹ As in our case, the initial cutaneous eruption resulting in a subsequent Wolf isotopic response frequently is herpes zoster and less commonly is herpes simplex virus.² The most common reported isotopic response is a granulomatous reaction.² Rare reports of leukemic infiltration, lymphoma, lichen planus, morphea, reactive perforating collagenosis, psoriasis, discoid lupus, lichen simplex chronicus, contact dermatitis, xanthomatous changes, malignant tumors, cutaneous graft-vs-host disease, pityriasis rosea, erythema annulare centrifugum, and other infectious-based isotopic responses exist.^2-6

Our patient presented with Wolf isotopic response that histologically mimicked DLE. A PubMed search of articles indexed for MEDLINE using the terms isotopic response and lupus revealed only 3 cases of cutaneous lupus erythematosus presenting as an isotopic response in the English-language literature. One of those cases occurred in a patient with preexisting systemic lupus erythematosus, making a diagnosis of Koebner isomorphic phenomenon more appropriate than an isotopic response at the site of prior herpes zoster infection.⁷ The remaining 2 cases were clinically defined DLE lesions occurring at sites of prior infection—cutaneous leishmaniasis and herpes zoster—in patients without a prior history of cutaneous or systemic lupus erythematosus.^8,9 The latter case of DLE-like isotopic response occurring after herpes zoster infection was further complicated by local injections at the zoster site for herpes-related local pain. Injection sites are reported as a distinct nidus for Wolf isotopic response.⁹

The pathogenesis of Wolf isotopic response is unclear. Possible explanations include local interactions between persistent viral particles at prior herpes infection sites, vascular injury, neural injury, and an altered immune response.^1,5,6,10 The destruction of sensory nerve fibers by herpesviruses cause the release of neuropeptides that then modulate the local immune system and angiogenic responses.^5,6 Our patient’s immunocompromised state may have further propagated a local altered immune cell infiltrate at the site of the isotopic response. Despite its unclear etiology, Wolf isotopic response should be considered in the differential diagnosis for any patient who presents with a dermatomal eruption at the site of a prior cutaneous infection, particularly after infection with herpes zoster. Treatment with topical or intralesional corticosteroids usually suffices for inflammatory-based isotopic responses with an excellent prognosis.¹¹

We present a case of a cutaneous lupus erythematosus–like isotopic response that occurred at the site of a recent herpes zoster eruption in an immunocompromised patient without prior history of systemic or cutaneous lupus erythematosus. Clinical recognition of Wolf isotopic response is important for accurate histopathologic diagnosis and management. Continued investigation into the underlying pathogenesis should be performed to fully understand and better treat this process.

To the Editor:

Wolf isotopic response describes the development of a skin disorder at the site of another healed and unrelated skin disease. Skin disorders presenting as isotopic responses have included inflammatory, malignant, granulomatous, and infectious processes. Discoid lupus erythematosus (DLE) is a rare isotopic response. We report a cutaneous lupus erythematosus–like isotopic response that presented at the site of a recent herpes zoster infection in a liver transplant recipient.

A 74-year-old immunocompromised woman was referred to the dermatology clinic for evaluation of a rash on the right leg. She was being treated with maintenance valganciclovir due to cytomegalovirus viremia, as well as tacrolimus, azathioprine, and prednisone following liver transplantation due to autoimmune hepatitis for 8 months prior to presentation. Eighteen days prior to the current presentation, she was clinically diagnosed with herpes zoster. As the grouped vesicles from the herpes zoster resolved, she developed pink scaly papules in the same distribution as the original vesicular eruption.

Physical examination revealed numerous erythematous, 2- to 3-mm, scaly papules that coalesced into small plaques with serous crusts; they originated above the supragluteal cleft and extended rightward in the L3 and L4 dermatomes to the right knee (Figure 1). A 3-mm punch biopsy specimen was obtained from the right anterior thigh. Histologic analysis revealed interface lymphocytic inflammation with squamatization of basal keratinocytes, basement membrane thickening, and follicular plugging by keratin (Figure 2). There was a moderately intense perivascular and periadnexal inflammatory infiltrate of mature lymphocytes with rare eosinophils within the papillary and superficial reticular dermis. There was no evidence of a viral cytopathic effect, and an immunohistochemical stain for varicella-zoster virus protein was negative. The histologic findings were suggestive of cutaneous involvement by DLE. A diagnosis of a cutaneous lupus erythematosus–like Wolf isotopic response was made, and the patient’s rash resolved with the use of triamcinolone cream 0.1% applied twice daily for 2 weeks. At 6-week follow-up, there were postinflammatory pigmentation changes at the sites of the prior rash and persistent postherpetic neuralgia. Recent antinuclear antibody screening was negative, coupled with the patient’s lack of systemic symptoms and quick resolution of rash, indicating that additional testing for systemic lupus was not warranted.

Wolf isotopic response describes the occurrence of a new skin disorder at the site of a previously healed and unrelated skin disorder. The second disease may appear within days to years after the primary disease subsides and is clearly differentiated from the isomorphic response of the Koebner phenomenon, which describes an established skin disorder appearing at a previously uninvolved anatomic site following trauma.¹ As in our case, the initial cutaneous eruption resulting in a subsequent Wolf isotopic response frequently is herpes zoster and less commonly is herpes simplex virus.² The most common reported isotopic response is a granulomatous reaction.² Rare reports of leukemic infiltration, lymphoma, lichen planus, morphea, reactive perforating collagenosis, psoriasis, discoid lupus, lichen simplex chronicus, contact dermatitis, xanthomatous changes, malignant tumors, cutaneous graft-vs-host disease, pityriasis rosea, erythema annulare centrifugum, and other infectious-based isotopic responses exist.^2-6

Our patient presented with Wolf isotopic response that histologically mimicked DLE. A PubMed search of articles indexed for MEDLINE using the terms isotopic response and lupus revealed only 3 cases of cutaneous lupus erythematosus presenting as an isotopic response in the English-language literature. One of those cases occurred in a patient with preexisting systemic lupus erythematosus, making a diagnosis of Koebner isomorphic phenomenon more appropriate than an isotopic response at the site of prior herpes zoster infection.⁷ The remaining 2 cases were clinically defined DLE lesions occurring at sites of prior infection—cutaneous leishmaniasis and herpes zoster—in patients without a prior history of cutaneous or systemic lupus erythematosus.^8,9 The latter case of DLE-like isotopic response occurring after herpes zoster infection was further complicated by local injections at the zoster site for herpes-related local pain. Injection sites are reported as a distinct nidus for Wolf isotopic response.⁹

The pathogenesis of Wolf isotopic response is unclear. Possible explanations include local interactions between persistent viral particles at prior herpes infection sites, vascular injury, neural injury, and an altered immune response.^1,5,6,10 The destruction of sensory nerve fibers by herpesviruses cause the release of neuropeptides that then modulate the local immune system and angiogenic responses.^5,6 Our patient’s immunocompromised state may have further propagated a local altered immune cell infiltrate at the site of the isotopic response. Despite its unclear etiology, Wolf isotopic response should be considered in the differential diagnosis for any patient who presents with a dermatomal eruption at the site of a prior cutaneous infection, particularly after infection with herpes zoster. Treatment with topical or intralesional corticosteroids usually suffices for inflammatory-based isotopic responses with an excellent prognosis.¹¹

We present a case of a cutaneous lupus erythematosus–like isotopic response that occurred at the site of a recent herpes zoster eruption in an immunocompromised patient without prior history of systemic or cutaneous lupus erythematosus. Clinical recognition of Wolf isotopic response is important for accurate histopathologic diagnosis and management. Continued investigation into the underlying pathogenesis should be performed to fully understand and better treat this process.

Dupilumab is a humanized monoclonal antibody approved by the US Food and Drug Administration (FDA) for the treatment of moderate to severe atopic dermatitis. Through inhibition of the IL-4R α subunit, it prevents activation of the IL-4/IL-13 signaling cascade. This dampens the T _H 2 inflammatory response, thereby improving the symptoms associated with atopic dermatitis. ^1,2 Recent literature suggests that dupilumab may be useful in the treatment of other chronic dermatologic conditions, including allergic contact dermatitis (ACD) refractory to allergen avoidance and other treatments. Herein, we provide an overview of ACD, the role that dupilumab may play in its management, and its impact on patch testing results.

Pathogenesis of ACD

Allergic contact dermatitis is a cell-mediated type IV hypersensitivity reaction that develops through 2 distinct stages. In the sensitization phase, an allergen penetrates the skin and subsequently is engulfed by a cutaneous antigen-presenting cell. The allergen is then combined with a peptide to form a complex that is presented to naïve T lymphocytes in regional lymph nodes. The result is clonal expansion of a T-cell population that recognizes the allergen. In the elicitation phase, repeat exposure to the allergen leads to the recruitment of primed T cells to the skin, followed by cytokine release, inflammation, and resultant dermatitis.³

Historically, ACD was thought to be primarily driven by the T_H1 inflammatory response; however, it is now known that T_H2, T_H9, T_H17, and T_H22 also may play a role in its pathogenesis.^4,5 Another key finding is that the immune response in ACD appears to be at least partially allergen specific. Molecular profiling has revealed that nickel primarily induces a T_H1/T_H17 response, while allergens such as fragrance and rubber primarily induce a T_H2 response.⁴

Management of ACD

Allergen avoidance is the mainstay of ACD treatment; however, in some patients, this approach does not always improve symptoms. In addition, eliminating the source of the allergen may not be possible in those with certain occupational, environmental, or medical exposures.

There are no FDA-approved treatments for ACD. When allergen avoidance alone is insufficient, first-line pharmacologic therapy typically includes topical or oral corticosteroids, the choice of which depends on the extent and severity of the dermatitis; however, a steroid-sparing agent often is preferred to avoid the unfavorable effects of long-term steroid use. Other systemic treatments for ACD include methotrexate, cyclosporine, mycophenolate mofetil, and azathioprine.⁶ These agents are used for severe ACD and typically are chosen as a last resort due to their immunosuppressive activity.

Phototherapy is another option, often as an adjunct to other therapies. Narrowband UVB and psoralen plus UVA have both been used. Psoralen plus UVA tends to have more side effects; therefore, narrowband UVB often is preferred.^7,8

Use of Dupilumab in ACD

Biologics are unique, as they can target a single step in the immune response to improve a wide variety of symptoms. Research investigating their role as a treatment modality for ACD is still evolving alongside our increasing knowledge of its pathophysiology.⁹ Of note, studies examining the anti–IL-17 biologic secukinumab revealed it to be ineffective against ACD,^10,11 which suggests that targeting specific immune components may not always result in improvement of ACD symptoms, likely because its pathophysiology involves several pathways.

