Cutis

The Diagnosis: Juvenile Xanthogranuloma

Given the patient’s age, clinical features of the lesion, and characteristic setting-sun pattern on dermoscopy, a diagnosis of juvenile xanthogranuloma (JXG) was made. The patient showed no other signs of neurofibromatosis type 1 (NF1) or systemic disease and was managed conservatively with observation and routine follow-up. Minimal growth of the lesion was noted at 1-year follow-up, and he was meeting all age-appropriate developmental milestones and showed no other symptoms consistent with NF1. 

Juvenile xanthogranuloma is the most common childhood non–Langerhans cell histiocytosis. While it typically manifests as an isolated condition, JXG also can be associated with NF1 as well as juvenile myelomonocytic leukemia.^1-3 Neurofibromatosis type 1 is a multisystem disorder with variable clinical manifestations that commonly is associated with skin findings such as café au lait macules, intertriginous freckling, and neurofibromas, in addition to JXG.^2,3 Diagnosis of JXG should prompt noninvasive evaluation for further signs and symptoms of NF1, including thorough patient and family history and physical examination to identify other characteristic cutaneous findings, and can include consideration of slit lamp eye examination and radiography for identification of osseous findings. 

The pathogenesis of JXG is not fully known, though there is evidence that it may be associated with a mutation in the mitogen-activated protein kinase pathway.¹ The majority of cases appear in the first year of life.⁴ Clinically, JXG can manifest with extracutaneous lesions, including on the eyes and lungs.^5-7 Juvenile xanthogranuloma can be noninvasively diagnosed with dermoscopy. As seen in our patient, dermoscopic findings include a red-yellow or yellow-orange background with an erythematous border, typically described as a setting-sun pattern.^4,8 Biopsy can confirm the diagnosis; however, given the usually benign course, this often is unnecessary. Most pediatric patients with cutaneous manifestations have a self-limited course with regression over several months to years. Generally, no treatment is required for cutaneous manifestations alone; however, lesions can be removed for aesthetic concerns. For those with systemic involvement, a range of other treatments have been used, including chemotherapy, radiotherapy, systemic corticosteroids, and cyclosporine.^6,7 

The differential diagnosis for JXG includes Brooke-Spiegler syndrome, Fabry disease, solitary cutaneous mastocytoma, and tuberous sclerosis complex. Brooke-Spiegler syndrome is an autosomal-dominant condition characterized by the growth of adnexal neoplasms, including trichoepitheliomas, cylindromas, and spiradenomas. These lesions usually manifest on the face but can include other areas such as the trunk.⁹ Fabry disease is an X-linked recessive lysosomal storage disorder with cutaneous manifestations such as angiokeratoma corporis diffusum and hypohidrosis. Patients also may present with systemic symptoms including hypertension and renal and cardiovascular disease.¹⁰ Mastocytosis encompasses several clinical disorders defined by mast cell hyperplasia and accumulation in various organ systems, and solitary cutaneous mastocytoma is the most common manifestation in children.^11,12 Cutaneous mastocytoma can manifest as a single red-brown or yellow papule, usually located on the arms or legs.¹³ Solitary cutaneous mastocytomas in pediatric patients typically are diagnosed based on clinical appearance and the formation of a wheal upon firm palpation (Darier sign).^11-13 Our patient did not demonstrate the Darier sign, and the lesion was asymptomatic. Tuberous sclerosis complex is an autosomal-dominant neurocutaneous disorder with neurologic and skin findings that occur early in the disease course and include facial angiofibromas, hypomelanotic macules, shagreen patches, and café-au-lait macules.¹⁴

The Diagnosis: Juvenile Xanthogranuloma

Given the patient’s age, clinical features of the lesion, and characteristic setting-sun pattern on dermoscopy, a diagnosis of juvenile xanthogranuloma (JXG) was made. The patient showed no other signs of neurofibromatosis type 1 (NF1) or systemic disease and was managed conservatively with observation and routine follow-up. Minimal growth of the lesion was noted at 1-year follow-up, and he was meeting all age-appropriate developmental milestones and showed no other symptoms consistent with NF1. 

Juvenile xanthogranuloma is the most common childhood non–Langerhans cell histiocytosis. While it typically manifests as an isolated condition, JXG also can be associated with NF1 as well as juvenile myelomonocytic leukemia.^1-3 Neurofibromatosis type 1 is a multisystem disorder with variable clinical manifestations that commonly is associated with skin findings such as café au lait macules, intertriginous freckling, and neurofibromas, in addition to JXG.^2,3 Diagnosis of JXG should prompt noninvasive evaluation for further signs and symptoms of NF1, including thorough patient and family history and physical examination to identify other characteristic cutaneous findings, and can include consideration of slit lamp eye examination and radiography for identification of osseous findings. 

The pathogenesis of JXG is not fully known, though there is evidence that it may be associated with a mutation in the mitogen-activated protein kinase pathway.¹ The majority of cases appear in the first year of life.⁴ Clinically, JXG can manifest with extracutaneous lesions, including on the eyes and lungs.^5-7 Juvenile xanthogranuloma can be noninvasively diagnosed with dermoscopy. As seen in our patient, dermoscopic findings include a red-yellow or yellow-orange background with an erythematous border, typically described as a setting-sun pattern.^4,8 Biopsy can confirm the diagnosis; however, given the usually benign course, this often is unnecessary. Most pediatric patients with cutaneous manifestations have a self-limited course with regression over several months to years. Generally, no treatment is required for cutaneous manifestations alone; however, lesions can be removed for aesthetic concerns. For those with systemic involvement, a range of other treatments have been used, including chemotherapy, radiotherapy, systemic corticosteroids, and cyclosporine.^6,7 

The differential diagnosis for JXG includes Brooke-Spiegler syndrome, Fabry disease, solitary cutaneous mastocytoma, and tuberous sclerosis complex. Brooke-Spiegler syndrome is an autosomal-dominant condition characterized by the growth of adnexal neoplasms, including trichoepitheliomas, cylindromas, and spiradenomas. These lesions usually manifest on the face but can include other areas such as the trunk.⁹ Fabry disease is an X-linked recessive lysosomal storage disorder with cutaneous manifestations such as angiokeratoma corporis diffusum and hypohidrosis. Patients also may present with systemic symptoms including hypertension and renal and cardiovascular disease.¹⁰ Mastocytosis encompasses several clinical disorders defined by mast cell hyperplasia and accumulation in various organ systems, and solitary cutaneous mastocytoma is the most common manifestation in children.^11,12 Cutaneous mastocytoma can manifest as a single red-brown or yellow papule, usually located on the arms or legs.¹³ Solitary cutaneous mastocytomas in pediatric patients typically are diagnosed based on clinical appearance and the formation of a wheal upon firm palpation (Darier sign).^11-13 Our patient did not demonstrate the Darier sign, and the lesion was asymptomatic. Tuberous sclerosis complex is an autosomal-dominant neurocutaneous disorder with neurologic and skin findings that occur early in the disease course and include facial angiofibromas, hypomelanotic macules, shagreen patches, and café-au-lait macules.¹⁴

The Diagnosis: Juvenile Xanthogranuloma

Given the patient’s age, clinical features of the lesion, and characteristic setting-sun pattern on dermoscopy, a diagnosis of juvenile xanthogranuloma (JXG) was made. The patient showed no other signs of neurofibromatosis type 1 (NF1) or systemic disease and was managed conservatively with observation and routine follow-up. Minimal growth of the lesion was noted at 1-year follow-up, and he was meeting all age-appropriate developmental milestones and showed no other symptoms consistent with NF1. 

Juvenile xanthogranuloma is the most common childhood non–Langerhans cell histiocytosis. While it typically manifests as an isolated condition, JXG also can be associated with NF1 as well as juvenile myelomonocytic leukemia.^1-3 Neurofibromatosis type 1 is a multisystem disorder with variable clinical manifestations that commonly is associated with skin findings such as café au lait macules, intertriginous freckling, and neurofibromas, in addition to JXG.^2,3 Diagnosis of JXG should prompt noninvasive evaluation for further signs and symptoms of NF1, including thorough patient and family history and physical examination to identify other characteristic cutaneous findings, and can include consideration of slit lamp eye examination and radiography for identification of osseous findings. 

The pathogenesis of JXG is not fully known, though there is evidence that it may be associated with a mutation in the mitogen-activated protein kinase pathway.¹ The majority of cases appear in the first year of life.⁴ Clinically, JXG can manifest with extracutaneous lesions, including on the eyes and lungs.^5-7 Juvenile xanthogranuloma can be noninvasively diagnosed with dermoscopy. As seen in our patient, dermoscopic findings include a red-yellow or yellow-orange background with an erythematous border, typically described as a setting-sun pattern.^4,8 Biopsy can confirm the diagnosis; however, given the usually benign course, this often is unnecessary. Most pediatric patients with cutaneous manifestations have a self-limited course with regression over several months to years. Generally, no treatment is required for cutaneous manifestations alone; however, lesions can be removed for aesthetic concerns. For those with systemic involvement, a range of other treatments have been used, including chemotherapy, radiotherapy, systemic corticosteroids, and cyclosporine.^6,7 

The differential diagnosis for JXG includes Brooke-Spiegler syndrome, Fabry disease, solitary cutaneous mastocytoma, and tuberous sclerosis complex. Brooke-Spiegler syndrome is an autosomal-dominant condition characterized by the growth of adnexal neoplasms, including trichoepitheliomas, cylindromas, and spiradenomas. These lesions usually manifest on the face but can include other areas such as the trunk.⁹ Fabry disease is an X-linked recessive lysosomal storage disorder with cutaneous manifestations such as angiokeratoma corporis diffusum and hypohidrosis. Patients also may present with systemic symptoms including hypertension and renal and cardiovascular disease.¹⁰ Mastocytosis encompasses several clinical disorders defined by mast cell hyperplasia and accumulation in various organ systems, and solitary cutaneous mastocytoma is the most common manifestation in children.^11,12 Cutaneous mastocytoma can manifest as a single red-brown or yellow papule, usually located on the arms or legs.¹³ Solitary cutaneous mastocytomas in pediatric patients typically are diagnosed based on clinical appearance and the formation of a wheal upon firm palpation (Darier sign).^11-13 Our patient did not demonstrate the Darier sign, and the lesion was asymptomatic. Tuberous sclerosis complex is an autosomal-dominant neurocutaneous disorder with neurologic and skin findings that occur early in the disease course and include facial angiofibromas, hypomelanotic macules, shagreen patches, and café-au-lait macules.¹⁴

The patient was diagnosed with erythema ab igne based on characteristic skin findings on physical examination along with a convincing history of chronic localized heat exposure. Erythema ab igne manifests as a persistent reticulated, erythematous, or hyperpigmented rash at sites of chronic heat exposure.¹ Commonplace items that emit heat such as electric heaters, car heaters, heating pads, hot water bottles, and, in our case, laptops also emit infrared radiation, which can lead to changes in the skin with long-term exposure.² Because exposure to these sources often is limited to one area of the body, erythema ab igne usually manifests locally, as exemplified in this case. Chronic heat exposure and infrared radiation from these sources are thought to induce hyperthermia below the threshold for a thermal burn, and the cutaneous findings correspond with the dermal venous plexus.³

