Cutis

Basal cell carcinoma (BCC) is the most prevalent malignancy in white individuals and its incidence is rapidly increasing. Despite its low mortality rate, BCC can cause severe morbidity and remains a serious health problem with a high economic burden for health care systems. The incidence of BCC is higher in individuals who have red or blonde hair, light eye color, and/or Fitzpatrick skin types I and II. The risk for developing BCC also increases with age, and men are more frequently affected than women.^1,2 Although several factors have been implicated in the etiology of this condition, such as exposure to ionizing radiation, trauma, chemical carcinogenesis, immunosuppression, predisposing syndromes, and host factors (eg, traits that affect susceptibility to disease),^3-5 exposure to UV radiation is considered to be a major risk factor, with most BCCs presenting in sun-exposed areas of the body (eg, face, neck). Prolongate suberythrodermal UV doses, which do not burn the skin but cause erythema in the histological level, can lead to formation of pyrimidine dimers in the dermal and epidermal tissues and cause DNA mutation with potential carcinogenic effects. Due to a large number of outdoor occupations, it is likely that outdoor workers (OWs) with a history of UV exposure may develop BCCs with different features than those seen in indoor workers (IWs). However, there has been debate about the relevance of occupational UV exposure as a risk factor for BCC development.^6,7 The aim of this study was to compare the clinical and histological features of BCCs in OWs versus IWs at a referral hospital in southern Spain.

Methods

Using the electronic pathology records at a referral hospital in southern Spain, we identified medical records between May 1, 2010, and May 1, 2011, of specimens containing the term skin in the specimen box and basal cell carcinoma in the diagnosis box. We excluded patients with a history of or concomitant squamous cell carcinoma. Reexcision of incompletely excised lesions; punch, shave or incisional biopsies; and palliative excisions also were excluded. The specimens were reviewed and classified according to the differentiation pattern of BCC (ie, nodular, superficial, morpheic, micronodular). Basal cell carcinomas with mixed features were classified according to the most predominant subtype.

We also gathered information regarding the patients’ work history (ie, any job held during their lifetime with a minimum duration of 6 months). Patients were asked about the type of work and start/end dates. In patients who performed OW, we evaluated hours per day and months as well as the type of clothing worn (eg, head covering, socks/stockings during work in the summer months).

Each patient was classified as an OW or IW based on his/her stated occupation. The OWs included those who performed all or most of their work (≥6 hours per day for at least 6 months) outdoors in direct sunlight. Most patients in this group included farmers and fishermen. Indoor workers were those who performed most of their work in an indoor environment (eg, shop, factory, office, hospital, library, bank, school, laboratory). Most patients in this group included mechanics and shop assistants. A small group of individuals could not be classified as OWs or IWs and therefore were excluded from the study. Individuals with a history of exposure to ionizing radiation, chemical carcinogenesis, immunosuppression, or predisposing syndromes also were excluded.

We included variables that could be considered independent risk factors for BCC, including age, sex, eye color, natural hair color, Fitzpatrick skin type, history of sunburns, and family history. All data were collected via a personal interview performed by a single dermatologist (H.H-E.) during the follow-up with the patients conducted after obtaining all medical records and contacting eligible patients; none of the patients were lost on follow-up.

The study was approved by the hospital’s ethics committee and written consent was obtained from all recruited patients for analyzing the data acquired and accessing the relevant diagnostic documents (eg, pathology reports).

The cohorts were compared by a χ² test and Student t test, which were performed using the SPSS software version 15. Statistical significance was determined using α=.05, and all tests were 2-sided.

Results

A total of 308 patients were included in the study, comprising 178 (58%) OWs and 130 (42%) IWs. Table 1 summarizes the characteristics of each cohort with the statistical outcomes.

The mean age (SD) of the OWs was significantly higher than the IWs (75.17 [10.74] vs 69.73 [9.98] years; P<.001). The sex distribution among the 2 cohorts was significantly different (P=.002); the OW group featured a slightly higher proportion of men than women (92 [52%] vs 86 [48%]), whereas women were clearly more prevalent in the IW group than men (85 [65%] vs 45 [35%]).

No significant differences regarding eye color (blue/gray vs brown/black) between the 2 cohorts were found (P>.05). In the same way, the 2 cohorts did not show differences in the natural hair color (red/blonde vs brown/black)(P>.05).

Fitzpatrick skin type II was the most common between both cohorts (82 [46%] OWs and 75 [58%] IWs), but no statistical differences regarding the proportions of each skin type were found (P>.05).

History of sunburns (>2 episodes) was significantly different between the 2 cohorts. The incidence of second-degree sunburns in childhood was higher in IWs (P<.00001), while the incidence of second-degree sunburns in adulthood was higher in OWs (P=.002).

Most OWs had a positive family history of BCC (101 [57%]), while the majority of IWs had a negative family history of BCC (90 [69%]). This difference was statistically significant (P=.03).

Table 2 shows the distribution of anatomic sites of BCCs in OWs and IWs. The nose was the most frequently affected area in OWs (35 cases [20%]), while the cheek was the most common location (23 [18%]) in IWs. Comparison of the frequency of BCC incidence for each anatomic location revealed that only the rate for truncal BCC was significantly different; IWs had a higher incidence of truncal BCCs than OWs (P=.0035). Although the differences between groups were not statistically significant, there was a trend toward a higher incidence of BCCs on the forehead in OW (P=.06).