There have been multiple reports demonstrating the effectiveness of dupilumab in the treatment of ACD (eTable).^12-20 The findings from these studies show that dupilumab can improve recalcitrant dermatitis caused by a broad range of contact allergens, including nickel. This highlights its ability to improve ACD caused by allergens with a T_H1 bias, despite its primarily T_H2-dampening effects. Notably, several studies have reported successful use of dupilumab for systemic ACD.^12,18 In addition, dupilumab may be able to improve symptoms of ACD in as little as 1 to 4 weeks. Unlike some systemic therapies for ACD, dupilumab also benefits from its lack of notable immunosuppressive effects.⁹ A phase 4 clinical trial at Brigham and Women’s Hospital (Boston, Massachusetts) is recruiting participants, with a primary goal of investigating dupilumab’s impact on ACD in patients who have not improved despite allergen avoidance (ClinicalTrials.gov identifier NCT03935971).

There are a few potential disadvantages to dupilumab. Because it is not yet FDA approved for the treatment of ACD, insurance companies may deny coverage, making it likely to be unaffordable for most patients. Furthermore, the side-effect profile has not been fully characterized. In addition to ocular adverse effects, a growing number of studies have reported face and neck erythema after starting dupilumab. Although the cause is unclear, one theory is that the inhibition of IL-4/IL-13 leads to T_H1/T_H17 polarization, thereby worsening ACD caused by allergens that activate a T_H1-predominant response.²¹ Finally, not all cases of ACD respond to dupilumab.²²

Patch Testing While on Dupilumab

Diagnosing ACD is a challenging process. An accurate history and physical examination are critical, and patch testing remains the gold standard when it comes to identifying the source of the contact allergen(s).

There is ongoing debate among contact dermatitis experts regarding the diagnostic accuracy of patch testing for those on immunomodulators or immunosuppressants, as these medications can dampen positive results and increase the risk for false-negative readings.²³ Consequently, some have questioned whether patch testing on dupilumab is accurate or feasible.²⁴ Contact dermatitis experts have examined patch testing results before and after initiation of dupilumab to further investigate. Puza and Atwater²⁵ established that patients are able to mount a positive patch test reaction while on dupilumab. Moreover, a retrospective review by Raffi et al²⁶ found that out of 125 before therapy/on therapy patch test pairs, only 13 were lost after administration of dupilumab. Although this would suggest that dupilumab has little impact on patch testing, Jo et al²⁷ found in a systematic review that patch test reactions may remain positive, change to negative, or become newly positive after dupilumab initiation.

This inconsistency in results may relate to the allergen-specific pathogenesis of ACD—one allergen may have a different response to the mechanism of dupilumab than another.^28,29 More recently, de Wijs et al³⁰ reported a series of 20 patients in whom more than two-thirds of prior positive patch test reactions were lost after retesting on dupilumab; there were no clear trends according to the immune polarity of the allergens. This finding suggests that patient-specific factors also should be considered, as this too could have an impact on the reliability of patch test findings after starting dupilumab.²⁹

Final Interpretation

Given its overall excellent safety profile, dupilumab may be a feasible off-label option for patients with ACD that does not respond to allergen avoidance or for those who experience adverse effects from traditional therapies; however, it remains difficult to obtain through insurance because it is not yet FDA approved for ACD. Likewise, its impact on the accuracy of patch testing is not yet well defined. Further investigations are needed to elucidate the pathophysiology of ACD and to guide further use of dupilumab in its treatment.

Dupilumab is a humanized monoclonal antibody approved by the US Food and Drug Administration (FDA) for the treatment of moderate to severe atopic dermatitis. Through inhibition of the IL-4R α subunit, it prevents activation of the IL-4/IL-13 signaling cascade. This dampens the T _H 2 inflammatory response, thereby improving the symptoms associated with atopic dermatitis. ^1,2 Recent literature suggests that dupilumab may be useful in the treatment of other chronic dermatologic conditions, including allergic contact dermatitis (ACD) refractory to allergen avoidance and other treatments. Herein, we provide an overview of ACD, the role that dupilumab may play in its management, and its impact on patch testing results.

Pathogenesis of ACD

Allergic contact dermatitis is a cell-mediated type IV hypersensitivity reaction that develops through 2 distinct stages. In the sensitization phase, an allergen penetrates the skin and subsequently is engulfed by a cutaneous antigen-presenting cell. The allergen is then combined with a peptide to form a complex that is presented to naïve T lymphocytes in regional lymph nodes. The result is clonal expansion of a T-cell population that recognizes the allergen. In the elicitation phase, repeat exposure to the allergen leads to the recruitment of primed T cells to the skin, followed by cytokine release, inflammation, and resultant dermatitis.³

Historically, ACD was thought to be primarily driven by the T_H1 inflammatory response; however, it is now known that T_H2, T_H9, T_H17, and T_H22 also may play a role in its pathogenesis.^4,5 Another key finding is that the immune response in ACD appears to be at least partially allergen specific. Molecular profiling has revealed that nickel primarily induces a T_H1/T_H17 response, while allergens such as fragrance and rubber primarily induce a T_H2 response.⁴

Management of ACD

Allergen avoidance is the mainstay of ACD treatment; however, in some patients, this approach does not always improve symptoms. In addition, eliminating the source of the allergen may not be possible in those with certain occupational, environmental, or medical exposures.

There are no FDA-approved treatments for ACD. When allergen avoidance alone is insufficient, first-line pharmacologic therapy typically includes topical or oral corticosteroids, the choice of which depends on the extent and severity of the dermatitis; however, a steroid-sparing agent often is preferred to avoid the unfavorable effects of long-term steroid use. Other systemic treatments for ACD include methotrexate, cyclosporine, mycophenolate mofetil, and azathioprine.⁶ These agents are used for severe ACD and typically are chosen as a last resort due to their immunosuppressive activity.

Phototherapy is another option, often as an adjunct to other therapies. Narrowband UVB and psoralen plus UVA have both been used. Psoralen plus UVA tends to have more side effects; therefore, narrowband UVB often is preferred.^7,8

Use of Dupilumab in ACD

Biologics are unique, as they can target a single step in the immune response to improve a wide variety of symptoms. Research investigating their role as a treatment modality for ACD is still evolving alongside our increasing knowledge of its pathophysiology.⁹ Of note, studies examining the anti–IL-17 biologic secukinumab revealed it to be ineffective against ACD,^10,11 which suggests that targeting specific immune components may not always result in improvement of ACD symptoms, likely because its pathophysiology involves several pathways.

There have been multiple reports demonstrating the effectiveness of dupilumab in the treatment of ACD (eTable).^12-20 The findings from these studies show that dupilumab can improve recalcitrant dermatitis caused by a broad range of contact allergens, including nickel. This highlights its ability to improve ACD caused by allergens with a T_H1 bias, despite its primarily T_H2-dampening effects. Notably, several studies have reported successful use of dupilumab for systemic ACD.^12,18 In addition, dupilumab may be able to improve symptoms of ACD in as little as 1 to 4 weeks. Unlike some systemic therapies for ACD, dupilumab also benefits from its lack of notable immunosuppressive effects.⁹ A phase 4 clinical trial at Brigham and Women’s Hospital (Boston, Massachusetts) is recruiting participants, with a primary goal of investigating dupilumab’s impact on ACD in patients who have not improved despite allergen avoidance (ClinicalTrials.gov identifier NCT03935971).

There are a few potential disadvantages to dupilumab. Because it is not yet FDA approved for the treatment of ACD, insurance companies may deny coverage, making it likely to be unaffordable for most patients. Furthermore, the side-effect profile has not been fully characterized. In addition to ocular adverse effects, a growing number of studies have reported face and neck erythema after starting dupilumab. Although the cause is unclear, one theory is that the inhibition of IL-4/IL-13 leads to T_H1/T_H17 polarization, thereby worsening ACD caused by allergens that activate a T_H1-predominant response.²¹ Finally, not all cases of ACD respond to dupilumab.²²

Patch Testing While on Dupilumab

Diagnosing ACD is a challenging process. An accurate history and physical examination are critical, and patch testing remains the gold standard when it comes to identifying the source of the contact allergen(s).

There is ongoing debate among contact dermatitis experts regarding the diagnostic accuracy of patch testing for those on immunomodulators or immunosuppressants, as these medications can dampen positive results and increase the risk for false-negative readings.²³ Consequently, some have questioned whether patch testing on dupilumab is accurate or feasible.²⁴ Contact dermatitis experts have examined patch testing results before and after initiation of dupilumab to further investigate. Puza and Atwater²⁵ established that patients are able to mount a positive patch test reaction while on dupilumab. Moreover, a retrospective review by Raffi et al²⁶ found that out of 125 before therapy/on therapy patch test pairs, only 13 were lost after administration of dupilumab. Although this would suggest that dupilumab has little impact on patch testing, Jo et al²⁷ found in a systematic review that patch test reactions may remain positive, change to negative, or become newly positive after dupilumab initiation.

This inconsistency in results may relate to the allergen-specific pathogenesis of ACD—one allergen may have a different response to the mechanism of dupilumab than another.^28,29 More recently, de Wijs et al³⁰ reported a series of 20 patients in whom more than two-thirds of prior positive patch test reactions were lost after retesting on dupilumab; there were no clear trends according to the immune polarity of the allergens. This finding suggests that patient-specific factors also should be considered, as this too could have an impact on the reliability of patch test findings after starting dupilumab.²⁹

Final Interpretation

Given its overall excellent safety profile, dupilumab may be a feasible off-label option for patients with ACD that does not respond to allergen avoidance or for those who experience adverse effects from traditional therapies; however, it remains difficult to obtain through insurance because it is not yet FDA approved for ACD. Likewise, its impact on the accuracy of patch testing is not yet well defined. Further investigations are needed to elucidate the pathophysiology of ACD and to guide further use of dupilumab in its treatment.

Dupilumab is a humanized monoclonal antibody approved by the US Food and Drug Administration (FDA) for the treatment of moderate to severe atopic dermatitis. Through inhibition of the IL-4R α subunit, it prevents activation of the IL-4/IL-13 signaling cascade. This dampens the T _H 2 inflammatory response, thereby improving the symptoms associated with atopic dermatitis. ^1,2 Recent literature suggests that dupilumab may be useful in the treatment of other chronic dermatologic conditions, including allergic contact dermatitis (ACD) refractory to allergen avoidance and other treatments. Herein, we provide an overview of ACD, the role that dupilumab may play in its management, and its impact on patch testing results.