Diagnosis of erythema ab igne primarily is made clinically based on characteristic skin findings and exposure history. Relevant history may include occupations with prolonged heat exposure, such as baking, silversmithing, or foundry work. Heat exposure also may result from cultural practices such as cupping with moxibustion.⁴ Additionally, repeated use of heating pads or hot water bottles for pain relief by patients diagnosed with chronic pain or an underlying illness may contribute to development of erythema ab igne.^1,4

Biopsy was not needed for diagnosis of this patient, but if the presentation is equivocal and history of potential exposures is unclear, a biopsy may be taken. A hematoxylin and eosin stain would reveal dilation of small vascular channels in the superficial dermis, contributing to the classic reticulated appearance. Biopsy findings also would reveal either an interface dermatitis or pigment incontinence containing melanin-laden macrophages correlating to either the erythema or hyperpigmentation, respectively.⁴

The prognosis for erythema ab igne is excellent, especially if diagnosed early. Treatment involves removal of the inciting heat source.¹ The discoloration may resolve within a few months to years or may persist. If the hyperpigmentation is persistent, patients may consider laser treatments or lightening agents such as topical hydroquinone or topical tretinoin.⁴ However, if undiagnosed, patients may be at risk for development of a cutaneous malignancy, such as squamous cell carcinoma, Merkel cell carcinoma, poorly differentiated carcinoma, or cutaneous marginal zone lymphoma.^2,4 Malignant transformation has been reported to occur decades after the initial skin eruption, although the risk is rare⁵; however, due to this risk, patients with erythema ab igne should be followed regularly and screened for new lesions in the affected areas.

The patient was diagnosed with erythema ab igne based on characteristic skin findings on physical examination along with a convincing history of chronic localized heat exposure. Erythema ab igne manifests as a persistent reticulated, erythematous, or hyperpigmented rash at sites of chronic heat exposure.¹ Commonplace items that emit heat such as electric heaters, car heaters, heating pads, hot water bottles, and, in our case, laptops also emit infrared radiation, which can lead to changes in the skin with long-term exposure.² Because exposure to these sources often is limited to one area of the body, erythema ab igne usually manifests locally, as exemplified in this case. Chronic heat exposure and infrared radiation from these sources are thought to induce hyperthermia below the threshold for a thermal burn, and the cutaneous findings correspond with the dermal venous plexus.³

Diagnosis of erythema ab igne primarily is made clinically based on characteristic skin findings and exposure history. Relevant history may include occupations with prolonged heat exposure, such as baking, silversmithing, or foundry work. Heat exposure also may result from cultural practices such as cupping with moxibustion.⁴ Additionally, repeated use of heating pads or hot water bottles for pain relief by patients diagnosed with chronic pain or an underlying illness may contribute to development of erythema ab igne.^1,4

Biopsy was not needed for diagnosis of this patient, but if the presentation is equivocal and history of potential exposures is unclear, a biopsy may be taken. A hematoxylin and eosin stain would reveal dilation of small vascular channels in the superficial dermis, contributing to the classic reticulated appearance. Biopsy findings also would reveal either an interface dermatitis or pigment incontinence containing melanin-laden macrophages correlating to either the erythema or hyperpigmentation, respectively.⁴

The prognosis for erythema ab igne is excellent, especially if diagnosed early. Treatment involves removal of the inciting heat source.¹ The discoloration may resolve within a few months to years or may persist. If the hyperpigmentation is persistent, patients may consider laser treatments or lightening agents such as topical hydroquinone or topical tretinoin.⁴ However, if undiagnosed, patients may be at risk for development of a cutaneous malignancy, such as squamous cell carcinoma, Merkel cell carcinoma, poorly differentiated carcinoma, or cutaneous marginal zone lymphoma.^2,4 Malignant transformation has been reported to occur decades after the initial skin eruption, although the risk is rare⁵; however, due to this risk, patients with erythema ab igne should be followed regularly and screened for new lesions in the affected areas.

The patient was diagnosed with erythema ab igne based on characteristic skin findings on physical examination along with a convincing history of chronic localized heat exposure. Erythema ab igne manifests as a persistent reticulated, erythematous, or hyperpigmented rash at sites of chronic heat exposure.¹ Commonplace items that emit heat such as electric heaters, car heaters, heating pads, hot water bottles, and, in our case, laptops also emit infrared radiation, which can lead to changes in the skin with long-term exposure.² Because exposure to these sources often is limited to one area of the body, erythema ab igne usually manifests locally, as exemplified in this case. Chronic heat exposure and infrared radiation from these sources are thought to induce hyperthermia below the threshold for a thermal burn, and the cutaneous findings correspond with the dermal venous plexus.³

Diagnosis of erythema ab igne primarily is made clinically based on characteristic skin findings and exposure history. Relevant history may include occupations with prolonged heat exposure, such as baking, silversmithing, or foundry work. Heat exposure also may result from cultural practices such as cupping with moxibustion.⁴ Additionally, repeated use of heating pads or hot water bottles for pain relief by patients diagnosed with chronic pain or an underlying illness may contribute to development of erythema ab igne.^1,4

Biopsy was not needed for diagnosis of this patient, but if the presentation is equivocal and history of potential exposures is unclear, a biopsy may be taken. A hematoxylin and eosin stain would reveal dilation of small vascular channels in the superficial dermis, contributing to the classic reticulated appearance. Biopsy findings also would reveal either an interface dermatitis or pigment incontinence containing melanin-laden macrophages correlating to either the erythema or hyperpigmentation, respectively.⁴

The prognosis for erythema ab igne is excellent, especially if diagnosed early. Treatment involves removal of the inciting heat source.¹ The discoloration may resolve within a few months to years or may persist. If the hyperpigmentation is persistent, patients may consider laser treatments or lightening agents such as topical hydroquinone or topical tretinoin.⁴ However, if undiagnosed, patients may be at risk for development of a cutaneous malignancy, such as squamous cell carcinoma, Merkel cell carcinoma, poorly differentiated carcinoma, or cutaneous marginal zone lymphoma.^2,4 Malignant transformation has been reported to occur decades after the initial skin eruption, although the risk is rare⁵; however, due to this risk, patients with erythema ab igne should be followed regularly and screened for new lesions in the affected areas.

Are you seeing any increase or trends in cutaneous adverse effects related to the use of GLP-1 agonists in your practice?

DR. SHIELDS: The use of GLP-1 agonists is increasing substantially across numerous populations. Patients are using these medications not only for weight management and diabetes control but also for blood pressure modulation and cardiovascular risk reduction. The market size is expected to grow at a rate of about 6% until 2027. While severe cutaneous adverse effects still are considered relatively rare with GLP-1 agonist use, mild adverse effects are quite common. Dermatologists should be familiar with these effects and how to manage them. Rare but serious cutaneous reactions include morbilliform drug eruptions, dermal hypersensitivity reactions, panniculitis, and bullous pemphigoid. It is thought that some GLP-1 agonists may cause more skin reactions than others; for example, exenatide extended-release has been associated with cutaneous adverse events more frequently than other GLP-1 agonists in a recent comprehensive literature review.

Do you see a role for dermatologists in monitoring or managing the downstream dermatologic effects of GLP-1 agonists over the next few years?

DR. SHIELDS: Absolutely. When patients develop a drug eruption, bullous pemphigoid, or eosinophilic panniculitis, dermatologists are going to be the ones to diagnose and manage therapy. Awareness of these adverse effects is crucial to timely and thoughtful discussions surrounding medication discontinuation vs a “treat through” approach.

Do you recommend coordinating with endocrinologists or obesity medicine specialists when managing shared patients on GLP-1s (particularly if skin concerns arise)?

DR. SHIELDS: Yes. This is crucial to patient success. Co-management can provide clarity around the indication for therapy and allow for a thoughtful risk-benefit discussion with the patient, primary care physician, endocrinologist, cardiologist, etc. In my practice, I have found that many patients do not want to stop therapy even when they develop cutaneous adverse effects. There are options to transition therapy or treat through in some cases, but having a comprehensive monitoring and therapy plan is critical.

Have you encountered cases in which rapid weight loss from GLP-1s worsened conditions such as loose skin, cellulite, or facial lipoatrophy, leading to new aesthetic concerns? How would you recommend counseling and/or treating affected patients?

DR. SHIELDS: Accelerated facial aging is a noticeable adverse effect in patients who undergo treatment with GLP-1 agonists, especially when used off-label for weight loss. Localized loss of facial fat can result in altered facial proportions and excess skin. There are multiple additional mechanisms that may underlie accelerated facial aging in patients on GLP-1s, and really we are just beginning to scratch the surface of why and how this happens. Understanding these mechanisms will open the door to downstream preventive and therapeutic options. If patients experience new aesthetic concerns, I currently work with them to adjust their medication to slow weight loss, recommend improved nutrition and hydration, encourage exercise and weight training to maintain muscle mass, and engage my cosmetic dermatology colleagues to discuss procedures such as dermal fillers.

All patients starting GLP-1 agonists should be thoroughly counseled on risks and adverse effects of their medication. These are well reported and should be considered carefully. Starting with lower medication dosing in conjunction with slow escalation and careful monitoring can be helpful in combatting these adverse effects.

Are you seeing any increase or trends in cutaneous adverse effects related to the use of GLP-1 agonists in your practice?

DR. SHIELDS: The use of GLP-1 agonists is increasing substantially across numerous populations. Patients are using these medications not only for weight management and diabetes control but also for blood pressure modulation and cardiovascular risk reduction. The market size is expected to grow at a rate of about 6% until 2027. While severe cutaneous adverse effects still are considered relatively rare with GLP-1 agonist use, mild adverse effects are quite common. Dermatologists should be familiar with these effects and how to manage them. Rare but serious cutaneous reactions include morbilliform drug eruptions, dermal hypersensitivity reactions, panniculitis, and bullous pemphigoid. It is thought that some GLP-1 agonists may cause more skin reactions than others; for example, exenatide extended-release has been associated with cutaneous adverse events more frequently than other GLP-1 agonists in a recent comprehensive literature review.

Do you see a role for dermatologists in monitoring or managing the downstream dermatologic effects of GLP-1 agonists over the next few years?

DR. SHIELDS: Absolutely. When patients develop a drug eruption, bullous pemphigoid, or eosinophilic panniculitis, dermatologists are going to be the ones to diagnose and manage therapy. Awareness of these adverse effects is crucial to timely and thoughtful discussions surrounding medication discontinuation vs a “treat through” approach.

Do you recommend coordinating with endocrinologists or obesity medicine specialists when managing shared patients on GLP-1s (particularly if skin concerns arise)?

DR. SHIELDS: Yes. This is crucial to patient success. Co-management can provide clarity around the indication for therapy and allow for a thoughtful risk-benefit discussion with the patient, primary care physician, endocrinologist, cardiologist, etc. In my practice, I have found that many patients do not want to stop therapy even when they develop cutaneous adverse effects. There are options to transition therapy or treat through in some cases, but having a comprehensive monitoring and therapy plan is critical.