In both cohorts, the most prevalent histologic subtype was nodular BCC (133 [75%] OWs and 88 [68%] IWs), followed by superficial BCC (17 [10%] OWs and 27 [21%] IWs). The incidence rate of nodular BCCs was statistically different between the 2 cohorts, with OWs showing a higher incidence compared to IWs (P=.024). Regarding the superficial subtype, the opposite was observed: IWs had significantly increased risk compared to OWs (P=.05). There was a trend toward a higher incidence of morpheic BCCs in OWs than IWs, but the difference was not statistically significant (P=.07).

Comment

Skin cancer due to occupational UV exposure is more common than is generally recognized,^6,7 but occupational UV exposure as a risk factor for BCC is still an ongoing debate. In this study, we analyzed the different clinical and histological features of BCC in OWs versus IWs.

The geographic area where this study was performed is characterized by a subtropical Mediterranean climate with irregular rainfall; a short, cool to mild winter; and long, dry, hot summers. Summer temperatures usually are hot and regularly exceed 35°C (95°F). UV index (UVI) is a measure of the amount of skin-damaging UV radiation expected to reach the earth’s surface when the sun is highest in the sky (around midday) and ranges from 1 (low risk) to 10 (maximum risk). In southern Spain, the mean UVI is approximately 6 and can reach up to 9 or sometimes 10 in the summer months. Although Fitzpatrick skin types II and III are most common, the elevated UVI indicates that the general population in southern Spain is at a high risk for developing skin cancer.

In our study the mean age of IWs was lower than OWs, which suggests that IWs may develop BCC at a younger age than OWs. This finding is consistent with studies showing that cumulative occupational UV exposure has been associated with development of BCCs in older age groups, while acute intermittent recreational sun exposure, particularly sustained in childhood and adolescence, is linked with BCC in younger patients.⁶

The role of sex as a risk factor for BCC remains unclear. Some reports show that BCC is more common in men than in women.^8-10 In our study, sex distribution was statistically significant (P=.002); there were more women in the IW cohort and more men in the OW cohort. These differences may be explained by cultural and lifestyle patterns, as women who are IWs tend to have office jobs in urban settings and wear modern fashion clothes at work and for recreation. In rural settings, women have agricultural jobs and tend to wear more traditional clothes that offer sun protection.

Positive family history has been suggested to be a constitutional risk factor for BCC development.^8,11,12 In our study, we observed that positive family history was more common in OWs, while most IWs had a negative family history. These differences were significant (P=.03), and OWs had a 2.6-fold increased likelihood of having a positive family history of BCC compared to IWs. Cultural and lifestyle patterns may partially explain this finding. In rural settings, workers tend to have the same job as their parents as a traditional way of life and therefore have similar patterns of UV exposure; in urban settings, individuals may have different jobs than their parents and therefore the pattern of UV exposure may be different. However, a genetic predisposition for developing BCC cannot be excluded. In addition, we have to consider that the information on family history of BCC in the patients was self-reported and not validated, which may limit the results.

The difference in history of second-degree sunburn in childhood was significantly higher in IWs than in OWs (P<.00001). The OW group had a significant rate of sunburns in adulthood (P=.002). The relationship between UV radiation and BCC is complex, and the patterns of sun exposure and their occurrence in different periods of lifetime (ie, childhood vs adulthood) remain controversial.¹³ The overall history of severe sunburns seems to be more important than simply the tendency to burn or tan,^14,15 and a history of sunburns in childhood and adolescence has been associated with early-onset BCC.⁶ Our findings were consistent in that the age of onset of BCCs was lower in IWs who had a history of sunburns in childhood. Basal cell carcinomas developed at older ages in OWs who had a higher incidence of sunburns in adulthood. However, we have to consider that the retrospective nature of the data collection on sunburns in childhood and adulthood was potentially limited, as the information was based on the patients’ memory. Additionally, other non-UV risk factors for BCC, such as ionizing radiation exposure, were not analyzed.

The majority of BCCs developed in sun-exposed areas of the head and neck in both cohorts, and only 35 (20%) and 28 (22%) BCCs were located on the trunk, arms, or legs in OWs and IWs, respectively. In our study, the rate of BCCs on the trunk was significantly lower in OWs than in IWs (P=.0035). Basal cell carcinomas on the trunk have been suggested to be linked to genetic susceptibility^16,17 and reduced DNA repair capacity¹⁸ rather than sun exposure. Our findings support this hypothesis and suggest that occupational sun exposure has no direct relation with truncal BCC. This outcome is consistent with the result of a case-control study conducted by Pelucchi et al¹⁹ (N=1040). The authors concluded that occupational UV exposure was not associated with truncal BCC development but with head/neck BCC, indicating that there may be different etiological mechanisms between truncal and head/neck BCC.¹⁹ In the largest BCC case series published in the literature with 13,457 specimens, the authors stated that tumors on the trunk may represent a particular variant of BCC, in which the theory of chronic versus intermittent UV exposure cannot be simply extrapolated as it is for the rest of BCC sites. Other factors such as genetic predisposition could be involved in the development of truncal BCC.²⁰ Similarly, Ramos et al²¹ suggested that nonmelanoma skin cancers in sun-protected anatomic sites may occur in individuals with impairment in the DNA repair process.

The classification of histological subtypes of BCC helps to predict tumor behavior,²² which can impact the prognosis. In our study, nodular BCC was the most common subtype in both cohorts, followed by superficial BCC. The nodular subtype was increased in OWs compared to IWs, while the superficial subtype was most common in IWs. Bastiaens et al²³ and McCormack et al²⁴ have suggested that the most frequent subtypes of BCC (nodular and superficial) may represent different tumors with distinct causal factors. According to these authors, nodular subtypes are associated with cumulative UV exposure, while superficial subtypes are associated with more intense and intermittent UV exposure. The results of the current study support this hypothesis, as the OW cohort with cumulative UV exposure showed more incidence of nodular BCC than IWs, while the patients with intense and intermittent sun exposure (the IWs) showed more risk of superficial BCC.