Pathogenesis of ACD

Allergic contact dermatitis is a cell-mediated type IV hypersensitivity reaction that develops through 2 distinct stages. In the sensitization phase, an allergen penetrates the skin and subsequently is engulfed by a cutaneous antigen-presenting cell. The allergen is then combined with a peptide to form a complex that is presented to naïve T lymphocytes in regional lymph nodes. The result is clonal expansion of a T-cell population that recognizes the allergen. In the elicitation phase, repeat exposure to the allergen leads to the recruitment of primed T cells to the skin, followed by cytokine release, inflammation, and resultant dermatitis.³

Historically, ACD was thought to be primarily driven by the T_H1 inflammatory response; however, it is now known that T_H2, T_H9, T_H17, and T_H22 also may play a role in its pathogenesis.^4,5 Another key finding is that the immune response in ACD appears to be at least partially allergen specific. Molecular profiling has revealed that nickel primarily induces a T_H1/T_H17 response, while allergens such as fragrance and rubber primarily induce a T_H2 response.⁴

Management of ACD

Allergen avoidance is the mainstay of ACD treatment; however, in some patients, this approach does not always improve symptoms. In addition, eliminating the source of the allergen may not be possible in those with certain occupational, environmental, or medical exposures.

There are no FDA-approved treatments for ACD. When allergen avoidance alone is insufficient, first-line pharmacologic therapy typically includes topical or oral corticosteroids, the choice of which depends on the extent and severity of the dermatitis; however, a steroid-sparing agent often is preferred to avoid the unfavorable effects of long-term steroid use. Other systemic treatments for ACD include methotrexate, cyclosporine, mycophenolate mofetil, and azathioprine.⁶ These agents are used for severe ACD and typically are chosen as a last resort due to their immunosuppressive activity.

Phototherapy is another option, often as an adjunct to other therapies. Narrowband UVB and psoralen plus UVA have both been used. Psoralen plus UVA tends to have more side effects; therefore, narrowband UVB often is preferred.^7,8

Use of Dupilumab in ACD

Biologics are unique, as they can target a single step in the immune response to improve a wide variety of symptoms. Research investigating their role as a treatment modality for ACD is still evolving alongside our increasing knowledge of its pathophysiology.⁹ Of note, studies examining the anti–IL-17 biologic secukinumab revealed it to be ineffective against ACD,^10,11 which suggests that targeting specific immune components may not always result in improvement of ACD symptoms, likely because its pathophysiology involves several pathways.

There have been multiple reports demonstrating the effectiveness of dupilumab in the treatment of ACD (eTable).^12-20 The findings from these studies show that dupilumab can improve recalcitrant dermatitis caused by a broad range of contact allergens, including nickel. This highlights its ability to improve ACD caused by allergens with a T_H1 bias, despite its primarily T_H2-dampening effects. Notably, several studies have reported successful use of dupilumab for systemic ACD.^12,18 In addition, dupilumab may be able to improve symptoms of ACD in as little as 1 to 4 weeks. Unlike some systemic therapies for ACD, dupilumab also benefits from its lack of notable immunosuppressive effects.⁹ A phase 4 clinical trial at Brigham and Women’s Hospital (Boston, Massachusetts) is recruiting participants, with a primary goal of investigating dupilumab’s impact on ACD in patients who have not improved despite allergen avoidance (ClinicalTrials.gov identifier NCT03935971).

There are a few potential disadvantages to dupilumab. Because it is not yet FDA approved for the treatment of ACD, insurance companies may deny coverage, making it likely to be unaffordable for most patients. Furthermore, the side-effect profile has not been fully characterized. In addition to ocular adverse effects, a growing number of studies have reported face and neck erythema after starting dupilumab. Although the cause is unclear, one theory is that the inhibition of IL-4/IL-13 leads to T_H1/T_H17 polarization, thereby worsening ACD caused by allergens that activate a T_H1-predominant response.²¹ Finally, not all cases of ACD respond to dupilumab.²²

Patch Testing While on Dupilumab

Diagnosing ACD is a challenging process. An accurate history and physical examination are critical, and patch testing remains the gold standard when it comes to identifying the source of the contact allergen(s).

There is ongoing debate among contact dermatitis experts regarding the diagnostic accuracy of patch testing for those on immunomodulators or immunosuppressants, as these medications can dampen positive results and increase the risk for false-negative readings.²³ Consequently, some have questioned whether patch testing on dupilumab is accurate or feasible.²⁴ Contact dermatitis experts have examined patch testing results before and after initiation of dupilumab to further investigate. Puza and Atwater²⁵ established that patients are able to mount a positive patch test reaction while on dupilumab. Moreover, a retrospective review by Raffi et al²⁶ found that out of 125 before therapy/on therapy patch test pairs, only 13 were lost after administration of dupilumab. Although this would suggest that dupilumab has little impact on patch testing, Jo et al²⁷ found in a systematic review that patch test reactions may remain positive, change to negative, or become newly positive after dupilumab initiation.

This inconsistency in results may relate to the allergen-specific pathogenesis of ACD—one allergen may have a different response to the mechanism of dupilumab than another.^28,29 More recently, de Wijs et al³⁰ reported a series of 20 patients in whom more than two-thirds of prior positive patch test reactions were lost after retesting on dupilumab; there were no clear trends according to the immune polarity of the allergens. This finding suggests that patient-specific factors also should be considered, as this too could have an impact on the reliability of patch test findings after starting dupilumab.²⁹

Final Interpretation

Given its overall excellent safety profile, dupilumab may be a feasible off-label option for patients with ACD that does not respond to allergen avoidance or for those who experience adverse effects from traditional therapies; however, it remains difficult to obtain through insurance because it is not yet FDA approved for ACD. Likewise, its impact on the accuracy of patch testing is not yet well defined. Further investigations are needed to elucidate the pathophysiology of ACD and to guide further use of dupilumab in its treatment.

There are limited clinical data concerning inpatient and emergency department (ED) dermatologic consultations. The indications for these consultations vary widely, but in one study (N=271), it was found that 21% of inpatient consultations were for contact dermatitis and 10% were for drug eruptions.¹ In the same study, 77% of patients who required a dermatology consultation eventually were given a different diagnosis or change in treatment after consultation. For example, of all consultations for suspected cellulitis, only 10% were confirmed after dermatology evaluation.¹

Hospitalists and emergency physicians continue to struggle with the assessment of dermatologic conditions, often consulting dermatology whenever a patient has a “rash” or skin concern. Dermatology is still not emphasized in medical education and often is taught to most medical students in an abbreviated fashion, which results in physicians feeling ill-equipped to deal with any dermatologic condition—either mundane or potentially life-threatening. A study in 2016 showed that a monthly lecture series given to hospitalists over the course of 5 years did not improve diagnostic accuracy in patients who were admitted with skin manifestations.² This further shows that there is a need for dermatologic experts in the hospital.

We need to develop better guidelines for physicians in the ED and on inpatient units to guide them on appropriate use of dermatologic consultation outside the ambulatory office and the clinic. A 2013 study showed that patients often were discharged immediately after a dermatologic consultation, furthering our hypothesis that many inpatient consultations can be delayed until after discharge.³

In an era in which medical costs are soaring and there is constant surveillance for ways to reduce costs without impairing quality of care, limiting unnecessary specialty consultations should be embraced. In 2009, $1.8 billion in Medicare claims was paid for dermatology-related admissions.³ A substantial savings to Medicare consulting fees for certain diagnoses, such as cellulitis or contact dermatitis, could be realized if patients were referred for outpatient assessment and treatment. In a study of 271 consultations, 54 patients also had a skin biopsy, which further increases dollars spent on inpatient care and is (usually) something that can be performed in the outpatient setting.¹ In another study, the more common recommended treatments were topical corticosteroids and supportive educational measures for patients and hospital staff,³ which further substantiates that most dermatology consultations are not truly emergent and can wait for outpatient consultation.

In addition, we are dealing with the COVID-19 pandemic in our hospitals and EDs. Many physicians, including dermatologists, would prefer to avoid unnecessary exposure to SARS-CoV-2 on inpatient units and in the ED. It certainly would be preferable to require consultants to come in to evaluate patients only when they truly need to be seen while in the hospital.

There also is limited dermatology training in other specialties, and the dermatology team can help fill this gap with educational programs and one-on-one teaching. Hospital teams have signaled this need, but there has been limited success with multiple teaching opportunities.⁴

We believe that this need for inpatient dermatology services can be filled with the newer subspecialty of hospital dermatology, which is not commonly present at most hospitals; a reason why the subspecialty has not been more popular is that there are few available data in the form of randomized clinical trials that can guide inpatient dermatologists with the care of rare hospital skin diseases.⁵ Having a dermatologic hospitalist available might allow for patients to be seen more readily, which ultimately will save lives and health care dollars and would increase real-time teaching and education for house staff, nursing, and attendings at the bedside.

In a 2018 article,⁶ it was postulated that quicker diagnosis of pseudocellulitis and initiation of antibiotics to treat this condition would save the US health care system $210 million annually. We believe that pseudocellulitis would be best evaluated by inpatient dermatology teams, thereby avoiding costly dermatologic consultations, at an average rate of $138.89.⁶

Morbilliform drug eruptions are among the most common skin conditions seen in the hospital; approximately 95% of cases are an uncomplicated reaction to a medication or virus. Data show that many of these consultations might be unnecessary.⁷

Our institution (Hackensack University Medical Center, New Jersey) is a tertiary hospital that also is connected with a major cancer center. Given this connection, skin eruptions due to chemotherapy and radiation are common. The treatment of drug eruptions, graft-vs-host disease, and other oncologic or drug-related eruptions should be within the scope of practice of our hospitalists, but these cases frequently involve dermatologic consultation.

We constructed a consultation flowchart (Figure) to help guide the triage of patients in need of dermatologic evaluation by inpatient teams and possibly to avoid unnecessary consultation fees. The manner in which this—or any flowchart or teaching aid—is conveyed to hospital personnel is critical so that these tools are not perceived as patronizing or confrontational. In our flowchart, we list emergent dermatologic conditions that we believe are appropriate for dermatology consultation including erythrodermic psoriasis, bullous pemphigoid flare, and Stevens-Johnson syndrome/toxic epidermal necrolysis.