Have you encountered cases in which rapid weight loss from GLP-1s worsened conditions such as loose skin, cellulite, or facial lipoatrophy, leading to new aesthetic concerns? How would you recommend counseling and/or treating affected patients?

DR. SHIELDS: Accelerated facial aging is a noticeable adverse effect in patients who undergo treatment with GLP-1 agonists, especially when used off-label for weight loss. Localized loss of facial fat can result in altered facial proportions and excess skin. There are multiple additional mechanisms that may underlie accelerated facial aging in patients on GLP-1s, and really we are just beginning to scratch the surface of why and how this happens. Understanding these mechanisms will open the door to downstream preventive and therapeutic options. If patients experience new aesthetic concerns, I currently work with them to adjust their medication to slow weight loss, recommend improved nutrition and hydration, encourage exercise and weight training to maintain muscle mass, and engage my cosmetic dermatology colleagues to discuss procedures such as dermal fillers.

All patients starting GLP-1 agonists should be thoroughly counseled on risks and adverse effects of their medication. These are well reported and should be considered carefully. Starting with lower medication dosing in conjunction with slow escalation and careful monitoring can be helpful in combatting these adverse effects.

Are you seeing any increase or trends in cutaneous adverse effects related to the use of GLP-1 agonists in your practice?

DR. SHIELDS: The use of GLP-1 agonists is increasing substantially across numerous populations. Patients are using these medications not only for weight management and diabetes control but also for blood pressure modulation and cardiovascular risk reduction. The market size is expected to grow at a rate of about 6% until 2027. While severe cutaneous adverse effects still are considered relatively rare with GLP-1 agonist use, mild adverse effects are quite common. Dermatologists should be familiar with these effects and how to manage them. Rare but serious cutaneous reactions include morbilliform drug eruptions, dermal hypersensitivity reactions, panniculitis, and bullous pemphigoid. It is thought that some GLP-1 agonists may cause more skin reactions than others; for example, exenatide extended-release has been associated with cutaneous adverse events more frequently than other GLP-1 agonists in a recent comprehensive literature review.

Do you see a role for dermatologists in monitoring or managing the downstream dermatologic effects of GLP-1 agonists over the next few years?

DR. SHIELDS: Absolutely. When patients develop a drug eruption, bullous pemphigoid, or eosinophilic panniculitis, dermatologists are going to be the ones to diagnose and manage therapy. Awareness of these adverse effects is crucial to timely and thoughtful discussions surrounding medication discontinuation vs a “treat through” approach.

Do you recommend coordinating with endocrinologists or obesity medicine specialists when managing shared patients on GLP-1s (particularly if skin concerns arise)?

DR. SHIELDS: Yes. This is crucial to patient success. Co-management can provide clarity around the indication for therapy and allow for a thoughtful risk-benefit discussion with the patient, primary care physician, endocrinologist, cardiologist, etc. In my practice, I have found that many patients do not want to stop therapy even when they develop cutaneous adverse effects. There are options to transition therapy or treat through in some cases, but having a comprehensive monitoring and therapy plan is critical.

Have you encountered cases in which rapid weight loss from GLP-1s worsened conditions such as loose skin, cellulite, or facial lipoatrophy, leading to new aesthetic concerns? How would you recommend counseling and/or treating affected patients?

DR. SHIELDS: Accelerated facial aging is a noticeable adverse effect in patients who undergo treatment with GLP-1 agonists, especially when used off-label for weight loss. Localized loss of facial fat can result in altered facial proportions and excess skin. There are multiple additional mechanisms that may underlie accelerated facial aging in patients on GLP-1s, and really we are just beginning to scratch the surface of why and how this happens. Understanding these mechanisms will open the door to downstream preventive and therapeutic options. If patients experience new aesthetic concerns, I currently work with them to adjust their medication to slow weight loss, recommend improved nutrition and hydration, encourage exercise and weight training to maintain muscle mass, and engage my cosmetic dermatology colleagues to discuss procedures such as dermal fillers.

All patients starting GLP-1 agonists should be thoroughly counseled on risks and adverse effects of their medication. These are well reported and should be considered carefully. Starting with lower medication dosing in conjunction with slow escalation and careful monitoring can be helpful in combatting these adverse effects.

Use of artificial intelligence (AI) in dermatology has increased over the past decade, likely driven by advances in deep learning algorithms, computing hardware, and machine learning.¹ Studies comparing the performance of AI algorithms to dermatologists in classifying skin disorders have shown conflicting results.^2,3 In this study, we aimed to analyze AI tools used for diagnosing and classifying skin disease and evaluate the role of dermatologists in the creation of AI technology. We also investigated the number of clinical images used in datasets to train AI programs and compared tools that were created with dermatologist input to those created without dermatologist/clinician involvement.

Methods

A search of PubMed articles indexed for MEDLINE using the terms machine learning, artificial intelligence, and dermatology was conducted on September 18, 2022. Articles were included if they described full-length trials; used machine learning for diagnosis of or screening for dermatologic conditions; and used dermoscopic or gross image datasets of the skin, hair, or nails. Articles were categorized into 4 groups based on the conditions covered: chronic wounds, inflammatory skin diseases, mixed conditions, and pigmented skin lesions. Algorithms were sorted into 4 categories: convolutional/convoluted neural network, deep learning model/deep neural network, AI/artificial neural network, and other. Details regarding Fitzpatrick skin type and skin of color (SoC) inclusion in the articles or AI algorithm datasets were recorded. Univariate and multivariate analyses were performed using Microsoft Excel and SAS Studio 3.8. Sensitivity and specificity were calculated for all included AI technology. Sensitivity, specificity, and the number of clinical images were compared among the included articles using analysis of variance and t tests (α=0.05; P<.05 indicated statistical significance).

Results

Our search yielded 1016 articles, 58 of which met the inclusion criteria. Overall, 25.9% (15/58) of the articles utilized AI to diagnose or classify mixed skin diseases; 22.4% (13/58) for pigmented skin lesions; 19.0% (11/58) for wounds; 17.2% (10/58) for inflammatory skin diseases; and 5.2% (3/58) each for acne, psoriasis, and onychomycosis. Overall, 24.0% (14/58) of articles provided information about Fitzpatrick skin type, and 58.7% (34/58) included clinical images depicting SoC. Furthermore, we found that only 20.7% (12/58) of articles on deep learning models included descriptions of patient ethnicity or race in at least 1 dataset, and only 10.3% (6/58) of studies included any information about skin tone in the dataset. Studies with a dermatologist as the last author (most likely to be supervising the project) were more likely to include clinical images depicting SoC than those without (82.6% [19/23] and 16.7% [3/18], respectively [P=.0411]).

The mean (SD) number of clinical images in the study articles was 28,422 (84,050). Thirty-seven (63.8%) of the study articles included gross images, 17 (29.3%) used dermoscopic images, and 4 (6.9%) used both. Twenty-seven (46.6%) articles used convolutional/convoluted neural networks, 15 (25.9%) used deep learning model/deep neural networks, 8 (13.8%) used other algorithms, 6 (10.3%) used AI/artificial neural network, and 2 (3.4%) used fuzzy algorithms. Most studies were conducted in China (29.3% [17/58]), Germany (12.1% [7/58]), India (10.3% [6/58]), multiple nations (10.3% [6/58]), and the United States (10.3% [6/58]). Overall, 82.8% (48/58) of articles included at least 1 dermatologist coauthor. Sensitivity of the AI models was 0.85, and specificity was 0.85. The average percentage of images in the dataset correctly identified by a physician was 76.87% vs 81.62% of images correctly identified by AI. Average agreement between AI and physician assessment was 77.98%, defined as AI and physician both having the same diagnosis. 

Articles authored by dermatologists contained more clinical images than those without dermatologists in key authorship roles (P<.0001)(eTable). Psoriasis-related algorithms had the fewest (mean [SD]: 3173 [4203]), and pigmented skin lesions had the most clinical images (mean [SD]: 53,19l [155,579]).

Comment

Our results indicated that AI studies with dermatologist authors had significantly more images in their datasets (ie, the set of clinical images of skin lesions used to train AI algorithms in diagnosing or classifying lesions) than those with nondermatologist authors (P<.0001)(eTable). Similarly, in a study of AI technology for skin cancer diagnosis, AI studies with dermatologist authors (ie, included in the development of the AI algorithm) had more images than studies without dermatologist authors.¹ Deep learning textbooks have suggested that 5000 clinical images or training input per output category are needed to produce acceptable algorithm performance, and more than 10 million are needed to produce results superior to human performance.^4-10 Despite advances in AI for dermatologic image analysis, the creation of these models often has been directed by nondermatologists¹; therefore, dermatologist involvement in AI development is necessary to facilitate collection of larger image datasets and optimal performance for image diagnosis/classification tasks.

We found that 20.7% of articles on deep learning models included descriptions of patient ethnicity or race, and only 10.3% of studies included any information about skin tone in the dataset. Furthermore, American investigators primarily trained models using clinical images of patients with lighter skin tones, whereas Chinese investigators exclusively included images depicting darker skin tones. Similarly, in a study of 52 cutaneous imaging deep learning articles, only 17.3% (9/52) reported race and/or Fitzpatrick skin type, and only 7.7% (4/52) of articles included both.^2,6,8 Therefore, dermatologists are needed to contribute images representing diverse populations and collaborate in AI research studies, as their involvement is necessary to ensure the accuracy of AI models in classifying lesions or diagnosing skin lesions across all skin types.

Our search was limited to PubMed, and real-world applications could not be evaluated.

Conclusion

In summary, we found that AI studies with dermatologist authors used larger numbers of clinical images in their datasets and more images representing diverse skin types than studies without. Therefore, we advocate for greater involvement of dermatologists in AI research, which might result in better patient outcomes by improving diagnostic accuracy.

Use of artificial intelligence (AI) in dermatology has increased over the past decade, likely driven by advances in deep learning algorithms, computing hardware, and machine learning.¹ Studies comparing the performance of AI algorithms to dermatologists in classifying skin disorders have shown conflicting results.^2,3 In this study, we aimed to analyze AI tools used for diagnosing and classifying skin disease and evaluate the role of dermatologists in the creation of AI technology. We also investigated the number of clinical images used in datasets to train AI programs and compared tools that were created with dermatologist input to those created without dermatologist/clinician involvement.

Methods

A search of PubMed articles indexed for MEDLINE using the terms machine learning, artificial intelligence, and dermatology was conducted on September 18, 2022. Articles were included if they described full-length trials; used machine learning for diagnosis of or screening for dermatologic conditions; and used dermoscopic or gross image datasets of the skin, hair, or nails. Articles were categorized into 4 groups based on the conditions covered: chronic wounds, inflammatory skin diseases, mixed conditions, and pigmented skin lesions. Algorithms were sorted into 4 categories: convolutional/convoluted neural network, deep learning model/deep neural network, AI/artificial neural network, and other. Details regarding Fitzpatrick skin type and skin of color (SoC) inclusion in the articles or AI algorithm datasets were recorded. Univariate and multivariate analyses were performed using Microsoft Excel and SAS Studio 3.8. Sensitivity and specificity were calculated for all included AI technology. Sensitivity, specificity, and the number of clinical images were compared among the included articles using analysis of variance and t tests (α=0.05; P<.05 indicated statistical significance).