The importance of occupational UV exposure in OWs as a risk factor for BCC is still an ongoing discussion. Our data show that occupational UV exposure may be considered an etiological factor for BCC according to histological subtype and anatomic site. Our study is limited by the retrospective nature of the data collection regarding occupation and childhood sunburns, which were based on the patients’ memory and therefore potentially biased. Data regarding family history of BCC also was self-reported and not validated. Another limiting factor was that other non-UV risk factors for BCC, such as ionizing radiation exposure, were not considered. The limited sample size also may have impacted the study results. Among the strengths of the study are the complete response rate, the similar catchment area of OWs and IWs, the common hospital setting of the 2 cohorts, and the similar attention to medical history. All patients were obtained from the practice of a single referral dermatologist and are felt to be representative of our working area. The use of a single dermatologist reduces provider-associated variability.

Conclusion

According to the results of this study, OWs are more likely to develop nodular BCCs with no increased risk for superficial BCCs. The age of onset in OWs is older than in IWs. Some anatomical sites such as the trunk are more commonly affected in IWs. Truncal BCCs may have etiological factors other than UV exposure, such as a genetic predisposition. This study is useful to occupational safety representatives and physicians to stimulate the implementation of prevention strategies for this easily preventable malignancy and may encourage further research.

Basal cell carcinoma (BCC) is the most prevalent malignancy in white individuals and its incidence is rapidly increasing. Despite its low mortality rate, BCC can cause severe morbidity and remains a serious health problem with a high economic burden for health care systems. The incidence of BCC is higher in individuals who have red or blonde hair, light eye color, and/or Fitzpatrick skin types I and II. The risk for developing BCC also increases with age, and men are more frequently affected than women.^1,2 Although several factors have been implicated in the etiology of this condition, such as exposure to ionizing radiation, trauma, chemical carcinogenesis, immunosuppression, predisposing syndromes, and host factors (eg, traits that affect susceptibility to disease),^3-5 exposure to UV radiation is considered to be a major risk factor, with most BCCs presenting in sun-exposed areas of the body (eg, face, neck). Prolongate suberythrodermal UV doses, which do not burn the skin but cause erythema in the histological level, can lead to formation of pyrimidine dimers in the dermal and epidermal tissues and cause DNA mutation with potential carcinogenic effects. Due to a large number of outdoor occupations, it is likely that outdoor workers (OWs) with a history of UV exposure may develop BCCs with different features than those seen in indoor workers (IWs). However, there has been debate about the relevance of occupational UV exposure as a risk factor for BCC development.^6,7 The aim of this study was to compare the clinical and histological features of BCCs in OWs versus IWs at a referral hospital in southern Spain.

Methods

Using the electronic pathology records at a referral hospital in southern Spain, we identified medical records between May 1, 2010, and May 1, 2011, of specimens containing the term skin in the specimen box and basal cell carcinoma in the diagnosis box. We excluded patients with a history of or concomitant squamous cell carcinoma. Reexcision of incompletely excised lesions; punch, shave or incisional biopsies; and palliative excisions also were excluded. The specimens were reviewed and classified according to the differentiation pattern of BCC (ie, nodular, superficial, morpheic, micronodular). Basal cell carcinomas with mixed features were classified according to the most predominant subtype.

We also gathered information regarding the patients’ work history (ie, any job held during their lifetime with a minimum duration of 6 months). Patients were asked about the type of work and start/end dates. In patients who performed OW, we evaluated hours per day and months as well as the type of clothing worn (eg, head covering, socks/stockings during work in the summer months).

Each patient was classified as an OW or IW based on his/her stated occupation. The OWs included those who performed all or most of their work (≥6 hours per day for at least 6 months) outdoors in direct sunlight. Most patients in this group included farmers and fishermen. Indoor workers were those who performed most of their work in an indoor environment (eg, shop, factory, office, hospital, library, bank, school, laboratory). Most patients in this group included mechanics and shop assistants. A small group of individuals could not be classified as OWs or IWs and therefore were excluded from the study. Individuals with a history of exposure to ionizing radiation, chemical carcinogenesis, immunosuppression, or predisposing syndromes also were excluded.

We included variables that could be considered independent risk factors for BCC, including age, sex, eye color, natural hair color, Fitzpatrick skin type, history of sunburns, and family history. All data were collected via a personal interview performed by a single dermatologist (H.H-E.) during the follow-up with the patients conducted after obtaining all medical records and contacting eligible patients; none of the patients were lost on follow-up.

The study was approved by the hospital’s ethics committee and written consent was obtained from all recruited patients for analyzing the data acquired and accessing the relevant diagnostic documents (eg, pathology reports).

The cohorts were compared by a χ² test and Student t test, which were performed using the SPSS software version 15. Statistical significance was determined using α=.05, and all tests were 2-sided.

Results

A total of 308 patients were included in the study, comprising 178 (58%) OWs and 130 (42%) IWs. Table 1 summarizes the characteristics of each cohort with the statistical outcomes.

The mean age (SD) of the OWs was significantly higher than the IWs (75.17 [10.74] vs 69.73 [9.98] years; P<.001). The sex distribution among the 2 cohorts was significantly different (P=.002); the OW group featured a slightly higher proportion of men than women (92 [52%] vs 86 [48%]), whereas women were clearly more prevalent in the IW group than men (85 [65%] vs 45 [35%]).