We believe that the flowchart can educate inpatient medical teams about appropriate dermatology consultation. Use of the flowchart also may decrease unnecessary consultations, which ultimately will lower health care spending overall.

There are limited clinical data concerning inpatient and emergency department (ED) dermatologic consultations. The indications for these consultations vary widely, but in one study (N=271), it was found that 21% of inpatient consultations were for contact dermatitis and 10% were for drug eruptions.¹ In the same study, 77% of patients who required a dermatology consultation eventually were given a different diagnosis or change in treatment after consultation. For example, of all consultations for suspected cellulitis, only 10% were confirmed after dermatology evaluation.¹

Hospitalists and emergency physicians continue to struggle with the assessment of dermatologic conditions, often consulting dermatology whenever a patient has a “rash” or skin concern. Dermatology is still not emphasized in medical education and often is taught to most medical students in an abbreviated fashion, which results in physicians feeling ill-equipped to deal with any dermatologic condition—either mundane or potentially life-threatening. A study in 2016 showed that a monthly lecture series given to hospitalists over the course of 5 years did not improve diagnostic accuracy in patients who were admitted with skin manifestations.² This further shows that there is a need for dermatologic experts in the hospital.

We need to develop better guidelines for physicians in the ED and on inpatient units to guide them on appropriate use of dermatologic consultation outside the ambulatory office and the clinic. A 2013 study showed that patients often were discharged immediately after a dermatologic consultation, furthering our hypothesis that many inpatient consultations can be delayed until after discharge.³

In an era in which medical costs are soaring and there is constant surveillance for ways to reduce costs without impairing quality of care, limiting unnecessary specialty consultations should be embraced. In 2009, $1.8 billion in Medicare claims was paid for dermatology-related admissions.³ A substantial savings to Medicare consulting fees for certain diagnoses, such as cellulitis or contact dermatitis, could be realized if patients were referred for outpatient assessment and treatment. In a study of 271 consultations, 54 patients also had a skin biopsy, which further increases dollars spent on inpatient care and is (usually) something that can be performed in the outpatient setting.¹ In another study, the more common recommended treatments were topical corticosteroids and supportive educational measures for patients and hospital staff,³ which further substantiates that most dermatology consultations are not truly emergent and can wait for outpatient consultation.

In addition, we are dealing with the COVID-19 pandemic in our hospitals and EDs. Many physicians, including dermatologists, would prefer to avoid unnecessary exposure to SARS-CoV-2 on inpatient units and in the ED. It certainly would be preferable to require consultants to come in to evaluate patients only when they truly need to be seen while in the hospital.

There also is limited dermatology training in other specialties, and the dermatology team can help fill this gap with educational programs and one-on-one teaching. Hospital teams have signaled this need, but there has been limited success with multiple teaching opportunities.⁴

We believe that this need for inpatient dermatology services can be filled with the newer subspecialty of hospital dermatology, which is not commonly present at most hospitals; a reason why the subspecialty has not been more popular is that there are few available data in the form of randomized clinical trials that can guide inpatient dermatologists with the care of rare hospital skin diseases.⁵ Having a dermatologic hospitalist available might allow for patients to be seen more readily, which ultimately will save lives and health care dollars and would increase real-time teaching and education for house staff, nursing, and attendings at the bedside.

In a 2018 article,⁶ it was postulated that quicker diagnosis of pseudocellulitis and initiation of antibiotics to treat this condition would save the US health care system $210 million annually. We believe that pseudocellulitis would be best evaluated by inpatient dermatology teams, thereby avoiding costly dermatologic consultations, at an average rate of $138.89.⁶

Morbilliform drug eruptions are among the most common skin conditions seen in the hospital; approximately 95% of cases are an uncomplicated reaction to a medication or virus. Data show that many of these consultations might be unnecessary.⁷

Our institution (Hackensack University Medical Center, New Jersey) is a tertiary hospital that also is connected with a major cancer center. Given this connection, skin eruptions due to chemotherapy and radiation are common. The treatment of drug eruptions, graft-vs-host disease, and other oncologic or drug-related eruptions should be within the scope of practice of our hospitalists, but these cases frequently involve dermatologic consultation.

We constructed a consultation flowchart (Figure) to help guide the triage of patients in need of dermatologic evaluation by inpatient teams and possibly to avoid unnecessary consultation fees. The manner in which this—or any flowchart or teaching aid—is conveyed to hospital personnel is critical so that these tools are not perceived as patronizing or confrontational. In our flowchart, we list emergent dermatologic conditions that we believe are appropriate for dermatology consultation including erythrodermic psoriasis, bullous pemphigoid flare, and Stevens-Johnson syndrome/toxic epidermal necrolysis.

We believe that the flowchart can educate inpatient medical teams about appropriate dermatology consultation. Use of the flowchart also may decrease unnecessary consultations, which ultimately will lower health care spending overall.

There are limited clinical data concerning inpatient and emergency department (ED) dermatologic consultations. The indications for these consultations vary widely, but in one study (N=271), it was found that 21% of inpatient consultations were for contact dermatitis and 10% were for drug eruptions.¹ In the same study, 77% of patients who required a dermatology consultation eventually were given a different diagnosis or change in treatment after consultation. For example, of all consultations for suspected cellulitis, only 10% were confirmed after dermatology evaluation.¹

Hospitalists and emergency physicians continue to struggle with the assessment of dermatologic conditions, often consulting dermatology whenever a patient has a “rash” or skin concern. Dermatology is still not emphasized in medical education and often is taught to most medical students in an abbreviated fashion, which results in physicians feeling ill-equipped to deal with any dermatologic condition—either mundane or potentially life-threatening. A study in 2016 showed that a monthly lecture series given to hospitalists over the course of 5 years did not improve diagnostic accuracy in patients who were admitted with skin manifestations.² This further shows that there is a need for dermatologic experts in the hospital.

We need to develop better guidelines for physicians in the ED and on inpatient units to guide them on appropriate use of dermatologic consultation outside the ambulatory office and the clinic. A 2013 study showed that patients often were discharged immediately after a dermatologic consultation, furthering our hypothesis that many inpatient consultations can be delayed until after discharge.³

In an era in which medical costs are soaring and there is constant surveillance for ways to reduce costs without impairing quality of care, limiting unnecessary specialty consultations should be embraced. In 2009, $1.8 billion in Medicare claims was paid for dermatology-related admissions.³ A substantial savings to Medicare consulting fees for certain diagnoses, such as cellulitis or contact dermatitis, could be realized if patients were referred for outpatient assessment and treatment. In a study of 271 consultations, 54 patients also had a skin biopsy, which further increases dollars spent on inpatient care and is (usually) something that can be performed in the outpatient setting.¹ In another study, the more common recommended treatments were topical corticosteroids and supportive educational measures for patients and hospital staff,³ which further substantiates that most dermatology consultations are not truly emergent and can wait for outpatient consultation.

In addition, we are dealing with the COVID-19 pandemic in our hospitals and EDs. Many physicians, including dermatologists, would prefer to avoid unnecessary exposure to SARS-CoV-2 on inpatient units and in the ED. It certainly would be preferable to require consultants to come in to evaluate patients only when they truly need to be seen while in the hospital.

There also is limited dermatology training in other specialties, and the dermatology team can help fill this gap with educational programs and one-on-one teaching. Hospital teams have signaled this need, but there has been limited success with multiple teaching opportunities.⁴

We believe that this need for inpatient dermatology services can be filled with the newer subspecialty of hospital dermatology, which is not commonly present at most hospitals; a reason why the subspecialty has not been more popular is that there are few available data in the form of randomized clinical trials that can guide inpatient dermatologists with the care of rare hospital skin diseases.⁵ Having a dermatologic hospitalist available might allow for patients to be seen more readily, which ultimately will save lives and health care dollars and would increase real-time teaching and education for house staff, nursing, and attendings at the bedside.

In a 2018 article,⁶ it was postulated that quicker diagnosis of pseudocellulitis and initiation of antibiotics to treat this condition would save the US health care system $210 million annually. We believe that pseudocellulitis would be best evaluated by inpatient dermatology teams, thereby avoiding costly dermatologic consultations, at an average rate of $138.89.⁶

Morbilliform drug eruptions are among the most common skin conditions seen in the hospital; approximately 95% of cases are an uncomplicated reaction to a medication or virus. Data show that many of these consultations might be unnecessary.⁷

Our institution (Hackensack University Medical Center, New Jersey) is a tertiary hospital that also is connected with a major cancer center. Given this connection, skin eruptions due to chemotherapy and radiation are common. The treatment of drug eruptions, graft-vs-host disease, and other oncologic or drug-related eruptions should be within the scope of practice of our hospitalists, but these cases frequently involve dermatologic consultation.

We constructed a consultation flowchart (Figure) to help guide the triage of patients in need of dermatologic evaluation by inpatient teams and possibly to avoid unnecessary consultation fees. The manner in which this—or any flowchart or teaching aid—is conveyed to hospital personnel is critical so that these tools are not perceived as patronizing or confrontational. In our flowchart, we list emergent dermatologic conditions that we believe are appropriate for dermatology consultation including erythrodermic psoriasis, bullous pemphigoid flare, and Stevens-Johnson syndrome/toxic epidermal necrolysis.

We believe that the flowchart can educate inpatient medical teams about appropriate dermatology consultation. Use of the flowchart also may decrease unnecessary consultations, which ultimately will lower health care spending overall.

Edema blisters are a common but often underreported entity most commonly seen on the lower extremities in the setting of acute edema. ¹ Reported risk factors and associations include chronic venous insufficiency, congestive heart failure, hereditary angioedema, and medications (eg, amlodipine). ^1,2 We report a newly described variant that we have termed anasarca-induced desquamation in which a patient sloughed the entire cutaneous surface of the body after gaining almost 40 pounds over 5 days.

Case Report

A 50-year-old man without a home was found minimally responsive in a yard. His core body temperature was 25.5 °C. He was profoundly acidotic (pH, <6.733 [reference range, 7.35–7.45]; lactic acid, 20.5 mmol/L [reference range, 0.5–2.2 mmol/L]) at admission. His medical history was notable for diabetes mellitus, hypertension, alcohol abuse, and pulmonary embolism. The patient was resuscitated with rewarming and intravenous fluids in the setting of acute renal insufficiency. By day 5 of the hospital stay, he had a net positive intake of 21.8 L and an 18-kg (39.7-lb) weight gain.