Results

Our search yielded 1016 articles, 58 of which met the inclusion criteria. Overall, 25.9% (15/58) of the articles utilized AI to diagnose or classify mixed skin diseases; 22.4% (13/58) for pigmented skin lesions; 19.0% (11/58) for wounds; 17.2% (10/58) for inflammatory skin diseases; and 5.2% (3/58) each for acne, psoriasis, and onychomycosis. Overall, 24.0% (14/58) of articles provided information about Fitzpatrick skin type, and 58.7% (34/58) included clinical images depicting SoC. Furthermore, we found that only 20.7% (12/58) of articles on deep learning models included descriptions of patient ethnicity or race in at least 1 dataset, and only 10.3% (6/58) of studies included any information about skin tone in the dataset. Studies with a dermatologist as the last author (most likely to be supervising the project) were more likely to include clinical images depicting SoC than those without (82.6% [19/23] and 16.7% [3/18], respectively [P=.0411]).

The mean (SD) number of clinical images in the study articles was 28,422 (84,050). Thirty-seven (63.8%) of the study articles included gross images, 17 (29.3%) used dermoscopic images, and 4 (6.9%) used both. Twenty-seven (46.6%) articles used convolutional/convoluted neural networks, 15 (25.9%) used deep learning model/deep neural networks, 8 (13.8%) used other algorithms, 6 (10.3%) used AI/artificial neural network, and 2 (3.4%) used fuzzy algorithms. Most studies were conducted in China (29.3% [17/58]), Germany (12.1% [7/58]), India (10.3% [6/58]), multiple nations (10.3% [6/58]), and the United States (10.3% [6/58]). Overall, 82.8% (48/58) of articles included at least 1 dermatologist coauthor. Sensitivity of the AI models was 0.85, and specificity was 0.85. The average percentage of images in the dataset correctly identified by a physician was 76.87% vs 81.62% of images correctly identified by AI. Average agreement between AI and physician assessment was 77.98%, defined as AI and physician both having the same diagnosis. 

Articles authored by dermatologists contained more clinical images than those without dermatologists in key authorship roles (P<.0001)(eTable). Psoriasis-related algorithms had the fewest (mean [SD]: 3173 [4203]), and pigmented skin lesions had the most clinical images (mean [SD]: 53,19l [155,579]).

Comment

Our results indicated that AI studies with dermatologist authors had significantly more images in their datasets (ie, the set of clinical images of skin lesions used to train AI algorithms in diagnosing or classifying lesions) than those with nondermatologist authors (P<.0001)(eTable). Similarly, in a study of AI technology for skin cancer diagnosis, AI studies with dermatologist authors (ie, included in the development of the AI algorithm) had more images than studies without dermatologist authors.¹ Deep learning textbooks have suggested that 5000 clinical images or training input per output category are needed to produce acceptable algorithm performance, and more than 10 million are needed to produce results superior to human performance.^4-10 Despite advances in AI for dermatologic image analysis, the creation of these models often has been directed by nondermatologists¹; therefore, dermatologist involvement in AI development is necessary to facilitate collection of larger image datasets and optimal performance for image diagnosis/classification tasks.

We found that 20.7% of articles on deep learning models included descriptions of patient ethnicity or race, and only 10.3% of studies included any information about skin tone in the dataset. Furthermore, American investigators primarily trained models using clinical images of patients with lighter skin tones, whereas Chinese investigators exclusively included images depicting darker skin tones. Similarly, in a study of 52 cutaneous imaging deep learning articles, only 17.3% (9/52) reported race and/or Fitzpatrick skin type, and only 7.7% (4/52) of articles included both.^2,6,8 Therefore, dermatologists are needed to contribute images representing diverse populations and collaborate in AI research studies, as their involvement is necessary to ensure the accuracy of AI models in classifying lesions or diagnosing skin lesions across all skin types.

Our search was limited to PubMed, and real-world applications could not be evaluated.

Conclusion

In summary, we found that AI studies with dermatologist authors used larger numbers of clinical images in their datasets and more images representing diverse skin types than studies without. Therefore, we advocate for greater involvement of dermatologists in AI research, which might result in better patient outcomes by improving diagnostic accuracy.

Use of artificial intelligence (AI) in dermatology has increased over the past decade, likely driven by advances in deep learning algorithms, computing hardware, and machine learning.¹ Studies comparing the performance of AI algorithms to dermatologists in classifying skin disorders have shown conflicting results.^2,3 In this study, we aimed to analyze AI tools used for diagnosing and classifying skin disease and evaluate the role of dermatologists in the creation of AI technology. We also investigated the number of clinical images used in datasets to train AI programs and compared tools that were created with dermatologist input to those created without dermatologist/clinician involvement.

Methods

A search of PubMed articles indexed for MEDLINE using the terms machine learning, artificial intelligence, and dermatology was conducted on September 18, 2022. Articles were included if they described full-length trials; used machine learning for diagnosis of or screening for dermatologic conditions; and used dermoscopic or gross image datasets of the skin, hair, or nails. Articles were categorized into 4 groups based on the conditions covered: chronic wounds, inflammatory skin diseases, mixed conditions, and pigmented skin lesions. Algorithms were sorted into 4 categories: convolutional/convoluted neural network, deep learning model/deep neural network, AI/artificial neural network, and other. Details regarding Fitzpatrick skin type and skin of color (SoC) inclusion in the articles or AI algorithm datasets were recorded. Univariate and multivariate analyses were performed using Microsoft Excel and SAS Studio 3.8. Sensitivity and specificity were calculated for all included AI technology. Sensitivity, specificity, and the number of clinical images were compared among the included articles using analysis of variance and t tests (α=0.05; P<.05 indicated statistical significance).

Results

Our search yielded 1016 articles, 58 of which met the inclusion criteria. Overall, 25.9% (15/58) of the articles utilized AI to diagnose or classify mixed skin diseases; 22.4% (13/58) for pigmented skin lesions; 19.0% (11/58) for wounds; 17.2% (10/58) for inflammatory skin diseases; and 5.2% (3/58) each for acne, psoriasis, and onychomycosis. Overall, 24.0% (14/58) of articles provided information about Fitzpatrick skin type, and 58.7% (34/58) included clinical images depicting SoC. Furthermore, we found that only 20.7% (12/58) of articles on deep learning models included descriptions of patient ethnicity or race in at least 1 dataset, and only 10.3% (6/58) of studies included any information about skin tone in the dataset. Studies with a dermatologist as the last author (most likely to be supervising the project) were more likely to include clinical images depicting SoC than those without (82.6% [19/23] and 16.7% [3/18], respectively [P=.0411]).

The mean (SD) number of clinical images in the study articles was 28,422 (84,050). Thirty-seven (63.8%) of the study articles included gross images, 17 (29.3%) used dermoscopic images, and 4 (6.9%) used both. Twenty-seven (46.6%) articles used convolutional/convoluted neural networks, 15 (25.9%) used deep learning model/deep neural networks, 8 (13.8%) used other algorithms, 6 (10.3%) used AI/artificial neural network, and 2 (3.4%) used fuzzy algorithms. Most studies were conducted in China (29.3% [17/58]), Germany (12.1% [7/58]), India (10.3% [6/58]), multiple nations (10.3% [6/58]), and the United States (10.3% [6/58]). Overall, 82.8% (48/58) of articles included at least 1 dermatologist coauthor. Sensitivity of the AI models was 0.85, and specificity was 0.85. The average percentage of images in the dataset correctly identified by a physician was 76.87% vs 81.62% of images correctly identified by AI. Average agreement between AI and physician assessment was 77.98%, defined as AI and physician both having the same diagnosis. 

Articles authored by dermatologists contained more clinical images than those without dermatologists in key authorship roles (P<.0001)(eTable). Psoriasis-related algorithms had the fewest (mean [SD]: 3173 [4203]), and pigmented skin lesions had the most clinical images (mean [SD]: 53,19l [155,579]).

Comment

Our results indicated that AI studies with dermatologist authors had significantly more images in their datasets (ie, the set of clinical images of skin lesions used to train AI algorithms in diagnosing or classifying lesions) than those with nondermatologist authors (P<.0001)(eTable). Similarly, in a study of AI technology for skin cancer diagnosis, AI studies with dermatologist authors (ie, included in the development of the AI algorithm) had more images than studies without dermatologist authors.¹ Deep learning textbooks have suggested that 5000 clinical images or training input per output category are needed to produce acceptable algorithm performance, and more than 10 million are needed to produce results superior to human performance.^4-10 Despite advances in AI for dermatologic image analysis, the creation of these models often has been directed by nondermatologists¹; therefore, dermatologist involvement in AI development is necessary to facilitate collection of larger image datasets and optimal performance for image diagnosis/classification tasks.

We found that 20.7% of articles on deep learning models included descriptions of patient ethnicity or race, and only 10.3% of studies included any information about skin tone in the dataset. Furthermore, American investigators primarily trained models using clinical images of patients with lighter skin tones, whereas Chinese investigators exclusively included images depicting darker skin tones. Similarly, in a study of 52 cutaneous imaging deep learning articles, only 17.3% (9/52) reported race and/or Fitzpatrick skin type, and only 7.7% (4/52) of articles included both.^2,6,8 Therefore, dermatologists are needed to contribute images representing diverse populations and collaborate in AI research studies, as their involvement is necessary to ensure the accuracy of AI models in classifying lesions or diagnosing skin lesions across all skin types.

Our search was limited to PubMed, and real-world applications could not be evaluated.

Conclusion

In summary, we found that AI studies with dermatologist authors used larger numbers of clinical images in their datasets and more images representing diverse skin types than studies without. Therefore, we advocate for greater involvement of dermatologists in AI research, which might result in better patient outcomes by improving diagnostic accuracy.

Nurse practitioners (NPs) and physician assistants (PAs) often help provide dermatologic care but lack the same mandatory specialized postgraduate training required of board-certified dermatologists (BCDs), which includes at least 3 years of dermatology-focused education in an accredited residency program in addition to an intern year of general medicine, pediatrics, or surgery. Dermatology residency is followed by a certification examination administered by the American Board of Dermatology (ABD) or the American Osteopathic Board of Dermatology, leading to board certification. Some physicians choose to do a fellowship, which typically involves an additional 1 to 2 years of postresidency subspeciality training.

Optional postgraduate dermatology training programs for advanced practice providers (APPs) have been offered by some academic institutions and private practice groups since at least 2003, including Lahey Hospital and Medical Center (Burlington, Massachusetts) as well as the University of Rochester Medical Center (Rochester, New York). Despite a lack of accreditation or standardization, the programs can be beneficial for NPs and PAs to expand their dermatologic knowledge and skills and help bridge the care gap within the specialty. Didactics often are conducted in parallel with the educational activities of the parent institution’s traditional dermatology residency program (eg, lectures, grand rounds). While these programs often are managed by practicing dermatology NPs and PAs, dermatologists also may be involved in their education with didactic instruction, curriculum development, and clinical preceptorship. 