No significant differences regarding eye color (blue/gray vs brown/black) between the 2 cohorts were found (P>.05). In the same way, the 2 cohorts did not show differences in the natural hair color (red/blonde vs brown/black)(P>.05).

Fitzpatrick skin type II was the most common between both cohorts (82 [46%] OWs and 75 [58%] IWs), but no statistical differences regarding the proportions of each skin type were found (P>.05).

History of sunburns (>2 episodes) was significantly different between the 2 cohorts. The incidence of second-degree sunburns in childhood was higher in IWs (P<.00001), while the incidence of second-degree sunburns in adulthood was higher in OWs (P=.002).

Most OWs had a positive family history of BCC (101 [57%]), while the majority of IWs had a negative family history of BCC (90 [69%]). This difference was statistically significant (P=.03).

Table 2 shows the distribution of anatomic sites of BCCs in OWs and IWs. The nose was the most frequently affected area in OWs (35 cases [20%]), while the cheek was the most common location (23 [18%]) in IWs. Comparison of the frequency of BCC incidence for each anatomic location revealed that only the rate for truncal BCC was significantly different; IWs had a higher incidence of truncal BCCs than OWs (P=.0035). Although the differences between groups were not statistically significant, there was a trend toward a higher incidence of BCCs on the forehead in OW (P=.06).

In both cohorts, the most prevalent histologic subtype was nodular BCC (133 [75%] OWs and 88 [68%] IWs), followed by superficial BCC (17 [10%] OWs and 27 [21%] IWs). The incidence rate of nodular BCCs was statistically different between the 2 cohorts, with OWs showing a higher incidence compared to IWs (P=.024). Regarding the superficial subtype, the opposite was observed: IWs had significantly increased risk compared to OWs (P=.05). There was a trend toward a higher incidence of morpheic BCCs in OWs than IWs, but the difference was not statistically significant (P=.07).

Comment

Skin cancer due to occupational UV exposure is more common than is generally recognized,^6,7 but occupational UV exposure as a risk factor for BCC is still an ongoing debate. In this study, we analyzed the different clinical and histological features of BCC in OWs versus IWs.

The geographic area where this study was performed is characterized by a subtropical Mediterranean climate with irregular rainfall; a short, cool to mild winter; and long, dry, hot summers. Summer temperatures usually are hot and regularly exceed 35°C (95°F). UV index (UVI) is a measure of the amount of skin-damaging UV radiation expected to reach the earth’s surface when the sun is highest in the sky (around midday) and ranges from 1 (low risk) to 10 (maximum risk). In southern Spain, the mean UVI is approximately 6 and can reach up to 9 or sometimes 10 in the summer months. Although Fitzpatrick skin types II and III are most common, the elevated UVI indicates that the general population in southern Spain is at a high risk for developing skin cancer.

In our study the mean age of IWs was lower than OWs, which suggests that IWs may develop BCC at a younger age than OWs. This finding is consistent with studies showing that cumulative occupational UV exposure has been associated with development of BCCs in older age groups, while acute intermittent recreational sun exposure, particularly sustained in childhood and adolescence, is linked with BCC in younger patients.⁶

The role of sex as a risk factor for BCC remains unclear. Some reports show that BCC is more common in men than in women.^8-10 In our study, sex distribution was statistically significant (P=.002); there were more women in the IW cohort and more men in the OW cohort. These differences may be explained by cultural and lifestyle patterns, as women who are IWs tend to have office jobs in urban settings and wear modern fashion clothes at work and for recreation. In rural settings, women have agricultural jobs and tend to wear more traditional clothes that offer sun protection.

Positive family history has been suggested to be a constitutional risk factor for BCC development.^8,11,12 In our study, we observed that positive family history was more common in OWs, while most IWs had a negative family history. These differences were significant (P=.03), and OWs had a 2.6-fold increased likelihood of having a positive family history of BCC compared to IWs. Cultural and lifestyle patterns may partially explain this finding. In rural settings, workers tend to have the same job as their parents as a traditional way of life and therefore have similar patterns of UV exposure; in urban settings, individuals may have different jobs than their parents and therefore the pattern of UV exposure may be different. However, a genetic predisposition for developing BCC cannot be excluded. In addition, we have to consider that the information on family history of BCC in the patients was self-reported and not validated, which may limit the results.

The difference in history of second-degree sunburn in childhood was significantly higher in IWs than in OWs (P<.00001). The OW group had a significant rate of sunburns in adulthood (P=.002). The relationship between UV radiation and BCC is complex, and the patterns of sun exposure and their occurrence in different periods of lifetime (ie, childhood vs adulthood) remain controversial.¹³ The overall history of severe sunburns seems to be more important than simply the tendency to burn or tan,^14,15 and a history of sunburns in childhood and adolescence has been associated with early-onset BCC.⁶ Our findings were consistent in that the age of onset of BCCs was lower in IWs who had a history of sunburns in childhood. Basal cell carcinomas developed at older ages in OWs who had a higher incidence of sunburns in adulthood. However, we have to consider that the retrospective nature of the data collection on sunburns in childhood and adulthood was potentially limited, as the information was based on the patients’ memory. Additionally, other non-UV risk factors for BCC, such as ionizing radiation exposure, were not analyzed.