Dermatology was consulted for skin sloughing. Physical examination revealed nonpainful desquamation of the vermilion lip, periorbital skin, right shoulder, and hips without notable mucosal changes. Two 4-mm punch biopsies of the shoulder revealed an intracorneal split with desquamation of the stratum corneum and a mild dermal lymphocytic infiltrate, consistent with exfoliation secondary to edema or staphylococcal scalded skin syndrome (Figure 1). No staphylococcal growth was noted on blood, urine, nasal, wound, and ocular cultures throughout the hospital stay.

As the patient’s anasarca improved with diuretics and continuous renal replacement therapy, the entire cutaneous surface—head to toe—underwent desquamation, including the palms and soles. He was managed with supportive skin care. The anasarca healed completely with residual hypopigmentation (Figures 2 and 3).

Comment

Anasarca-induced desquamation represents a more diffuse form of a known entity: edema blisters. Occurring most commonly in the setting of acute exacerbation of chronic venous insufficiency, edema blisters can mimic other vesiculobullous conditions, such as bullous pemphigoid and herpes zoster.³

Pathogenesis of Edema Blisters—Edema develops in the skin when the capillary filtration rate, determined by the hydrostatic and oncotic pressures of the capillaries and interstitium, exceeds venous and lymphatic drainage. The appearance of edema blisters in the acute setting likely is related to the speed at which edema develops in skin.¹ Although edema blisters often are described as tense, there is a paucity of histologic data at the anatomical level of split in the skin.In our patient, desquamation was within the stratum corneum and likely multifactorial. His weight gain of nearly 40 lb, the result of intravenous instillation of fluids and low urine output, was undeniably a contributing factor. The anasarca was aggravated by hypoalbuminemia (2.1 g/dL) in the setting of known liver disease. Other possible contributing factors were hypotension, which required vasopressor therapy that led to hypoperfusion of the skin, and treatment of hypothermia, with resulting reactive vasodilation and capillary leak.

Management—Treatment of acute edema blisters is focused on the underlying cause of the edema. In a study of 13 patients with edema blisters, all had blisters on the legs that resolved with treatment, such as diuretics or compression therapy.¹

Anasarca-induced desquamation is an inherently benign condition that mimics potentially fatal disorders, such as Stevens-Johnson syndrome, staphylococcal scalded skin syndrome, and toxic shock syndrome. Therefore, patients presenting with diffuse superficial desquamation should be assessed for the mucosal changes of Stevens-Johnson syndrome and a history of acute edema in the affected areas to avoid potentially harmful empiric treatments, such as corticosteroids and intravenous antibiotics.

Conclusion

Anasarca-induced desquamation represents a more diffuse form of edema blisters. This desquamation can mimic a potentially fatal rash, such as Stevens-Johnson syndrome and staphylococcal scalded skin syndrome.

Edema blisters are a common but often underreported entity most commonly seen on the lower extremities in the setting of acute edema. ¹ Reported risk factors and associations include chronic venous insufficiency, congestive heart failure, hereditary angioedema, and medications (eg, amlodipine). ^1,2 We report a newly described variant that we have termed anasarca-induced desquamation in which a patient sloughed the entire cutaneous surface of the body after gaining almost 40 pounds over 5 days.

Case Report

A 50-year-old man without a home was found minimally responsive in a yard. His core body temperature was 25.5 °C. He was profoundly acidotic (pH, <6.733 [reference range, 7.35–7.45]; lactic acid, 20.5 mmol/L [reference range, 0.5–2.2 mmol/L]) at admission. His medical history was notable for diabetes mellitus, hypertension, alcohol abuse, and pulmonary embolism. The patient was resuscitated with rewarming and intravenous fluids in the setting of acute renal insufficiency. By day 5 of the hospital stay, he had a net positive intake of 21.8 L and an 18-kg (39.7-lb) weight gain.

Dermatology was consulted for skin sloughing. Physical examination revealed nonpainful desquamation of the vermilion lip, periorbital skin, right shoulder, and hips without notable mucosal changes. Two 4-mm punch biopsies of the shoulder revealed an intracorneal split with desquamation of the stratum corneum and a mild dermal lymphocytic infiltrate, consistent with exfoliation secondary to edema or staphylococcal scalded skin syndrome (Figure 1). No staphylococcal growth was noted on blood, urine, nasal, wound, and ocular cultures throughout the hospital stay.

As the patient’s anasarca improved with diuretics and continuous renal replacement therapy, the entire cutaneous surface—head to toe—underwent desquamation, including the palms and soles. He was managed with supportive skin care. The anasarca healed completely with residual hypopigmentation (Figures 2 and 3).

Comment

Anasarca-induced desquamation represents a more diffuse form of a known entity: edema blisters. Occurring most commonly in the setting of acute exacerbation of chronic venous insufficiency, edema blisters can mimic other vesiculobullous conditions, such as bullous pemphigoid and herpes zoster.³

Pathogenesis of Edema Blisters—Edema develops in the skin when the capillary filtration rate, determined by the hydrostatic and oncotic pressures of the capillaries and interstitium, exceeds venous and lymphatic drainage. The appearance of edema blisters in the acute setting likely is related to the speed at which edema develops in skin.¹ Although edema blisters often are described as tense, there is a paucity of histologic data at the anatomical level of split in the skin.In our patient, desquamation was within the stratum corneum and likely multifactorial. His weight gain of nearly 40 lb, the result of intravenous instillation of fluids and low urine output, was undeniably a contributing factor. The anasarca was aggravated by hypoalbuminemia (2.1 g/dL) in the setting of known liver disease. Other possible contributing factors were hypotension, which required vasopressor therapy that led to hypoperfusion of the skin, and treatment of hypothermia, with resulting reactive vasodilation and capillary leak.

Management—Treatment of acute edema blisters is focused on the underlying cause of the edema. In a study of 13 patients with edema blisters, all had blisters on the legs that resolved with treatment, such as diuretics or compression therapy.¹

Anasarca-induced desquamation is an inherently benign condition that mimics potentially fatal disorders, such as Stevens-Johnson syndrome, staphylococcal scalded skin syndrome, and toxic shock syndrome. Therefore, patients presenting with diffuse superficial desquamation should be assessed for the mucosal changes of Stevens-Johnson syndrome and a history of acute edema in the affected areas to avoid potentially harmful empiric treatments, such as corticosteroids and intravenous antibiotics.

Conclusion

Anasarca-induced desquamation represents a more diffuse form of edema blisters. This desquamation can mimic a potentially fatal rash, such as Stevens-Johnson syndrome and staphylococcal scalded skin syndrome.

Edema blisters are a common but often underreported entity most commonly seen on the lower extremities in the setting of acute edema. ¹ Reported risk factors and associations include chronic venous insufficiency, congestive heart failure, hereditary angioedema, and medications (eg, amlodipine). ^1,2 We report a newly described variant that we have termed anasarca-induced desquamation in which a patient sloughed the entire cutaneous surface of the body after gaining almost 40 pounds over 5 days.

Case Report

A 50-year-old man without a home was found minimally responsive in a yard. His core body temperature was 25.5 °C. He was profoundly acidotic (pH, <6.733 [reference range, 7.35–7.45]; lactic acid, 20.5 mmol/L [reference range, 0.5–2.2 mmol/L]) at admission. His medical history was notable for diabetes mellitus, hypertension, alcohol abuse, and pulmonary embolism. The patient was resuscitated with rewarming and intravenous fluids in the setting of acute renal insufficiency. By day 5 of the hospital stay, he had a net positive intake of 21.8 L and an 18-kg (39.7-lb) weight gain.

Dermatology was consulted for skin sloughing. Physical examination revealed nonpainful desquamation of the vermilion lip, periorbital skin, right shoulder, and hips without notable mucosal changes. Two 4-mm punch biopsies of the shoulder revealed an intracorneal split with desquamation of the stratum corneum and a mild dermal lymphocytic infiltrate, consistent with exfoliation secondary to edema or staphylococcal scalded skin syndrome (Figure 1). No staphylococcal growth was noted on blood, urine, nasal, wound, and ocular cultures throughout the hospital stay.

As the patient’s anasarca improved with diuretics and continuous renal replacement therapy, the entire cutaneous surface—head to toe—underwent desquamation, including the palms and soles. He was managed with supportive skin care. The anasarca healed completely with residual hypopigmentation (Figures 2 and 3).

Comment

Anasarca-induced desquamation represents a more diffuse form of a known entity: edema blisters. Occurring most commonly in the setting of acute exacerbation of chronic venous insufficiency, edema blisters can mimic other vesiculobullous conditions, such as bullous pemphigoid and herpes zoster.³

Pathogenesis of Edema Blisters—Edema develops in the skin when the capillary filtration rate, determined by the hydrostatic and oncotic pressures of the capillaries and interstitium, exceeds venous and lymphatic drainage. The appearance of edema blisters in the acute setting likely is related to the speed at which edema develops in skin.¹ Although edema blisters often are described as tense, there is a paucity of histologic data at the anatomical level of split in the skin.In our patient, desquamation was within the stratum corneum and likely multifactorial. His weight gain of nearly 40 lb, the result of intravenous instillation of fluids and low urine output, was undeniably a contributing factor. The anasarca was aggravated by hypoalbuminemia (2.1 g/dL) in the setting of known liver disease. Other possible contributing factors were hypotension, which required vasopressor therapy that led to hypoperfusion of the skin, and treatment of hypothermia, with resulting reactive vasodilation and capillary leak.

Management—Treatment of acute edema blisters is focused on the underlying cause of the edema. In a study of 13 patients with edema blisters, all had blisters on the legs that resolved with treatment, such as diuretics or compression therapy.¹

Anasarca-induced desquamation is an inherently benign condition that mimics potentially fatal disorders, such as Stevens-Johnson syndrome, staphylococcal scalded skin syndrome, and toxic shock syndrome. Therefore, patients presenting with diffuse superficial desquamation should be assessed for the mucosal changes of Stevens-Johnson syndrome and a history of acute edema in the affected areas to avoid potentially harmful empiric treatments, such as corticosteroids and intravenous antibiotics.

Conclusion

Anasarca-induced desquamation represents a more diffuse form of edema blisters. This desquamation can mimic a potentially fatal rash, such as Stevens-Johnson syndrome and staphylococcal scalded skin syndrome.