In this cross-sectional study, we identified and evaluated 10 postgraduate dermatology training programs for APPs across the United States. With the growing number of NPs and PAs in the dermatology workforce—both in academic and private practice—it is important for BCDs to be aware of the differences in the dermatology training received in order to ensure safe and effective care is provided through supervisory or collaborative roles (depending on state independent practice laws for APPs and to be aware of the implications these programs may have on the field of dermatology.

Methods

To identify postgraduate dermatology training programs for APPs in the United States, we conducted a cross-sectional study using data obtained via a Google search of various combinations of the following terms: nurse practitioner, NP, physician assistant, PA, advance practice provider, APP, dermatology, postgraduate training, residency, and fellowship. We excluded postgraduate dermatology training programs for APPs that required tuition and did not provide a stipend, as well as programs that lacked the formal structure and credibility needed to qualify as legitimate postgraduate training. Many of the excluded programs operate in a manner that raises ethical concerns, offering pay-to-play opportunities under the guise of education. Information collected on each program included the program name, location, parent institution, program length, class size, curriculum, and any associated salary and benefits.

Results

Ten academic and private practice organizations across the United States that offer postgraduate dermatologic training programs for APPs were identified (eTable). Four (40%) programs were advertised as fellowships. Six (60%) of the programs were offered at academic medical centers, and 4 (40%) were offered by private practices. Most programs were located east of the Mississippi River, and many institutions offered instruction at 1 or more locations within the same state (eFigure). The Advanced Dermatology and Cosmetic Surgery private practice group offered training opportunities in multiple states.

Six programs required APPs to become board-certified NPs or PAs prior to enrolling. Most programs enrolled both NPs and PAs, while some only enrolled NPs (eTable). Only 1 (10%) program required NPs to be board certified as a family NP, while another (10%) recommended that applicants have experience in urgent care, emergency medicine, or trauma medicine. Lahey Hospital & Medical Center required experience as an NP in a general setting for 1 to 2 years prior to applying. No program required prior experience in the field of dermatology.

Program length varied from 6 to 24 months, and cohort size typically was limited to 1 to 2 providers (eTable). Although the exact numbers could not be ascertained, most curricula focused on medical dermatology, including clinical and didactic components, but many offered electives such as cosmetic and procedural dermatology. Two institutions (20%) required independent research. Work typically was limited to 40 hours per week, and most paid a full-time employee salary and provided benefits such as health insurance, retirement, and paid leave (eTable). Kansas Medical Clinic (Topeka, Kansas) required at least 3 years of employment in an underserved community following program completion. The Oasis Dermatology private practice group in Texas required a 1-year teaching commitment after program completion. The Advanced Dermatology and Cosmetic Surgery group offered a full-time position upon program completion.

Comment

There is a large difference in the total number of training and credentialing hours when comparing graduate school training and postgraduate credentialing of medical and osteopathic physicians compared with APPs. A new graduate physician has at least twice as many clinical hours as a PA and 10 times as many clinical hours as an NP prior to starting residency. Physicians also typically complete at least 6 times the number of hours of certification examinations compared to NPs and PAs.¹

Nurse practitioner students typically complete the 500 hours of prelicensure clinical training required for NP school in 2 to 4 years.^2,3 The amount of time required for completion is dependent on the degree and experience of the student upon program entry (eg, bachelor of science in nursing vs master of science in nursing as a terminal degree). Physician assistant students are required to complete 2000 prelicensure clinical hours, and most PA programs are 3 years in duration.⁴ Many NP and PA programs require some degree of clinical experience prior to beginning graduate education.⁵

When comparing prelicensure examinations, questions assessing dermatologic knowledge comprise approximately 6% to 10% of the total questions on the United States Medical Licensing Examination Steps 1 and 2.⁶ The Comprehensive Osteopathic Medical Licensing Examination of the United States Level 1 and Level 2-Cognitive Evaluation both have at least 5% of questions dedicated to dermatology.⁷ Approximately 5% of the questions on the Physician Assistant National Certifying Examination are dedicated to dermatology.⁸ The dermatology content on either of the NP certification examinations is unclear.^2,3 In the states of California, Indiana, and New York, national certification through the American Association of Nurse Practitioners or American Nurses Credentialing Center is not required for NPs to practice in their respective states.⁹

Regarding dermatologic board certification, a new graduate NP may obtain certification from the Dermatology Nurse Practitioner Certification Board with 3000 hours of general dermatology practice that may occur during normal working hours.¹⁰ These hours do not have to occur in one of the previously identified postgraduate APP training programs. The National Board of Dermatology Physician Assistants was founded in 2018 and has since dissolved. The National Board of Dermatology Physician Assistants was not accredited and required at least 3 years of training in dermatology with the same dermatologist in addition to completing a 125-question multiple-choice examination.¹¹ Of note, this examination was opposed by both the ABD and the Society for Dermatology Physician Associates.¹² A PA also may become a Diplomate Fellow with the Society of Dermatology Physician Associates after completion of 64.5 hours of online continuing education modules.⁴ Some PAs may choose to obtain a Certificate of Added Qualifications, which is a voluntary credential that helps document specialty experience and expertise in dermatology or other specialties.

In contrast, a dermatology resident physician requires nearly 11,000 to 13,000 hours of clinical training hours, which last 3 to 4 years following medical school.¹³ This training involves direct patient care under supervision in various settings, including hospitals, outpatient clinics, and surgical procedures. In addition to this clinical experience, dermatology residents must pass a 3-step certification examination process administered by the ABD.¹³ This process includes approximately 20 hours of examinations designed to assess both knowledge and practical skills. For those who wish to further specialize, additional fellowship training in areas such as pediatric dermatology, dermatopathology, or Mohs surgery may follow residency; such fellowships involve an extra 2500 to 3500 hours of training and culminate in another certification examination, further refining a resident’s expertise in a specific dermatologic field. Osteopathic physicians may opt out of the ABD 3-step pathway and obtain board certification through the American Osteopathic Board of Dermatology.¹⁴

Many of the programs we evaluated integrate APP trainees into resident education, allowing participation in equivalent didactic curricula, clinical rotations, and departmental academic activities. The salary and benefits associated with these programs are somewhat like those of resident physicians.^15,16 While most tuition-based programs were excluded from our study due to their lack of credibility and alignment with our study criteria, we identified 2 specific programs that stood out as credible despite requiring students to pay tuition. These programs demonstrated a structured and rigorous curriculum with a clear focus on comprehensive dermatologic training, meeting our standards for inclusion. These programs offer dermatologic training for graduates of NP and PA programs at a cost to the student.^15,16 The program at the Florida Atlantic University, Boca Raton, is largely online,¹⁵ and the program at the University of Miami, Florida, offers no direct clinical contact.¹⁶ These programs illustrate the variety of postgraduate dermatology curricula available nationally in comparison to resident salaries; however, they were not included in our formal analysis because they do not provide structured, in-person clinical training consistent with our inclusion criteria. Neither of these programs would enable participants to qualify for credentialing with the Dermatology Nurse Practitioner Certification Board after completion. While this study identified postgraduate training programs for APPs in dermatology advertised online, it is possible some were omitted or not advertised online.

While many of the postgraduate programs we evaluated provide unique educational opportunities for APPs, it is unknown if graduating providers are equipped to handle the care of patients with complex dermatologic needs. Regardless, the increased utilization of APPs by BCDs has been well documented over the past 2 decades.^17-20 It has been suggested that a higher ratio of APPs to dermatologists can decrease the time it takes for a patient to be seen in a clinic.^21-23 However, investigators have expressed concerns that APPs lack standardized surgical training and clinical hour requirements in the field of dermatology.²⁴ Despite these concerns, Medicare claims data show that APPs are performing advanced surgical and cosmetic procedures at increasing rates.^17,18 Other authors have questioned the cost-effectiveness of APPs, as multiple studies have shown that the number of biopsies needed to diagnose 1 case of skin cancer is higher for midlevel providers than for dermatologists.^25-27

Conclusion

With the anticipated expansion of private equity in dermatology and the growth of our Medicare-eligible population, we are likely to see increased utilization of APPs to address the shortage of BCDs.^28,29 Understanding the prelicensure and postlicensure clinical training requirements, examination hours, and extent of dermatology-focused education among APPs and BCDs can help dermatologists collaborate more effectively and ensure safe, high-quality patient care. Standardizing, improving, and providing high-quality education and promoting lifelong learning in the field of dermatology should be celebrated, and dermatologists are the skin experts best equipped to lead dermatologic education forward.

Nurse practitioners (NPs) and physician assistants (PAs) often help provide dermatologic care but lack the same mandatory specialized postgraduate training required of board-certified dermatologists (BCDs), which includes at least 3 years of dermatology-focused education in an accredited residency program in addition to an intern year of general medicine, pediatrics, or surgery. Dermatology residency is followed by a certification examination administered by the American Board of Dermatology (ABD) or the American Osteopathic Board of Dermatology, leading to board certification. Some physicians choose to do a fellowship, which typically involves an additional 1 to 2 years of postresidency subspeciality training.

Optional postgraduate dermatology training programs for advanced practice providers (APPs) have been offered by some academic institutions and private practice groups since at least 2003, including Lahey Hospital and Medical Center (Burlington, Massachusetts) as well as the University of Rochester Medical Center (Rochester, New York). Despite a lack of accreditation or standardization, the programs can be beneficial for NPs and PAs to expand their dermatologic knowledge and skills and help bridge the care gap within the specialty. Didactics often are conducted in parallel with the educational activities of the parent institution’s traditional dermatology residency program (eg, lectures, grand rounds). While these programs often are managed by practicing dermatology NPs and PAs, dermatologists also may be involved in their education with didactic instruction, curriculum development, and clinical preceptorship. 

In this cross-sectional study, we identified and evaluated 10 postgraduate dermatology training programs for APPs across the United States. With the growing number of NPs and PAs in the dermatology workforce—both in academic and private practice—it is important for BCDs to be aware of the differences in the dermatology training received in order to ensure safe and effective care is provided through supervisory or collaborative roles (depending on state independent practice laws for APPs and to be aware of the implications these programs may have on the field of dermatology.

Methods

To identify postgraduate dermatology training programs for APPs in the United States, we conducted a cross-sectional study using data obtained via a Google search of various combinations of the following terms: nurse practitioner, NP, physician assistant, PA, advance practice provider, APP, dermatology, postgraduate training, residency, and fellowship. We excluded postgraduate dermatology training programs for APPs that required tuition and did not provide a stipend, as well as programs that lacked the formal structure and credibility needed to qualify as legitimate postgraduate training. Many of the excluded programs operate in a manner that raises ethical concerns, offering pay-to-play opportunities under the guise of education. Information collected on each program included the program name, location, parent institution, program length, class size, curriculum, and any associated salary and benefits.