The majority of BCCs developed in sun-exposed areas of the head and neck in both cohorts, and only 35 (20%) and 28 (22%) BCCs were located on the trunk, arms, or legs in OWs and IWs, respectively. In our study, the rate of BCCs on the trunk was significantly lower in OWs than in IWs (P=.0035). Basal cell carcinomas on the trunk have been suggested to be linked to genetic susceptibility^16,17 and reduced DNA repair capacity¹⁸ rather than sun exposure. Our findings support this hypothesis and suggest that occupational sun exposure has no direct relation with truncal BCC. This outcome is consistent with the result of a case-control study conducted by Pelucchi et al¹⁹ (N=1040). The authors concluded that occupational UV exposure was not associated with truncal BCC development but with head/neck BCC, indicating that there may be different etiological mechanisms between truncal and head/neck BCC.¹⁹ In the largest BCC case series published in the literature with 13,457 specimens, the authors stated that tumors on the trunk may represent a particular variant of BCC, in which the theory of chronic versus intermittent UV exposure cannot be simply extrapolated as it is for the rest of BCC sites. Other factors such as genetic predisposition could be involved in the development of truncal BCC.²⁰ Similarly, Ramos et al²¹ suggested that nonmelanoma skin cancers in sun-protected anatomic sites may occur in individuals with impairment in the DNA repair process.

The classification of histological subtypes of BCC helps to predict tumor behavior,²² which can impact the prognosis. In our study, nodular BCC was the most common subtype in both cohorts, followed by superficial BCC. The nodular subtype was increased in OWs compared to IWs, while the superficial subtype was most common in IWs. Bastiaens et al²³ and McCormack et al²⁴ have suggested that the most frequent subtypes of BCC (nodular and superficial) may represent different tumors with distinct causal factors. According to these authors, nodular subtypes are associated with cumulative UV exposure, while superficial subtypes are associated with more intense and intermittent UV exposure. The results of the current study support this hypothesis, as the OW cohort with cumulative UV exposure showed more incidence of nodular BCC than IWs, while the patients with intense and intermittent sun exposure (the IWs) showed more risk of superficial BCC.

The importance of occupational UV exposure in OWs as a risk factor for BCC is still an ongoing discussion. Our data show that occupational UV exposure may be considered an etiological factor for BCC according to histological subtype and anatomic site. Our study is limited by the retrospective nature of the data collection regarding occupation and childhood sunburns, which were based on the patients’ memory and therefore potentially biased. Data regarding family history of BCC also was self-reported and not validated. Another limiting factor was that other non-UV risk factors for BCC, such as ionizing radiation exposure, were not considered. The limited sample size also may have impacted the study results. Among the strengths of the study are the complete response rate, the similar catchment area of OWs and IWs, the common hospital setting of the 2 cohorts, and the similar attention to medical history. All patients were obtained from the practice of a single referral dermatologist and are felt to be representative of our working area. The use of a single dermatologist reduces provider-associated variability.

Conclusion

According to the results of this study, OWs are more likely to develop nodular BCCs with no increased risk for superficial BCCs. The age of onset in OWs is older than in IWs. Some anatomical sites such as the trunk are more commonly affected in IWs. Truncal BCCs may have etiological factors other than UV exposure, such as a genetic predisposition. This study is useful to occupational safety representatives and physicians to stimulate the implementation of prevention strategies for this easily preventable malignancy and may encourage further research.

Basal cell carcinoma (BCC) is the most prevalent malignancy in white individuals and its incidence is rapidly increasing. Despite its low mortality rate, BCC can cause severe morbidity and remains a serious health problem with a high economic burden for health care systems. The incidence of BCC is higher in individuals who have red or blonde hair, light eye color, and/or Fitzpatrick skin types I and II. The risk for developing BCC also increases with age, and men are more frequently affected than women.^1,2 Although several factors have been implicated in the etiology of this condition, such as exposure to ionizing radiation, trauma, chemical carcinogenesis, immunosuppression, predisposing syndromes, and host factors (eg, traits that affect susceptibility to disease),^3-5 exposure to UV radiation is considered to be a major risk factor, with most BCCs presenting in sun-exposed areas of the body (eg, face, neck). Prolongate suberythrodermal UV doses, which do not burn the skin but cause erythema in the histological level, can lead to formation of pyrimidine dimers in the dermal and epidermal tissues and cause DNA mutation with potential carcinogenic effects. Due to a large number of outdoor occupations, it is likely that outdoor workers (OWs) with a history of UV exposure may develop BCCs with different features than those seen in indoor workers (IWs). However, there has been debate about the relevance of occupational UV exposure as a risk factor for BCC development.^6,7 The aim of this study was to compare the clinical and histological features of BCCs in OWs versus IWs at a referral hospital in southern Spain.

Methods

Using the electronic pathology records at a referral hospital in southern Spain, we identified medical records between May 1, 2010, and May 1, 2011, of specimens containing the term skin in the specimen box and basal cell carcinoma in the diagnosis box. We excluded patients with a history of or concomitant squamous cell carcinoma. Reexcision of incompletely excised lesions; punch, shave or incisional biopsies; and palliative excisions also were excluded. The specimens were reviewed and classified according to the differentiation pattern of BCC (ie, nodular, superficial, morpheic, micronodular). Basal cell carcinomas with mixed features were classified according to the most predominant subtype.

We also gathered information regarding the patients’ work history (ie, any job held during their lifetime with a minimum duration of 6 months). Patients were asked about the type of work and start/end dates. In patients who performed OW, we evaluated hours per day and months as well as the type of clothing worn (eg, head covering, socks/stockings during work in the summer months).

Each patient was classified as an OW or IW based on his/her stated occupation. The OWs included those who performed all or most of their work (≥6 hours per day for at least 6 months) outdoors in direct sunlight. Most patients in this group included farmers and fishermen. Indoor workers were those who performed most of their work in an indoor environment (eg, shop, factory, office, hospital, library, bank, school, laboratory). Most patients in this group included mechanics and shop assistants. A small group of individuals could not be classified as OWs or IWs and therefore were excluded from the study. Individuals with a history of exposure to ionizing radiation, chemical carcinogenesis, immunosuppression, or predisposing syndromes also were excluded.