Case Report

A 58-year-old woman presented to the dermatology office with a widespread pruritic eruption of 3 days’ duration that started in the groin and spread to the rest of the body. No treatments had been attempted. She had no notable medical history, and she denied any recent illness, change in personal care products, or new medications or supplements. She reported a camping trip 2 weeks prior to presentation on the east end of Long Island, New York. She later learned that others on the same trip developed a similar, albeit less widespread, eruption.

Physical examination revealed clear vesicles on the arms, legs, trunk, and pubic area (Figure 1). Dermoscopy revealed a small lone star tick larva in the center of one of the vesicles (Figure 2). The type of tick larva was identified using resources from the Centers for Disease Control and Prevention (Figure 3).¹ Careful inspection revealed dark marks on various vesicles, mostly in the perineum, yielding nearly 20 larvae, which were removed with forceps. The patient was counseled to cover herself in petrolatum for 2 to 3 hours with the hope of smothering any remaining tick larvae. She was given triamcinolone cream and was encouraged to take a nonsedating antihistamine for itch. The patient was seen back in clinic 2 weeks later and the eruption had resolved.

Comment

Spread of Tick-Borne Disease—Ticks and tick-borne disease are increasing major health concerns for humans, domesticated animals, and livestock. Reported cases of bacterial and protozoan tick-borne disease doubled in the United States between 2004 and 2016. Ninety percent of the nearly 60,000 cases of nationally notifiable vector-borne diseases reported in 2017 were linked to ticks.² Geographic ranges of multiple tick species continue to expand, which is thought to be secondary to rising global temperatures, ecologic changes, reforestation, and increases in commerce and travel (Figure 4).³ Not only have warming temperatures contributed to geographic range expansion, they also may extend ticks’ active season. The lone star tick (Amblyomma americanum) is widely distributed throughout much of the eastern United States.⁴ The range of A americanum has expanded north in recent years from its prior core range in the southeastern United States.² One study found that from 2006 to 2016, the vector tick species most commonly collected from humans and submitted to a tick surveillance system in New Jersey shifted from Ixodes scapularis to A americanum.⁵

Bites by Amblyomma Ticks—As with most hard ticks, the life cycle of A americanum lasts 2 years and includes the egg, the 6-legged larva or “seed tick,” the 8-legged immature nymph, and the 8-legged reproductively mature adult (Figure 3). Amblyomma americanum can lay several thousand eggs.² Because our patient had numerous bites, it is plausible that she came into contact with a nest of newly hatched tick larvae. Morphogenesis from larva to nymph, then nymph to adult, requires a blood meal.^6,7 The larvae emerge from eggs deposited on the ground and then crawl up low vegetation where they can easily attach to passing hosts. The tick clings to hair or clothing and waits until the host is at rest before moving to a favorable location and then bites.⁸ When attaching, ticks inject an anesthetic akin to lidocaine, making the bite painless. A tick may spend up to 24 hours on the host prior to biting and then feed for 2 hours to 7 days before releasing.⁹ For the majority of tick-borne illnesses, the tick must remain attached for 24 to 48 hours before disease is transmitted.¹⁰

All stages of Amblyomma, excluding the egg, are capable of transmitting disease.^8,11Amblyomma americanum is called the lone star tick because of the prominent white dot on the back of the adult female. It will feed on small or large mammals during any stage of its life cycle. It is known to transmit Ehrlichia chaffeensis and Ehrlichia ewingii, which cause human ehrlichiosis, and Francisella tularensis, which causes tularemia, Heartland virus, Bourbon virus, and Southern tick-associated rash illness. Delayed anaphylaxis to ingestion of red meat has been attributed to the bite of A americanum. Amblyomma americanum ticks are not known to transmit Lyme disease. The Centers for Disease Control and Prevention does not recommend prophylactic treatment to prevent ehrlichiosis.¹² Tularemia prophylaxis is only recommended in cases of laboratory exposure to infectious materials. Doxycycline prophylaxis is only recommended if the tick is identified as an adult or nymphal I scapularis.¹²

Even when the ticks do not transmit disease, tick bites can cause impressive local reactions. Uncomplicated bites can be painful and leave a puncture wound that can take 1 to 2 weeks to heal.¹³ Rarely, bites can cause a delayed hypersensitivity reaction including fever, pruritus, and urticaria. Granulomas can develop if a tick is improperly removed.⁹ Other reports describe prurigo lesions, skin hemorrhage, papular urticaria, diffuse papules, vesicles and bullae, necrotic ulcers, and patchy alopecia.^14,15 A 2015 systematic controlled study of human bite reactions from A americanum demonstrated the development of itchy erythematous papules and vesicles within 48 hours of larval tick attachment to research participants. The study found tissue damage from A americanum mouthparts, and degranulating mast cells may be evident in as little as 15 minutes.¹⁶ The severity of individual skin reaction is hypothesized to depend on several variables, such as the duration of feeding, size of mouthparts, type of tick secretions, changes in secretions during feeding, and prior exposures of the host.¹⁴

Tick Removal—If patients present to clinic with ticks attached, removal can be challenging. Removal recommendations call for use of blunt forceps or tweezers. Ticks should be grasped near the skin with consistent pressure, and the tick should be pulled straight out, perpendicular to the skin. Twisting motions can cause the head to separate from the body and remain in the bite wound. Immediately following removal, the area should be cleansed with a disinfectant.^10,17 After the tick is removed, some studies recommend storing the tick at −20 °C; should the patient develop disease, the tick could be sent for evaluation.^6,17 If there is no clinical or serologic evidence of infection, testing for the presence of antibodies against tick-borne bacteria at presentation and at 3 and 6 weeks is not recommended due to low sensitivity, low positive predictive value, and cost. Clinicians must only observe and treat if disease occurs.¹⁷

Prevention of Tick Bites—Tick bites are best prevented by avoiding tick-infested areas; when these areas are unavoidable, tick bites may be prevented by wearing long pants with the pant legs tucked into boots. In addition, applying topical DEET (N,N-diethyl-m-toluamide) repellent to exposed skin and treating clothing with permethrin can be helpful.¹⁷ When used alone, DEET provides greater than 90% protection for up to 2.7 hours against A americanum.¹⁸ Permethrin-treated clothing alone is 79% to 100% effective at killing A americanum ticks or disabling them for several hours.¹⁹

Conclusion

Tick-borne illness is an increasingly important cause of human infectious disease. In addition to their role as a disease vector, ticks can produce primary skin disorders. This case posed a diagnostic challenge because of the unusually large number and wide distribution of bites as well as the subsequent vesicular reaction that ensued. It is important to keep tick larvae or adult tick bites in the differential when evaluating a patient to expedite tick removal and begin clinical monitoring. Recognition of A americanum larvae as a potential cause of pruritic papules may be helpful in similar cases. In addition, it is important for dermatologists to be aware of the tick species in their area.

Case Report

A 58-year-old woman presented to the dermatology office with a widespread pruritic eruption of 3 days’ duration that started in the groin and spread to the rest of the body. No treatments had been attempted. She had no notable medical history, and she denied any recent illness, change in personal care products, or new medications or supplements. She reported a camping trip 2 weeks prior to presentation on the east end of Long Island, New York. She later learned that others on the same trip developed a similar, albeit less widespread, eruption.

Physical examination revealed clear vesicles on the arms, legs, trunk, and pubic area (Figure 1). Dermoscopy revealed a small lone star tick larva in the center of one of the vesicles (Figure 2). The type of tick larva was identified using resources from the Centers for Disease Control and Prevention (Figure 3).¹ Careful inspection revealed dark marks on various vesicles, mostly in the perineum, yielding nearly 20 larvae, which were removed with forceps. The patient was counseled to cover herself in petrolatum for 2 to 3 hours with the hope of smothering any remaining tick larvae. She was given triamcinolone cream and was encouraged to take a nonsedating antihistamine for itch. The patient was seen back in clinic 2 weeks later and the eruption had resolved.

Comment

Spread of Tick-Borne Disease—Ticks and tick-borne disease are increasing major health concerns for humans, domesticated animals, and livestock. Reported cases of bacterial and protozoan tick-borne disease doubled in the United States between 2004 and 2016. Ninety percent of the nearly 60,000 cases of nationally notifiable vector-borne diseases reported in 2017 were linked to ticks.² Geographic ranges of multiple tick species continue to expand, which is thought to be secondary to rising global temperatures, ecologic changes, reforestation, and increases in commerce and travel (Figure 4).³ Not only have warming temperatures contributed to geographic range expansion, they also may extend ticks’ active season. The lone star tick (Amblyomma americanum) is widely distributed throughout much of the eastern United States.⁴ The range of A americanum has expanded north in recent years from its prior core range in the southeastern United States.² One study found that from 2006 to 2016, the vector tick species most commonly collected from humans and submitted to a tick surveillance system in New Jersey shifted from Ixodes scapularis to A americanum.⁵

Bites by Amblyomma Ticks—As with most hard ticks, the life cycle of A americanum lasts 2 years and includes the egg, the 6-legged larva or “seed tick,” the 8-legged immature nymph, and the 8-legged reproductively mature adult (Figure 3). Amblyomma americanum can lay several thousand eggs.² Because our patient had numerous bites, it is plausible that she came into contact with a nest of newly hatched tick larvae. Morphogenesis from larva to nymph, then nymph to adult, requires a blood meal.^6,7 The larvae emerge from eggs deposited on the ground and then crawl up low vegetation where they can easily attach to passing hosts. The tick clings to hair or clothing and waits until the host is at rest before moving to a favorable location and then bites.⁸ When attaching, ticks inject an anesthetic akin to lidocaine, making the bite painless. A tick may spend up to 24 hours on the host prior to biting and then feed for 2 hours to 7 days before releasing.⁹ For the majority of tick-borne illnesses, the tick must remain attached for 24 to 48 hours before disease is transmitted.¹⁰

All stages of Amblyomma, excluding the egg, are capable of transmitting disease.^8,11Amblyomma americanum is called the lone star tick because of the prominent white dot on the back of the adult female. It will feed on small or large mammals during any stage of its life cycle. It is known to transmit Ehrlichia chaffeensis and Ehrlichia ewingii, which cause human ehrlichiosis, and Francisella tularensis, which causes tularemia, Heartland virus, Bourbon virus, and Southern tick-associated rash illness. Delayed anaphylaxis to ingestion of red meat has been attributed to the bite of A americanum. Amblyomma americanum ticks are not known to transmit Lyme disease. The Centers for Disease Control and Prevention does not recommend prophylactic treatment to prevent ehrlichiosis.¹² Tularemia prophylaxis is only recommended in cases of laboratory exposure to infectious materials. Doxycycline prophylaxis is only recommended if the tick is identified as an adult or nymphal I scapularis.¹²