Results

Ten academic and private practice organizations across the United States that offer postgraduate dermatologic training programs for APPs were identified (eTable). Four (40%) programs were advertised as fellowships. Six (60%) of the programs were offered at academic medical centers, and 4 (40%) were offered by private practices. Most programs were located east of the Mississippi River, and many institutions offered instruction at 1 or more locations within the same state (eFigure). The Advanced Dermatology and Cosmetic Surgery private practice group offered training opportunities in multiple states.

Six programs required APPs to become board-certified NPs or PAs prior to enrolling. Most programs enrolled both NPs and PAs, while some only enrolled NPs (eTable). Only 1 (10%) program required NPs to be board certified as a family NP, while another (10%) recommended that applicants have experience in urgent care, emergency medicine, or trauma medicine. Lahey Hospital & Medical Center required experience as an NP in a general setting for 1 to 2 years prior to applying. No program required prior experience in the field of dermatology.

Program length varied from 6 to 24 months, and cohort size typically was limited to 1 to 2 providers (eTable). Although the exact numbers could not be ascertained, most curricula focused on medical dermatology, including clinical and didactic components, but many offered electives such as cosmetic and procedural dermatology. Two institutions (20%) required independent research. Work typically was limited to 40 hours per week, and most paid a full-time employee salary and provided benefits such as health insurance, retirement, and paid leave (eTable). Kansas Medical Clinic (Topeka, Kansas) required at least 3 years of employment in an underserved community following program completion. The Oasis Dermatology private practice group in Texas required a 1-year teaching commitment after program completion. The Advanced Dermatology and Cosmetic Surgery group offered a full-time position upon program completion.

Comment

There is a large difference in the total number of training and credentialing hours when comparing graduate school training and postgraduate credentialing of medical and osteopathic physicians compared with APPs. A new graduate physician has at least twice as many clinical hours as a PA and 10 times as many clinical hours as an NP prior to starting residency. Physicians also typically complete at least 6 times the number of hours of certification examinations compared to NPs and PAs.¹

Nurse practitioner students typically complete the 500 hours of prelicensure clinical training required for NP school in 2 to 4 years.^2,3 The amount of time required for completion is dependent on the degree and experience of the student upon program entry (eg, bachelor of science in nursing vs master of science in nursing as a terminal degree). Physician assistant students are required to complete 2000 prelicensure clinical hours, and most PA programs are 3 years in duration.⁴ Many NP and PA programs require some degree of clinical experience prior to beginning graduate education.⁵

When comparing prelicensure examinations, questions assessing dermatologic knowledge comprise approximately 6% to 10% of the total questions on the United States Medical Licensing Examination Steps 1 and 2.⁶ The Comprehensive Osteopathic Medical Licensing Examination of the United States Level 1 and Level 2-Cognitive Evaluation both have at least 5% of questions dedicated to dermatology.⁷ Approximately 5% of the questions on the Physician Assistant National Certifying Examination are dedicated to dermatology.⁸ The dermatology content on either of the NP certification examinations is unclear.^2,3 In the states of California, Indiana, and New York, national certification through the American Association of Nurse Practitioners or American Nurses Credentialing Center is not required for NPs to practice in their respective states.⁹

Regarding dermatologic board certification, a new graduate NP may obtain certification from the Dermatology Nurse Practitioner Certification Board with 3000 hours of general dermatology practice that may occur during normal working hours.¹⁰ These hours do not have to occur in one of the previously identified postgraduate APP training programs. The National Board of Dermatology Physician Assistants was founded in 2018 and has since dissolved. The National Board of Dermatology Physician Assistants was not accredited and required at least 3 years of training in dermatology with the same dermatologist in addition to completing a 125-question multiple-choice examination.¹¹ Of note, this examination was opposed by both the ABD and the Society for Dermatology Physician Associates.¹² A PA also may become a Diplomate Fellow with the Society of Dermatology Physician Associates after completion of 64.5 hours of online continuing education modules.⁴ Some PAs may choose to obtain a Certificate of Added Qualifications, which is a voluntary credential that helps document specialty experience and expertise in dermatology or other specialties.

In contrast, a dermatology resident physician requires nearly 11,000 to 13,000 hours of clinical training hours, which last 3 to 4 years following medical school.¹³ This training involves direct patient care under supervision in various settings, including hospitals, outpatient clinics, and surgical procedures. In addition to this clinical experience, dermatology residents must pass a 3-step certification examination process administered by the ABD.¹³ This process includes approximately 20 hours of examinations designed to assess both knowledge and practical skills. For those who wish to further specialize, additional fellowship training in areas such as pediatric dermatology, dermatopathology, or Mohs surgery may follow residency; such fellowships involve an extra 2500 to 3500 hours of training and culminate in another certification examination, further refining a resident’s expertise in a specific dermatologic field. Osteopathic physicians may opt out of the ABD 3-step pathway and obtain board certification through the American Osteopathic Board of Dermatology.¹⁴

Many of the programs we evaluated integrate APP trainees into resident education, allowing participation in equivalent didactic curricula, clinical rotations, and departmental academic activities. The salary and benefits associated with these programs are somewhat like those of resident physicians.^15,16 While most tuition-based programs were excluded from our study due to their lack of credibility and alignment with our study criteria, we identified 2 specific programs that stood out as credible despite requiring students to pay tuition. These programs demonstrated a structured and rigorous curriculum with a clear focus on comprehensive dermatologic training, meeting our standards for inclusion. These programs offer dermatologic training for graduates of NP and PA programs at a cost to the student.^15,16 The program at the Florida Atlantic University, Boca Raton, is largely online,¹⁵ and the program at the University of Miami, Florida, offers no direct clinical contact.¹⁶ These programs illustrate the variety of postgraduate dermatology curricula available nationally in comparison to resident salaries; however, they were not included in our formal analysis because they do not provide structured, in-person clinical training consistent with our inclusion criteria. Neither of these programs would enable participants to qualify for credentialing with the Dermatology Nurse Practitioner Certification Board after completion. While this study identified postgraduate training programs for APPs in dermatology advertised online, it is possible some were omitted or not advertised online.

While many of the postgraduate programs we evaluated provide unique educational opportunities for APPs, it is unknown if graduating providers are equipped to handle the care of patients with complex dermatologic needs. Regardless, the increased utilization of APPs by BCDs has been well documented over the past 2 decades.^17-20 It has been suggested that a higher ratio of APPs to dermatologists can decrease the time it takes for a patient to be seen in a clinic.^21-23 However, investigators have expressed concerns that APPs lack standardized surgical training and clinical hour requirements in the field of dermatology.²⁴ Despite these concerns, Medicare claims data show that APPs are performing advanced surgical and cosmetic procedures at increasing rates.^17,18 Other authors have questioned the cost-effectiveness of APPs, as multiple studies have shown that the number of biopsies needed to diagnose 1 case of skin cancer is higher for midlevel providers than for dermatologists.^25-27

Conclusion

With the anticipated expansion of private equity in dermatology and the growth of our Medicare-eligible population, we are likely to see increased utilization of APPs to address the shortage of BCDs.^28,29 Understanding the prelicensure and postlicensure clinical training requirements, examination hours, and extent of dermatology-focused education among APPs and BCDs can help dermatologists collaborate more effectively and ensure safe, high-quality patient care. Standardizing, improving, and providing high-quality education and promoting lifelong learning in the field of dermatology should be celebrated, and dermatologists are the skin experts best equipped to lead dermatologic education forward.

Nurse practitioners (NPs) and physician assistants (PAs) often help provide dermatologic care but lack the same mandatory specialized postgraduate training required of board-certified dermatologists (BCDs), which includes at least 3 years of dermatology-focused education in an accredited residency program in addition to an intern year of general medicine, pediatrics, or surgery. Dermatology residency is followed by a certification examination administered by the American Board of Dermatology (ABD) or the American Osteopathic Board of Dermatology, leading to board certification. Some physicians choose to do a fellowship, which typically involves an additional 1 to 2 years of postresidency subspeciality training.

Optional postgraduate dermatology training programs for advanced practice providers (APPs) have been offered by some academic institutions and private practice groups since at least 2003, including Lahey Hospital and Medical Center (Burlington, Massachusetts) as well as the University of Rochester Medical Center (Rochester, New York). Despite a lack of accreditation or standardization, the programs can be beneficial for NPs and PAs to expand their dermatologic knowledge and skills and help bridge the care gap within the specialty. Didactics often are conducted in parallel with the educational activities of the parent institution’s traditional dermatology residency program (eg, lectures, grand rounds). While these programs often are managed by practicing dermatology NPs and PAs, dermatologists also may be involved in their education with didactic instruction, curriculum development, and clinical preceptorship. 

In this cross-sectional study, we identified and evaluated 10 postgraduate dermatology training programs for APPs across the United States. With the growing number of NPs and PAs in the dermatology workforce—both in academic and private practice—it is important for BCDs to be aware of the differences in the dermatology training received in order to ensure safe and effective care is provided through supervisory or collaborative roles (depending on state independent practice laws for APPs and to be aware of the implications these programs may have on the field of dermatology.

Methods

To identify postgraduate dermatology training programs for APPs in the United States, we conducted a cross-sectional study using data obtained via a Google search of various combinations of the following terms: nurse practitioner, NP, physician assistant, PA, advance practice provider, APP, dermatology, postgraduate training, residency, and fellowship. We excluded postgraduate dermatology training programs for APPs that required tuition and did not provide a stipend, as well as programs that lacked the formal structure and credibility needed to qualify as legitimate postgraduate training. Many of the excluded programs operate in a manner that raises ethical concerns, offering pay-to-play opportunities under the guise of education. Information collected on each program included the program name, location, parent institution, program length, class size, curriculum, and any associated salary and benefits.

Results

Ten academic and private practice organizations across the United States that offer postgraduate dermatologic training programs for APPs were identified (eTable). Four (40%) programs were advertised as fellowships. Six (60%) of the programs were offered at academic medical centers, and 4 (40%) were offered by private practices. Most programs were located east of the Mississippi River, and many institutions offered instruction at 1 or more locations within the same state (eFigure). The Advanced Dermatology and Cosmetic Surgery private practice group offered training opportunities in multiple states.

Six programs required APPs to become board-certified NPs or PAs prior to enrolling. Most programs enrolled both NPs and PAs, while some only enrolled NPs (eTable). Only 1 (10%) program required NPs to be board certified as a family NP, while another (10%) recommended that applicants have experience in urgent care, emergency medicine, or trauma medicine. Lahey Hospital & Medical Center required experience as an NP in a general setting for 1 to 2 years prior to applying. No program required prior experience in the field of dermatology.

Program length varied from 6 to 24 months, and cohort size typically was limited to 1 to 2 providers (eTable). Although the exact numbers could not be ascertained, most curricula focused on medical dermatology, including clinical and didactic components, but many offered electives such as cosmetic and procedural dermatology. Two institutions (20%) required independent research. Work typically was limited to 40 hours per week, and most paid a full-time employee salary and provided benefits such as health insurance, retirement, and paid leave (eTable). Kansas Medical Clinic (Topeka, Kansas) required at least 3 years of employment in an underserved community following program completion. The Oasis Dermatology private practice group in Texas required a 1-year teaching commitment after program completion. The Advanced Dermatology and Cosmetic Surgery group offered a full-time position upon program completion.