We included variables that could be considered independent risk factors for BCC, including age, sex, eye color, natural hair color, Fitzpatrick skin type, history of sunburns, and family history. All data were collected via a personal interview performed by a single dermatologist (H.H-E.) during the follow-up with the patients conducted after obtaining all medical records and contacting eligible patients; none of the patients were lost on follow-up.

The study was approved by the hospital’s ethics committee and written consent was obtained from all recruited patients for analyzing the data acquired and accessing the relevant diagnostic documents (eg, pathology reports).

The cohorts were compared by a χ² test and Student t test, which were performed using the SPSS software version 15. Statistical significance was determined using α=.05, and all tests were 2-sided.

Results

A total of 308 patients were included in the study, comprising 178 (58%) OWs and 130 (42%) IWs. Table 1 summarizes the characteristics of each cohort with the statistical outcomes.

The mean age (SD) of the OWs was significantly higher than the IWs (75.17 [10.74] vs 69.73 [9.98] years; P<.001). The sex distribution among the 2 cohorts was significantly different (P=.002); the OW group featured a slightly higher proportion of men than women (92 [52%] vs 86 [48%]), whereas women were clearly more prevalent in the IW group than men (85 [65%] vs 45 [35%]).

No significant differences regarding eye color (blue/gray vs brown/black) between the 2 cohorts were found (P>.05). In the same way, the 2 cohorts did not show differences in the natural hair color (red/blonde vs brown/black)(P>.05).

Fitzpatrick skin type II was the most common between both cohorts (82 [46%] OWs and 75 [58%] IWs), but no statistical differences regarding the proportions of each skin type were found (P>.05).

History of sunburns (>2 episodes) was significantly different between the 2 cohorts. The incidence of second-degree sunburns in childhood was higher in IWs (P<.00001), while the incidence of second-degree sunburns in adulthood was higher in OWs (P=.002).

Most OWs had a positive family history of BCC (101 [57%]), while the majority of IWs had a negative family history of BCC (90 [69%]). This difference was statistically significant (P=.03).

Table 2 shows the distribution of anatomic sites of BCCs in OWs and IWs. The nose was the most frequently affected area in OWs (35 cases [20%]), while the cheek was the most common location (23 [18%]) in IWs. Comparison of the frequency of BCC incidence for each anatomic location revealed that only the rate for truncal BCC was significantly different; IWs had a higher incidence of truncal BCCs than OWs (P=.0035). Although the differences between groups were not statistically significant, there was a trend toward a higher incidence of BCCs on the forehead in OW (P=.06).

In both cohorts, the most prevalent histologic subtype was nodular BCC (133 [75%] OWs and 88 [68%] IWs), followed by superficial BCC (17 [10%] OWs and 27 [21%] IWs). The incidence rate of nodular BCCs was statistically different between the 2 cohorts, with OWs showing a higher incidence compared to IWs (P=.024). Regarding the superficial subtype, the opposite was observed: IWs had significantly increased risk compared to OWs (P=.05). There was a trend toward a higher incidence of morpheic BCCs in OWs than IWs, but the difference was not statistically significant (P=.07).

Comment

Skin cancer due to occupational UV exposure is more common than is generally recognized,^6,7 but occupational UV exposure as a risk factor for BCC is still an ongoing debate. In this study, we analyzed the different clinical and histological features of BCC in OWs versus IWs.

The geographic area where this study was performed is characterized by a subtropical Mediterranean climate with irregular rainfall; a short, cool to mild winter; and long, dry, hot summers. Summer temperatures usually are hot and regularly exceed 35°C (95°F). UV index (UVI) is a measure of the amount of skin-damaging UV radiation expected to reach the earth’s surface when the sun is highest in the sky (around midday) and ranges from 1 (low risk) to 10 (maximum risk). In southern Spain, the mean UVI is approximately 6 and can reach up to 9 or sometimes 10 in the summer months. Although Fitzpatrick skin types II and III are most common, the elevated UVI indicates that the general population in southern Spain is at a high risk for developing skin cancer.

In our study the mean age of IWs was lower than OWs, which suggests that IWs may develop BCC at a younger age than OWs. This finding is consistent with studies showing that cumulative occupational UV exposure has been associated with development of BCCs in older age groups, while acute intermittent recreational sun exposure, particularly sustained in childhood and adolescence, is linked with BCC in younger patients.⁶

The role of sex as a risk factor for BCC remains unclear. Some reports show that BCC is more common in men than in women.^8-10 In our study, sex distribution was statistically significant (P=.002); there were more women in the IW cohort and more men in the OW cohort. These differences may be explained by cultural and lifestyle patterns, as women who are IWs tend to have office jobs in urban settings and wear modern fashion clothes at work and for recreation. In rural settings, women have agricultural jobs and tend to wear more traditional clothes that offer sun protection.

Positive family history has been suggested to be a constitutional risk factor for BCC development.^8,11,12 In our study, we observed that positive family history was more common in OWs, while most IWs had a negative family history. These differences were significant (P=.03), and OWs had a 2.6-fold increased likelihood of having a positive family history of BCC compared to IWs. Cultural and lifestyle patterns may partially explain this finding. In rural settings, workers tend to have the same job as their parents as a traditional way of life and therefore have similar patterns of UV exposure; in urban settings, individuals may have different jobs than their parents and therefore the pattern of UV exposure may be different. However, a genetic predisposition for developing BCC cannot be excluded. In addition, we have to consider that the information on family history of BCC in the patients was self-reported and not validated, which may limit the results.