Even when the ticks do not transmit disease, tick bites can cause impressive local reactions. Uncomplicated bites can be painful and leave a puncture wound that can take 1 to 2 weeks to heal.¹³ Rarely, bites can cause a delayed hypersensitivity reaction including fever, pruritus, and urticaria. Granulomas can develop if a tick is improperly removed.⁹ Other reports describe prurigo lesions, skin hemorrhage, papular urticaria, diffuse papules, vesicles and bullae, necrotic ulcers, and patchy alopecia.^14,15 A 2015 systematic controlled study of human bite reactions from A americanum demonstrated the development of itchy erythematous papules and vesicles within 48 hours of larval tick attachment to research participants. The study found tissue damage from A americanum mouthparts, and degranulating mast cells may be evident in as little as 15 minutes.¹⁶ The severity of individual skin reaction is hypothesized to depend on several variables, such as the duration of feeding, size of mouthparts, type of tick secretions, changes in secretions during feeding, and prior exposures of the host.¹⁴

Tick Removal—If patients present to clinic with ticks attached, removal can be challenging. Removal recommendations call for use of blunt forceps or tweezers. Ticks should be grasped near the skin with consistent pressure, and the tick should be pulled straight out, perpendicular to the skin. Twisting motions can cause the head to separate from the body and remain in the bite wound. Immediately following removal, the area should be cleansed with a disinfectant.^10,17 After the tick is removed, some studies recommend storing the tick at −20 °C; should the patient develop disease, the tick could be sent for evaluation.^6,17 If there is no clinical or serologic evidence of infection, testing for the presence of antibodies against tick-borne bacteria at presentation and at 3 and 6 weeks is not recommended due to low sensitivity, low positive predictive value, and cost. Clinicians must only observe and treat if disease occurs.¹⁷

Prevention of Tick Bites—Tick bites are best prevented by avoiding tick-infested areas; when these areas are unavoidable, tick bites may be prevented by wearing long pants with the pant legs tucked into boots. In addition, applying topical DEET (N,N-diethyl-m-toluamide) repellent to exposed skin and treating clothing with permethrin can be helpful.¹⁷ When used alone, DEET provides greater than 90% protection for up to 2.7 hours against A americanum.¹⁸ Permethrin-treated clothing alone is 79% to 100% effective at killing A americanum ticks or disabling them for several hours.¹⁹

Conclusion

Tick-borne illness is an increasingly important cause of human infectious disease. In addition to their role as a disease vector, ticks can produce primary skin disorders. This case posed a diagnostic challenge because of the unusually large number and wide distribution of bites as well as the subsequent vesicular reaction that ensued. It is important to keep tick larvae or adult tick bites in the differential when evaluating a patient to expedite tick removal and begin clinical monitoring. Recognition of A americanum larvae as a potential cause of pruritic papules may be helpful in similar cases. In addition, it is important for dermatologists to be aware of the tick species in their area.

Case Report

A 58-year-old woman presented to the dermatology office with a widespread pruritic eruption of 3 days’ duration that started in the groin and spread to the rest of the body. No treatments had been attempted. She had no notable medical history, and she denied any recent illness, change in personal care products, or new medications or supplements. She reported a camping trip 2 weeks prior to presentation on the east end of Long Island, New York. She later learned that others on the same trip developed a similar, albeit less widespread, eruption.

Physical examination revealed clear vesicles on the arms, legs, trunk, and pubic area (Figure 1). Dermoscopy revealed a small lone star tick larva in the center of one of the vesicles (Figure 2). The type of tick larva was identified using resources from the Centers for Disease Control and Prevention (Figure 3).¹ Careful inspection revealed dark marks on various vesicles, mostly in the perineum, yielding nearly 20 larvae, which were removed with forceps. The patient was counseled to cover herself in petrolatum for 2 to 3 hours with the hope of smothering any remaining tick larvae. She was given triamcinolone cream and was encouraged to take a nonsedating antihistamine for itch. The patient was seen back in clinic 2 weeks later and the eruption had resolved.

Comment

Spread of Tick-Borne Disease—Ticks and tick-borne disease are increasing major health concerns for humans, domesticated animals, and livestock. Reported cases of bacterial and protozoan tick-borne disease doubled in the United States between 2004 and 2016. Ninety percent of the nearly 60,000 cases of nationally notifiable vector-borne diseases reported in 2017 were linked to ticks.² Geographic ranges of multiple tick species continue to expand, which is thought to be secondary to rising global temperatures, ecologic changes, reforestation, and increases in commerce and travel (Figure 4).³ Not only have warming temperatures contributed to geographic range expansion, they also may extend ticks’ active season. The lone star tick (Amblyomma americanum) is widely distributed throughout much of the eastern United States.⁴ The range of A americanum has expanded north in recent years from its prior core range in the southeastern United States.² One study found that from 2006 to 2016, the vector tick species most commonly collected from humans and submitted to a tick surveillance system in New Jersey shifted from Ixodes scapularis to A americanum.⁵

Bites by Amblyomma Ticks—As with most hard ticks, the life cycle of A americanum lasts 2 years and includes the egg, the 6-legged larva or “seed tick,” the 8-legged immature nymph, and the 8-legged reproductively mature adult (Figure 3). Amblyomma americanum can lay several thousand eggs.² Because our patient had numerous bites, it is plausible that she came into contact with a nest of newly hatched tick larvae. Morphogenesis from larva to nymph, then nymph to adult, requires a blood meal.^6,7 The larvae emerge from eggs deposited on the ground and then crawl up low vegetation where they can easily attach to passing hosts. The tick clings to hair or clothing and waits until the host is at rest before moving to a favorable location and then bites.⁸ When attaching, ticks inject an anesthetic akin to lidocaine, making the bite painless. A tick may spend up to 24 hours on the host prior to biting and then feed for 2 hours to 7 days before releasing.⁹ For the majority of tick-borne illnesses, the tick must remain attached for 24 to 48 hours before disease is transmitted.¹⁰

All stages of Amblyomma, excluding the egg, are capable of transmitting disease.^8,11Amblyomma americanum is called the lone star tick because of the prominent white dot on the back of the adult female. It will feed on small or large mammals during any stage of its life cycle. It is known to transmit Ehrlichia chaffeensis and Ehrlichia ewingii, which cause human ehrlichiosis, and Francisella tularensis, which causes tularemia, Heartland virus, Bourbon virus, and Southern tick-associated rash illness. Delayed anaphylaxis to ingestion of red meat has been attributed to the bite of A americanum. Amblyomma americanum ticks are not known to transmit Lyme disease. The Centers for Disease Control and Prevention does not recommend prophylactic treatment to prevent ehrlichiosis.¹² Tularemia prophylaxis is only recommended in cases of laboratory exposure to infectious materials. Doxycycline prophylaxis is only recommended if the tick is identified as an adult or nymphal I scapularis.¹²

Even when the ticks do not transmit disease, tick bites can cause impressive local reactions. Uncomplicated bites can be painful and leave a puncture wound that can take 1 to 2 weeks to heal.¹³ Rarely, bites can cause a delayed hypersensitivity reaction including fever, pruritus, and urticaria. Granulomas can develop if a tick is improperly removed.⁹ Other reports describe prurigo lesions, skin hemorrhage, papular urticaria, diffuse papules, vesicles and bullae, necrotic ulcers, and patchy alopecia.^14,15 A 2015 systematic controlled study of human bite reactions from A americanum demonstrated the development of itchy erythematous papules and vesicles within 48 hours of larval tick attachment to research participants. The study found tissue damage from A americanum mouthparts, and degranulating mast cells may be evident in as little as 15 minutes.¹⁶ The severity of individual skin reaction is hypothesized to depend on several variables, such as the duration of feeding, size of mouthparts, type of tick secretions, changes in secretions during feeding, and prior exposures of the host.¹⁴

Tick Removal—If patients present to clinic with ticks attached, removal can be challenging. Removal recommendations call for use of blunt forceps or tweezers. Ticks should be grasped near the skin with consistent pressure, and the tick should be pulled straight out, perpendicular to the skin. Twisting motions can cause the head to separate from the body and remain in the bite wound. Immediately following removal, the area should be cleansed with a disinfectant.^10,17 After the tick is removed, some studies recommend storing the tick at −20 °C; should the patient develop disease, the tick could be sent for evaluation.^6,17 If there is no clinical or serologic evidence of infection, testing for the presence of antibodies against tick-borne bacteria at presentation and at 3 and 6 weeks is not recommended due to low sensitivity, low positive predictive value, and cost. Clinicians must only observe and treat if disease occurs.¹⁷

Prevention of Tick Bites—Tick bites are best prevented by avoiding tick-infested areas; when these areas are unavoidable, tick bites may be prevented by wearing long pants with the pant legs tucked into boots. In addition, applying topical DEET (N,N-diethyl-m-toluamide) repellent to exposed skin and treating clothing with permethrin can be helpful.¹⁷ When used alone, DEET provides greater than 90% protection for up to 2.7 hours against A americanum.¹⁸ Permethrin-treated clothing alone is 79% to 100% effective at killing A americanum ticks or disabling them for several hours.¹⁹

Conclusion

Tick-borne illness is an increasingly important cause of human infectious disease. In addition to their role as a disease vector, ticks can produce primary skin disorders. This case posed a diagnostic challenge because of the unusually large number and wide distribution of bites as well as the subsequent vesicular reaction that ensued. It is important to keep tick larvae or adult tick bites in the differential when evaluating a patient to expedite tick removal and begin clinical monitoring. Recognition of A americanum larvae as a potential cause of pruritic papules may be helpful in similar cases. In addition, it is important for dermatologists to be aware of the tick species in their area.

BOSTON – The American Contact Dermatitis Society (ACDS) has selected aluminum as the Allergen of the Year for 2022. Aluminum salts, which are the major cause of allergic reactions, are “ubiquitous,” Donald Belsito, MD, professor of dermatology at Columbia University, New York, said at the annual meeting of the American Contact Dermatitis Society.

These salts can be found in sunscreen, cosmetics, dental restorations, and food, to name a few, though the most commonly identified reactions are from aluminum hydroxide, which can be found in some vaccines or preparations for allergen-specific immunotherapy. “It’s the aluminum hydroxide that seems to be more allergenic than other aluminum salts,” Dr. Belsito said in an interview.