Comment

There is a large difference in the total number of training and credentialing hours when comparing graduate school training and postgraduate credentialing of medical and osteopathic physicians compared with APPs. A new graduate physician has at least twice as many clinical hours as a PA and 10 times as many clinical hours as an NP prior to starting residency. Physicians also typically complete at least 6 times the number of hours of certification examinations compared to NPs and PAs.¹

Nurse practitioner students typically complete the 500 hours of prelicensure clinical training required for NP school in 2 to 4 years.^2,3 The amount of time required for completion is dependent on the degree and experience of the student upon program entry (eg, bachelor of science in nursing vs master of science in nursing as a terminal degree). Physician assistant students are required to complete 2000 prelicensure clinical hours, and most PA programs are 3 years in duration.⁴ Many NP and PA programs require some degree of clinical experience prior to beginning graduate education.⁵

When comparing prelicensure examinations, questions assessing dermatologic knowledge comprise approximately 6% to 10% of the total questions on the United States Medical Licensing Examination Steps 1 and 2.⁶ The Comprehensive Osteopathic Medical Licensing Examination of the United States Level 1 and Level 2-Cognitive Evaluation both have at least 5% of questions dedicated to dermatology.⁷ Approximately 5% of the questions on the Physician Assistant National Certifying Examination are dedicated to dermatology.⁸ The dermatology content on either of the NP certification examinations is unclear.^2,3 In the states of California, Indiana, and New York, national certification through the American Association of Nurse Practitioners or American Nurses Credentialing Center is not required for NPs to practice in their respective states.⁹

Regarding dermatologic board certification, a new graduate NP may obtain certification from the Dermatology Nurse Practitioner Certification Board with 3000 hours of general dermatology practice that may occur during normal working hours.¹⁰ These hours do not have to occur in one of the previously identified postgraduate APP training programs. The National Board of Dermatology Physician Assistants was founded in 2018 and has since dissolved. The National Board of Dermatology Physician Assistants was not accredited and required at least 3 years of training in dermatology with the same dermatologist in addition to completing a 125-question multiple-choice examination.¹¹ Of note, this examination was opposed by both the ABD and the Society for Dermatology Physician Associates.¹² A PA also may become a Diplomate Fellow with the Society of Dermatology Physician Associates after completion of 64.5 hours of online continuing education modules.⁴ Some PAs may choose to obtain a Certificate of Added Qualifications, which is a voluntary credential that helps document specialty experience and expertise in dermatology or other specialties.

In contrast, a dermatology resident physician requires nearly 11,000 to 13,000 hours of clinical training hours, which last 3 to 4 years following medical school.¹³ This training involves direct patient care under supervision in various settings, including hospitals, outpatient clinics, and surgical procedures. In addition to this clinical experience, dermatology residents must pass a 3-step certification examination process administered by the ABD.¹³ This process includes approximately 20 hours of examinations designed to assess both knowledge and practical skills. For those who wish to further specialize, additional fellowship training in areas such as pediatric dermatology, dermatopathology, or Mohs surgery may follow residency; such fellowships involve an extra 2500 to 3500 hours of training and culminate in another certification examination, further refining a resident’s expertise in a specific dermatologic field. Osteopathic physicians may opt out of the ABD 3-step pathway and obtain board certification through the American Osteopathic Board of Dermatology.¹⁴

Many of the programs we evaluated integrate APP trainees into resident education, allowing participation in equivalent didactic curricula, clinical rotations, and departmental academic activities. The salary and benefits associated with these programs are somewhat like those of resident physicians.^15,16 While most tuition-based programs were excluded from our study due to their lack of credibility and alignment with our study criteria, we identified 2 specific programs that stood out as credible despite requiring students to pay tuition. These programs demonstrated a structured and rigorous curriculum with a clear focus on comprehensive dermatologic training, meeting our standards for inclusion. These programs offer dermatologic training for graduates of NP and PA programs at a cost to the student.^15,16 The program at the Florida Atlantic University, Boca Raton, is largely online,¹⁵ and the program at the University of Miami, Florida, offers no direct clinical contact.¹⁶ These programs illustrate the variety of postgraduate dermatology curricula available nationally in comparison to resident salaries; however, they were not included in our formal analysis because they do not provide structured, in-person clinical training consistent with our inclusion criteria. Neither of these programs would enable participants to qualify for credentialing with the Dermatology Nurse Practitioner Certification Board after completion. While this study identified postgraduate training programs for APPs in dermatology advertised online, it is possible some were omitted or not advertised online.

While many of the postgraduate programs we evaluated provide unique educational opportunities for APPs, it is unknown if graduating providers are equipped to handle the care of patients with complex dermatologic needs. Regardless, the increased utilization of APPs by BCDs has been well documented over the past 2 decades.^17-20 It has been suggested that a higher ratio of APPs to dermatologists can decrease the time it takes for a patient to be seen in a clinic.^21-23 However, investigators have expressed concerns that APPs lack standardized surgical training and clinical hour requirements in the field of dermatology.²⁴ Despite these concerns, Medicare claims data show that APPs are performing advanced surgical and cosmetic procedures at increasing rates.^17,18 Other authors have questioned the cost-effectiveness of APPs, as multiple studies have shown that the number of biopsies needed to diagnose 1 case of skin cancer is higher for midlevel providers than for dermatologists.^25-27

Conclusion

With the anticipated expansion of private equity in dermatology and the growth of our Medicare-eligible population, we are likely to see increased utilization of APPs to address the shortage of BCDs.^28,29 Understanding the prelicensure and postlicensure clinical training requirements, examination hours, and extent of dermatology-focused education among APPs and BCDs can help dermatologists collaborate more effectively and ensure safe, high-quality patient care. Standardizing, improving, and providing high-quality education and promoting lifelong learning in the field of dermatology should be celebrated, and dermatologists are the skin experts best equipped to lead dermatologic education forward.

Practice Gap

Tattoos have become increasingly prevalent in Western culture, with approximately 1 in 4 Americans having at least 1 tattoo. Individuals invest money, time, and even pain in getting tattoos, many of which hold special personal, family, or religious significance.¹ Various cutaneous pathologies may arise in areas of the skin with tattoos, including malignancies and inflammatory reactions to tattoo pigment, and in these cases, surgical management may be indicated.^2,3

Nonmelanoma skin cancers (NMSCs) such as superficial basal cell carcinomas on broadly sun-damaged areas (eg, trunk, torso), squamous cell carcinomas, reactive keratoacanthomas, and reactive pseudoepitheliomatous squamous hyperplasia diagnosed as squamous cell carcinoma have been reported to occur in or near areas of the skin with tattoos.² Mohs micrographic surgery (MMS) is the standard of care for removing NMSCs, particularly when they manifest in cosmetically sensitive areas.⁴ This treatment option allows for careful guided resection of tumors to minimize the risk for recurrence; it also preserves healthy tissue, which typically results in a smaller radial defect after the procedure is complete. 

Chronic reactions to tattoo pigment may include granulomatous tattoo reactions and pseudolymphomas.³ Treatment options may include immunosuppressives such as intralesional triamcinolone as well as pigment destruction via lasers⁵; however, not all tattoos are responsive to these treatments. Surgical excision is an effective and definitive treatment in this context, as tattoo pigment resides in or above the mid dermis to a depth of approximately 400 μm. Intradermal excision effectively removes the antigenic pigment.⁵

In these clinical scenarios, patients may be hesitant to pursue surgical treatment due to concerns that it may alter tattoo appearance. Many clinicians and surgeons may consider definitive treatment and tattoo preservation to be mutually exclusive, but this is not always the case. We propose a technique that utilizes conservative thickness layers (CTL) to minimize disruption to the appearance of tattoos in MMS for treatment of cutaneous malignancies as well as intradermal excision of tattoo pigment in the setting of chronic inflammatory tattoo reactions.

The Technique

In the appropriate clinical context, CTL can effectively result in defects that heal well by secondary intention and minimize collateral tissue distortion.⁴ Lesions manifesting in or near tattooed skin often are responsive to treatment with CTL; furthermore, CTL may preserve some deeper tattoo pigment, resulting in only partial loss of the tattooed skin.

Conservative thickness layers are performed intradermally, similar to removing traditional layers in MMS. For treatment of NMSCs, a margin is scored around the lesion, and then the blade is passed carefully under the lesion nearly parallel to the skin through an intradermal plane. It is important to avoid entering the subcuticular fat (Figure 1). The tissue then is processed normally in the Mohs laboratory for complete circumferential margin evaluation. If necessary and possible, subsequent layers also can be performed in the intradermal plane. Once total circumferential margin control is obtained, the wound is allowed to granulate and heal by secondary intention. As these processes occur, we have found that wound contraction is less likely with the dermis intact, resulting in less impact on the overall appearance of the tattoo (Figures 1 and 2). For very thin lesions, resultant defects may retain some residual tattoo pigment. The residual scars also may be responsive to tattoo revision, although a period of monitoring for recurrence should be considered if there is concern that revising the tattoo could obscure early recurrent tumors. From our experience, utilizing CTL for NMSCs that arise within or near tattoos results in favorable preservation of the tattoo appearance and high patient satisfaction.

The procedure is performed similarly for removal of allergenic tattoo pigment, with careful excision to the mid dermis. Since the areas affected by the cutaneous reaction may be relatively large, surgical precision is required to maintain a uniform depth to remove the tattoo pigment and preserve the deep dermis (Figure 2). Once removed, the defect can be left to granulate and heal by secondary intention. If the patient wants to have the tattoo revised in the future, it would be prudent to utilize pigment that the patient has responded favorably to. In our experience, this approach is effective and yields high patient satisfaction and minimizes morbidity.

Practice Implications

Tattoos often hold special meaning for patients; therefore, treatment of pathologies arising in or near tattooed skin should emphasize maintaining the appearance of the tattoo while still being effective. Conservative thickness layers in MMS and intradermal excisions for allergic reactions to tattoo pigment are an effective treatment strategy that clinicians may consider.

One shortcoming of using CTL for MMS is the need for subsequent layers to clear the tumor; however, data suggest that first-stage cure rates are extremely high even with CTL for appropriately selected patients, with clearance of nearly 80% of tumors on the first stage. Tumors that may be most responsive to CTL include exophytic NMSCs and those arising in areas with a thicker dermis, including the back, legs, and scalp, although other locations including the face, hands, shins, ankles, and feet also may be well suited for CTL.⁴ Another shortcoming of CTL is that skin cancers arising in tattoos may not be considered appropriate for MMS based on the 2012 Appropriate Use Criteria, which consider factors such as location, type of cancer, size of the lesion, and patient characteristics to determine whether a skin cancer is appropriate for treatment with MMS.⁶ When the Appropriate Use Criteria categorizes a cancer as uncertain or inappropriate for MMS, the clinician must use their clinical judgment to determine whether MMS is the preferred treatment approach.⁷ Given the cosmetic significance of tattoos, location of a skin cancer near a tattoo could be taken into account for skin cancers that might otherwise not meet Appropriate Use Criteria. 