The difference in history of second-degree sunburn in childhood was significantly higher in IWs than in OWs (P<.00001). The OW group had a significant rate of sunburns in adulthood (P=.002). The relationship between UV radiation and BCC is complex, and the patterns of sun exposure and their occurrence in different periods of lifetime (ie, childhood vs adulthood) remain controversial.¹³ The overall history of severe sunburns seems to be more important than simply the tendency to burn or tan,^14,15 and a history of sunburns in childhood and adolescence has been associated with early-onset BCC.⁶ Our findings were consistent in that the age of onset of BCCs was lower in IWs who had a history of sunburns in childhood. Basal cell carcinomas developed at older ages in OWs who had a higher incidence of sunburns in adulthood. However, we have to consider that the retrospective nature of the data collection on sunburns in childhood and adulthood was potentially limited, as the information was based on the patients’ memory. Additionally, other non-UV risk factors for BCC, such as ionizing radiation exposure, were not analyzed.

The majority of BCCs developed in sun-exposed areas of the head and neck in both cohorts, and only 35 (20%) and 28 (22%) BCCs were located on the trunk, arms, or legs in OWs and IWs, respectively. In our study, the rate of BCCs on the trunk was significantly lower in OWs than in IWs (P=.0035). Basal cell carcinomas on the trunk have been suggested to be linked to genetic susceptibility^16,17 and reduced DNA repair capacity¹⁸ rather than sun exposure. Our findings support this hypothesis and suggest that occupational sun exposure has no direct relation with truncal BCC. This outcome is consistent with the result of a case-control study conducted by Pelucchi et al¹⁹ (N=1040). The authors concluded that occupational UV exposure was not associated with truncal BCC development but with head/neck BCC, indicating that there may be different etiological mechanisms between truncal and head/neck BCC.¹⁹ In the largest BCC case series published in the literature with 13,457 specimens, the authors stated that tumors on the trunk may represent a particular variant of BCC, in which the theory of chronic versus intermittent UV exposure cannot be simply extrapolated as it is for the rest of BCC sites. Other factors such as genetic predisposition could be involved in the development of truncal BCC.²⁰ Similarly, Ramos et al²¹ suggested that nonmelanoma skin cancers in sun-protected anatomic sites may occur in individuals with impairment in the DNA repair process.

The classification of histological subtypes of BCC helps to predict tumor behavior,²² which can impact the prognosis. In our study, nodular BCC was the most common subtype in both cohorts, followed by superficial BCC. The nodular subtype was increased in OWs compared to IWs, while the superficial subtype was most common in IWs. Bastiaens et al²³ and McCormack et al²⁴ have suggested that the most frequent subtypes of BCC (nodular and superficial) may represent different tumors with distinct causal factors. According to these authors, nodular subtypes are associated with cumulative UV exposure, while superficial subtypes are associated with more intense and intermittent UV exposure. The results of the current study support this hypothesis, as the OW cohort with cumulative UV exposure showed more incidence of nodular BCC than IWs, while the patients with intense and intermittent sun exposure (the IWs) showed more risk of superficial BCC.

The importance of occupational UV exposure in OWs as a risk factor for BCC is still an ongoing discussion. Our data show that occupational UV exposure may be considered an etiological factor for BCC according to histological subtype and anatomic site. Our study is limited by the retrospective nature of the data collection regarding occupation and childhood sunburns, which were based on the patients’ memory and therefore potentially biased. Data regarding family history of BCC also was self-reported and not validated. Another limiting factor was that other non-UV risk factors for BCC, such as ionizing radiation exposure, were not considered. The limited sample size also may have impacted the study results. Among the strengths of the study are the complete response rate, the similar catchment area of OWs and IWs, the common hospital setting of the 2 cohorts, and the similar attention to medical history. All patients were obtained from the practice of a single referral dermatologist and are felt to be representative of our working area. The use of a single dermatologist reduces provider-associated variability.

Conclusion

According to the results of this study, OWs are more likely to develop nodular BCCs with no increased risk for superficial BCCs. The age of onset in OWs is older than in IWs. Some anatomical sites such as the trunk are more commonly affected in IWs. Truncal BCCs may have etiological factors other than UV exposure, such as a genetic predisposition. This study is useful to occupational safety representatives and physicians to stimulate the implementation of prevention strategies for this easily preventable malignancy and may encourage further research.

Adverse drug reactions account for 3% to 6% of hospital admissions in the United States and occur in 10% to 15% of hospitalized patients.^1,2 The most common culprits are antibiotics and nonsteroidal anti-inflammatory drugs (NSAIDs).^3-12 In most cases, diagnoses are made clinically without diagnostic testing. To identify drug allergies associated with diagnostic testing, one center selected patients with suspected cutaneous drug reactions (2006-2010) for further evaluation.¹³ Of 612 patients who were evaluated, 141 had a high suspicion of drug allergy and were included in the analysis. The excluded patients had pseudoallergic reactions, reactive exanthemas due to infection, histopathologic exclusion of drug allergy, angioedema, or other dermatological conditions such as contact dermatitis and eczema. Of the included patients, 107 were diagnosed with drug reactions, while the remainder had non–drug-related exanthemas or unknown etiology after testing. Identified culprit drugs were predominantly antibiotics (39.8%) and NSAIDs (21.2%); contrast media, anticoagulants, anticonvulsants, antimalarials, antifungals, glucocorticoids, antihypertensives, and proton pump inhibitors also were implicated. They were identified with skin prick, intradermal, and patch tests (62.6%); lymphocyte transformation test (17.7%); oral rechallenge (5.6%); or without skin testing (6.5%). One quarter of patients with a high suspicion for drug allergy did not have a confirmed drug eruption in this study. Another study found that 10% to 20% of patients with reported penicillin allergy had confirmation via skin prick testing.¹⁴ These findings suggest that confirmation of suspected drug allergy may require more than one diagnostic test.