“It’s not a dangerous allergy; It’s not a threat,” he said, “but it’s something that dermatologists need to be aware of.”

These reactions normally present as itchy nodules that can last for months and even years, like some reactions from patch testing. “We’re not talking about a vaccine allergy in such a way where people are getting anaphylaxis,” JiaDe Yu, MD, a pediatric dermatologist specializing in allergic contact dermatitis at Massachusetts General Hospital, Boston, said in an interview. “An itchy rash is what we tend to see.”

There have also been occasional reports of atopic dermatitis from aluminum in antiperspirants, astringents, as well as from the metallic aluminum.

Dr. Yu noted that aluminum allergies are not thought to be very common, but the overall prevalence is not known. Studies do suggest, however, that the allergy may be more prevalent in children. In one recent study in Sweden, 5% of children and 0.9% of adults who underwent patch testing had an aluminum contact allergy.

Recommendations for testing

Aluminum is not included in baseline patch testing in the United States, though a recent report about the allergen in the journal Dermatitis argued for its inclusion for pediatric patch testing. Both Dr. Belsito and Dr. Yu agreed that the best approach is to do targeted testing. “If there is a suspicion for it, absolutely test for it,” Dr. Yu said, but if a patient comes in with something like eyelid dermatitis or a rash after a hair care appointment, an aluminum allergy is not very likely.

Because aluminum is also present in Finn Chambers for patch testing, Dr. Belsito advised using plastic chambers in people suspected of having an aluminum allergy. He now uses only plastic chambers in children, he said, as some patients have had reactions to the Finn Chambers even if they have no history of reactions to vaccines or other aluminum-containing products.

While aluminum chloride hexahydrate (ACH) 2% in petrolatum is the commercially available preparation in patch testing, a preparation with ACH 10% is more sensitive, Dr. Belsito said. If a physician strongly suspects an aluminum allergy in a patient but the test with the ACH 2% is negative, he or she should then try a 10% solution, he noted, adding that 7-day readings are also necessary to maximize accuracy.

Vaccine safety

One of the concerns about naming aluminum as the allergen of the year is the potential to cause anxiety around vaccines. “We want to make sure that we’re not giving more fuel to people who have an excuse not to get a vaccine,” Dr. Yu said. “We certainly want to reinforce that fact that it is safe.” Dr. Belsito noted that COVID-19 vaccines do not contain aluminum.

Even on the rare chance that a patient does have a reaction to an aluminum-containing vaccine, these subcutaneous nodules resolve over time, Dr. Belsito said. In his own clinical experience, “99.99% of the time they resolve and there is no residual.” He did add that overreacting to the rash by prescribing injectable steroids can lead to steroid atrophy. In these cases, a topical steroid may be more appropriate.

All unexpected or clinically significant vaccine reactions should be reported to the Vaccine Adverse Event Reporting System, cosponsored by the Centers for Disease Control and Prevention and the Food and Drug Administration. The Clinical Immunization Project Safety Assessment Project, from the CDC, also can provide expertise and advice on aluminum-free alternatives for some vaccines.

Dr. Belsito and Dr. Yu have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

BOSTON – The American Contact Dermatitis Society (ACDS) has selected aluminum as the Allergen of the Year for 2022. Aluminum salts, which are the major cause of allergic reactions, are “ubiquitous,” Donald Belsito, MD, professor of dermatology at Columbia University, New York, said at the annual meeting of the American Contact Dermatitis Society.

These salts can be found in sunscreen, cosmetics, dental restorations, and food, to name a few, though the most commonly identified reactions are from aluminum hydroxide, which can be found in some vaccines or preparations for allergen-specific immunotherapy. “It’s the aluminum hydroxide that seems to be more allergenic than other aluminum salts,” Dr. Belsito said in an interview.

“It’s not a dangerous allergy; It’s not a threat,” he said, “but it’s something that dermatologists need to be aware of.”

These reactions normally present as itchy nodules that can last for months and even years, like some reactions from patch testing. “We’re not talking about a vaccine allergy in such a way where people are getting anaphylaxis,” JiaDe Yu, MD, a pediatric dermatologist specializing in allergic contact dermatitis at Massachusetts General Hospital, Boston, said in an interview. “An itchy rash is what we tend to see.”

There have also been occasional reports of atopic dermatitis from aluminum in antiperspirants, astringents, as well as from the metallic aluminum.

Dr. Yu noted that aluminum allergies are not thought to be very common, but the overall prevalence is not known. Studies do suggest, however, that the allergy may be more prevalent in children. In one recent study in Sweden, 5% of children and 0.9% of adults who underwent patch testing had an aluminum contact allergy.

Recommendations for testing

Aluminum is not included in baseline patch testing in the United States, though a recent report about the allergen in the journal Dermatitis argued for its inclusion for pediatric patch testing. Both Dr. Belsito and Dr. Yu agreed that the best approach is to do targeted testing. “If there is a suspicion for it, absolutely test for it,” Dr. Yu said, but if a patient comes in with something like eyelid dermatitis or a rash after a hair care appointment, an aluminum allergy is not very likely.

Because aluminum is also present in Finn Chambers for patch testing, Dr. Belsito advised using plastic chambers in people suspected of having an aluminum allergy. He now uses only plastic chambers in children, he said, as some patients have had reactions to the Finn Chambers even if they have no history of reactions to vaccines or other aluminum-containing products.

While aluminum chloride hexahydrate (ACH) 2% in petrolatum is the commercially available preparation in patch testing, a preparation with ACH 10% is more sensitive, Dr. Belsito said. If a physician strongly suspects an aluminum allergy in a patient but the test with the ACH 2% is negative, he or she should then try a 10% solution, he noted, adding that 7-day readings are also necessary to maximize accuracy.

Vaccine safety

One of the concerns about naming aluminum as the allergen of the year is the potential to cause anxiety around vaccines. “We want to make sure that we’re not giving more fuel to people who have an excuse not to get a vaccine,” Dr. Yu said. “We certainly want to reinforce that fact that it is safe.” Dr. Belsito noted that COVID-19 vaccines do not contain aluminum.

Even on the rare chance that a patient does have a reaction to an aluminum-containing vaccine, these subcutaneous nodules resolve over time, Dr. Belsito said. In his own clinical experience, “99.99% of the time they resolve and there is no residual.” He did add that overreacting to the rash by prescribing injectable steroids can lead to steroid atrophy. In these cases, a topical steroid may be more appropriate.

All unexpected or clinically significant vaccine reactions should be reported to the Vaccine Adverse Event Reporting System, cosponsored by the Centers for Disease Control and Prevention and the Food and Drug Administration. The Clinical Immunization Project Safety Assessment Project, from the CDC, also can provide expertise and advice on aluminum-free alternatives for some vaccines.

Dr. Belsito and Dr. Yu have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

BOSTON – The American Contact Dermatitis Society (ACDS) has selected aluminum as the Allergen of the Year for 2022. Aluminum salts, which are the major cause of allergic reactions, are “ubiquitous,” Donald Belsito, MD, professor of dermatology at Columbia University, New York, said at the annual meeting of the American Contact Dermatitis Society.

These salts can be found in sunscreen, cosmetics, dental restorations, and food, to name a few, though the most commonly identified reactions are from aluminum hydroxide, which can be found in some vaccines or preparations for allergen-specific immunotherapy. “It’s the aluminum hydroxide that seems to be more allergenic than other aluminum salts,” Dr. Belsito said in an interview.

“It’s not a dangerous allergy; It’s not a threat,” he said, “but it’s something that dermatologists need to be aware of.”

These reactions normally present as itchy nodules that can last for months and even years, like some reactions from patch testing. “We’re not talking about a vaccine allergy in such a way where people are getting anaphylaxis,” JiaDe Yu, MD, a pediatric dermatologist specializing in allergic contact dermatitis at Massachusetts General Hospital, Boston, said in an interview. “An itchy rash is what we tend to see.”

There have also been occasional reports of atopic dermatitis from aluminum in antiperspirants, astringents, as well as from the metallic aluminum.

Dr. Yu noted that aluminum allergies are not thought to be very common, but the overall prevalence is not known. Studies do suggest, however, that the allergy may be more prevalent in children. In one recent study in Sweden, 5% of children and 0.9% of adults who underwent patch testing had an aluminum contact allergy.

Recommendations for testing

Aluminum is not included in baseline patch testing in the United States, though a recent report about the allergen in the journal Dermatitis argued for its inclusion for pediatric patch testing. Both Dr. Belsito and Dr. Yu agreed that the best approach is to do targeted testing. “If there is a suspicion for it, absolutely test for it,” Dr. Yu said, but if a patient comes in with something like eyelid dermatitis or a rash after a hair care appointment, an aluminum allergy is not very likely.

Because aluminum is also present in Finn Chambers for patch testing, Dr. Belsito advised using plastic chambers in people suspected of having an aluminum allergy. He now uses only plastic chambers in children, he said, as some patients have had reactions to the Finn Chambers even if they have no history of reactions to vaccines or other aluminum-containing products.

While aluminum chloride hexahydrate (ACH) 2% in petrolatum is the commercially available preparation in patch testing, a preparation with ACH 10% is more sensitive, Dr. Belsito said. If a physician strongly suspects an aluminum allergy in a patient but the test with the ACH 2% is negative, he or she should then try a 10% solution, he noted, adding that 7-day readings are also necessary to maximize accuracy.

Vaccine safety

One of the concerns about naming aluminum as the allergen of the year is the potential to cause anxiety around vaccines. “We want to make sure that we’re not giving more fuel to people who have an excuse not to get a vaccine,” Dr. Yu said. “We certainly want to reinforce that fact that it is safe.” Dr. Belsito noted that COVID-19 vaccines do not contain aluminum.

Even on the rare chance that a patient does have a reaction to an aluminum-containing vaccine, these subcutaneous nodules resolve over time, Dr. Belsito said. In his own clinical experience, “99.99% of the time they resolve and there is no residual.” He did add that overreacting to the rash by prescribing injectable steroids can lead to steroid atrophy. In these cases, a topical steroid may be more appropriate.

All unexpected or clinically significant vaccine reactions should be reported to the Vaccine Adverse Event Reporting System, cosponsored by the Centers for Disease Control and Prevention and the Food and Drug Administration. The Clinical Immunization Project Safety Assessment Project, from the CDC, also can provide expertise and advice on aluminum-free alternatives for some vaccines.

Dr. Belsito and Dr. Yu have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.