Conservative thickness layers in MMS and intradermal excisions of tattoo pigment are both effective techniques of minimizing disruption of tattoos while effectively treating patients.

Practice Gap

Tattoos have become increasingly prevalent in Western culture, with approximately 1 in 4 Americans having at least 1 tattoo. Individuals invest money, time, and even pain in getting tattoos, many of which hold special personal, family, or religious significance.¹ Various cutaneous pathologies may arise in areas of the skin with tattoos, including malignancies and inflammatory reactions to tattoo pigment, and in these cases, surgical management may be indicated.^2,3

Nonmelanoma skin cancers (NMSCs) such as superficial basal cell carcinomas on broadly sun-damaged areas (eg, trunk, torso), squamous cell carcinomas, reactive keratoacanthomas, and reactive pseudoepitheliomatous squamous hyperplasia diagnosed as squamous cell carcinoma have been reported to occur in or near areas of the skin with tattoos.² Mohs micrographic surgery (MMS) is the standard of care for removing NMSCs, particularly when they manifest in cosmetically sensitive areas.⁴ This treatment option allows for careful guided resection of tumors to minimize the risk for recurrence; it also preserves healthy tissue, which typically results in a smaller radial defect after the procedure is complete. 

Chronic reactions to tattoo pigment may include granulomatous tattoo reactions and pseudolymphomas.³ Treatment options may include immunosuppressives such as intralesional triamcinolone as well as pigment destruction via lasers⁵; however, not all tattoos are responsive to these treatments. Surgical excision is an effective and definitive treatment in this context, as tattoo pigment resides in or above the mid dermis to a depth of approximately 400 μm. Intradermal excision effectively removes the antigenic pigment.⁵

In these clinical scenarios, patients may be hesitant to pursue surgical treatment due to concerns that it may alter tattoo appearance. Many clinicians and surgeons may consider definitive treatment and tattoo preservation to be mutually exclusive, but this is not always the case. We propose a technique that utilizes conservative thickness layers (CTL) to minimize disruption to the appearance of tattoos in MMS for treatment of cutaneous malignancies as well as intradermal excision of tattoo pigment in the setting of chronic inflammatory tattoo reactions.

The Technique

In the appropriate clinical context, CTL can effectively result in defects that heal well by secondary intention and minimize collateral tissue distortion.⁴ Lesions manifesting in or near tattooed skin often are responsive to treatment with CTL; furthermore, CTL may preserve some deeper tattoo pigment, resulting in only partial loss of the tattooed skin.

Conservative thickness layers are performed intradermally, similar to removing traditional layers in MMS. For treatment of NMSCs, a margin is scored around the lesion, and then the blade is passed carefully under the lesion nearly parallel to the skin through an intradermal plane. It is important to avoid entering the subcuticular fat (Figure 1). The tissue then is processed normally in the Mohs laboratory for complete circumferential margin evaluation. If necessary and possible, subsequent layers also can be performed in the intradermal plane. Once total circumferential margin control is obtained, the wound is allowed to granulate and heal by secondary intention. As these processes occur, we have found that wound contraction is less likely with the dermis intact, resulting in less impact on the overall appearance of the tattoo (Figures 1 and 2). For very thin lesions, resultant defects may retain some residual tattoo pigment. The residual scars also may be responsive to tattoo revision, although a period of monitoring for recurrence should be considered if there is concern that revising the tattoo could obscure early recurrent tumors. From our experience, utilizing CTL for NMSCs that arise within or near tattoos results in favorable preservation of the tattoo appearance and high patient satisfaction.

The procedure is performed similarly for removal of allergenic tattoo pigment, with careful excision to the mid dermis. Since the areas affected by the cutaneous reaction may be relatively large, surgical precision is required to maintain a uniform depth to remove the tattoo pigment and preserve the deep dermis (Figure 2). Once removed, the defect can be left to granulate and heal by secondary intention. If the patient wants to have the tattoo revised in the future, it would be prudent to utilize pigment that the patient has responded favorably to. In our experience, this approach is effective and yields high patient satisfaction and minimizes morbidity.

Practice Implications

Tattoos often hold special meaning for patients; therefore, treatment of pathologies arising in or near tattooed skin should emphasize maintaining the appearance of the tattoo while still being effective. Conservative thickness layers in MMS and intradermal excisions for allergic reactions to tattoo pigment are an effective treatment strategy that clinicians may consider.

One shortcoming of using CTL for MMS is the need for subsequent layers to clear the tumor; however, data suggest that first-stage cure rates are extremely high even with CTL for appropriately selected patients, with clearance of nearly 80% of tumors on the first stage. Tumors that may be most responsive to CTL include exophytic NMSCs and those arising in areas with a thicker dermis, including the back, legs, and scalp, although other locations including the face, hands, shins, ankles, and feet also may be well suited for CTL.⁴ Another shortcoming of CTL is that skin cancers arising in tattoos may not be considered appropriate for MMS based on the 2012 Appropriate Use Criteria, which consider factors such as location, type of cancer, size of the lesion, and patient characteristics to determine whether a skin cancer is appropriate for treatment with MMS.⁶ When the Appropriate Use Criteria categorizes a cancer as uncertain or inappropriate for MMS, the clinician must use their clinical judgment to determine whether MMS is the preferred treatment approach.⁷ Given the cosmetic significance of tattoos, location of a skin cancer near a tattoo could be taken into account for skin cancers that might otherwise not meet Appropriate Use Criteria. 

Conservative thickness layers in MMS and intradermal excisions of tattoo pigment are both effective techniques of minimizing disruption of tattoos while effectively treating patients.

Practice Gap

Tattoos have become increasingly prevalent in Western culture, with approximately 1 in 4 Americans having at least 1 tattoo. Individuals invest money, time, and even pain in getting tattoos, many of which hold special personal, family, or religious significance.¹ Various cutaneous pathologies may arise in areas of the skin with tattoos, including malignancies and inflammatory reactions to tattoo pigment, and in these cases, surgical management may be indicated.^2,3

Nonmelanoma skin cancers (NMSCs) such as superficial basal cell carcinomas on broadly sun-damaged areas (eg, trunk, torso), squamous cell carcinomas, reactive keratoacanthomas, and reactive pseudoepitheliomatous squamous hyperplasia diagnosed as squamous cell carcinoma have been reported to occur in or near areas of the skin with tattoos.² Mohs micrographic surgery (MMS) is the standard of care for removing NMSCs, particularly when they manifest in cosmetically sensitive areas.⁴ This treatment option allows for careful guided resection of tumors to minimize the risk for recurrence; it also preserves healthy tissue, which typically results in a smaller radial defect after the procedure is complete. 

Chronic reactions to tattoo pigment may include granulomatous tattoo reactions and pseudolymphomas.³ Treatment options may include immunosuppressives such as intralesional triamcinolone as well as pigment destruction via lasers⁵; however, not all tattoos are responsive to these treatments. Surgical excision is an effective and definitive treatment in this context, as tattoo pigment resides in or above the mid dermis to a depth of approximately 400 μm. Intradermal excision effectively removes the antigenic pigment.⁵

In these clinical scenarios, patients may be hesitant to pursue surgical treatment due to concerns that it may alter tattoo appearance. Many clinicians and surgeons may consider definitive treatment and tattoo preservation to be mutually exclusive, but this is not always the case. We propose a technique that utilizes conservative thickness layers (CTL) to minimize disruption to the appearance of tattoos in MMS for treatment of cutaneous malignancies as well as intradermal excision of tattoo pigment in the setting of chronic inflammatory tattoo reactions.

The Technique

In the appropriate clinical context, CTL can effectively result in defects that heal well by secondary intention and minimize collateral tissue distortion.⁴ Lesions manifesting in or near tattooed skin often are responsive to treatment with CTL; furthermore, CTL may preserve some deeper tattoo pigment, resulting in only partial loss of the tattooed skin.

Conservative thickness layers are performed intradermally, similar to removing traditional layers in MMS. For treatment of NMSCs, a margin is scored around the lesion, and then the blade is passed carefully under the lesion nearly parallel to the skin through an intradermal plane. It is important to avoid entering the subcuticular fat (Figure 1). The tissue then is processed normally in the Mohs laboratory for complete circumferential margin evaluation. If necessary and possible, subsequent layers also can be performed in the intradermal plane. Once total circumferential margin control is obtained, the wound is allowed to granulate and heal by secondary intention. As these processes occur, we have found that wound contraction is less likely with the dermis intact, resulting in less impact on the overall appearance of the tattoo (Figures 1 and 2). For very thin lesions, resultant defects may retain some residual tattoo pigment. The residual scars also may be responsive to tattoo revision, although a period of monitoring for recurrence should be considered if there is concern that revising the tattoo could obscure early recurrent tumors. From our experience, utilizing CTL for NMSCs that arise within or near tattoos results in favorable preservation of the tattoo appearance and high patient satisfaction.

The procedure is performed similarly for removal of allergenic tattoo pigment, with careful excision to the mid dermis. Since the areas affected by the cutaneous reaction may be relatively large, surgical precision is required to maintain a uniform depth to remove the tattoo pigment and preserve the deep dermis (Figure 2). Once removed, the defect can be left to granulate and heal by secondary intention. If the patient wants to have the tattoo revised in the future, it would be prudent to utilize pigment that the patient has responded favorably to. In our experience, this approach is effective and yields high patient satisfaction and minimizes morbidity.

Practice Implications

Tattoos often hold special meaning for patients; therefore, treatment of pathologies arising in or near tattooed skin should emphasize maintaining the appearance of the tattoo while still being effective. Conservative thickness layers in MMS and intradermal excisions for allergic reactions to tattoo pigment are an effective treatment strategy that clinicians may consider.

One shortcoming of using CTL for MMS is the need for subsequent layers to clear the tumor; however, data suggest that first-stage cure rates are extremely high even with CTL for appropriately selected patients, with clearance of nearly 80% of tumors on the first stage. Tumors that may be most responsive to CTL include exophytic NMSCs and those arising in areas with a thicker dermis, including the back, legs, and scalp, although other locations including the face, hands, shins, ankles, and feet also may be well suited for CTL.⁴ Another shortcoming of CTL is that skin cancers arising in tattoos may not be considered appropriate for MMS based on the 2012 Appropriate Use Criteria, which consider factors such as location, type of cancer, size of the lesion, and patient characteristics to determine whether a skin cancer is appropriate for treatment with MMS.⁶ When the Appropriate Use Criteria categorizes a cancer as uncertain or inappropriate for MMS, the clinician must use their clinical judgment to determine whether MMS is the preferred treatment approach.⁷ Given the cosmetic significance of tattoos, location of a skin cancer near a tattoo could be taken into account for skin cancers that might otherwise not meet Appropriate Use Criteria. 

Conservative thickness layers in MMS and intradermal excisions of tattoo pigment are both effective techniques of minimizing disruption of tattoos while effectively treating patients.