Tests for Adverse Drug Reactions

The following tests have been shown to aid in the identification of cutaneous drug eruptions: (1) patch tests^15-21; (2) intradermal tests^14,15,19,20; (3) drug provocation tests^15,20; and (4) lymphocyte transformation tests.²⁰ Intradermal or skin prick tests are most useful in urticarial eruptions but can be considered in nonurticarial eruptions with delayed inspection of test sites up to 1 week after testing. Drug provocation tests are considered the gold standard but involve patient risk. Lymphocyte transformation tests use the principle that T lymphocytes proliferate in the presence of drugs to which the patient is sensitized. Patch tests will be discussed in greater detail below. Immunohistochemistry can determine immunologic mechanisms of eruptions but cannot identify causative agents.^16,17,22

A retrospective study of patients referred for evaluation of adverse drug reactions between 1996 and 2006 found the collective negative predictive value (NPV)—the percentage of truly negative skin tests based on provocation or substitution testing—of cutaneous drug tests including patch, prick, and intradermal tests to be 89.6% (95% confidence interval, 85.9%-93.3%).²³ The NPVs of each test were not reported. Patients with negative cutaneous tests had subsequent oral rechallenge or substitution testing with medication from the same drug class.²³ Another study¹⁶ found the NPV of patch testing to be at least 79% after review of data from other studies using patch and provocation testing.^16,24 These studies suggest that cutaneous testing can be useful, albeit imperfect, in the evaluation and diagnosis of drug allergy.

Review of the Patch Test

Patch tests can be helpful in diagnosis of delayed hypersensitivities.¹⁸ Patch testing is most commonly and effectively used to diagnose allergic contact dermatitis, but its utility in other applications, such as diagnosis of cutaneous drug eruptions, has not been extensively studied.

The development of patch tests to diagnose systemic drug allergies is inhibited by the uncertainty of percutaneous drug penetration, a dearth of studies to determine the best test concentrations of active drug in the patch test, and the potential for nonimmunologic contact urticaria upon skin exposure. Furthermore, cutaneous metabolism of many antigens is well documented, but correlation to systemic metabolism often is unknown, which can confound patch test results and lead to false-negative results when the skin’s metabolic capacity does not match the body’s capacity to generate antigens capable of eliciting immunogenic responses.²¹ Additionally, the method used to suspend and disperse drugs in patch test vehicles is unfamiliar to most pharmacists, and standardized concentrations and vehicles are available only for some medications.²⁵ Studies sufficient to obtain US Food and Drug Administration approval of patch tests for systemic drug eruptions would be costly and therefore prohibitive to investigators. The majority of the literature consists of case reports and data extrapolated from reviews. Patch test results of many drugs have been reported in the literature, with the highest frequencies of positive results associated with anticonvulsants,²⁶ antibiotics, corticosteroids, calcium channel blockers, and benzodiazepines.²¹

Patch test placement affects the diagnostic value of the test. Placing patch tests on previously involved sites of fixed drug eruptions improves yield over placement on uninvolved skin.²⁷ Placing patch tests on previously involved sites of other drug eruptions such as toxic epidermal necrolysis also may aid in diagnosis, though the literature is sparse.^25,26,28

Patch Testing in Drug Eruptions

Morbilliform eruptions account for 48% to 91% of patients with adverse drug reactions.^4-6 Other drug eruptions include urticarial eruptions, acute generalized exanthematous pustulosis (AGEP), drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome, toxic epidermal necrolysis, Stevens-Johnson syndrome, lichenoid drug eruption, symmetric drug-related intertriginous and flexural exanthema (SDRIFE), erythema multiforme (EM), and systemic contact dermatitis. The Table summarizes reports of positive patch tests with various medications for these drug eruptions.

In general, antimicrobials and NSAIDs were the most implicated drugs with positive patch test results in AGEP, DRESS syndrome, EM, fixed drug eruptions, and morbilliform eruptions. In AGEP, positive results also were reported for other drugs, including terbinafine and morphine.^29-38 In fixed drug eruptions, patch testing on involved skin showed positive results to NSAIDs, analgesics, platelet inhibitors, and antimicrobials.^27,52-55 Patch testing in DRESS syndrome has shown many positive reactions to antiepileptics and antipsychotics.^39-43 One study used patch tests in SDRIFE, reporting positive results with antimicrobials, antineoplastics, decongestants, and glucocorticoids.⁶¹ Nonsteroidal anti-inflammatory drugs, antimicrobials, calcium channel blockers, and histamine antagonists were implicated in EM.^47-51 Positive patch tests were seen in morbilliform eruptions with selective serotonin reuptake inhibitors, antiepileptics/benzodiazepines, NSAIDs, and antimicrobials.^28,57-60 In toxic epidermal necrolysis, diagnosis with patch testing was made using patches placed on previously involved skin with sulfamethoxazole.⁶²

Systemic Contact Dermatitis

Drugs historically recognized as causing allergic contact dermatitis (eg, topical gentamycin) can cause systemic contact dermatitis, which can be patch tested. In these situations, systemic contact dermatitis may be due to either the active drug or excipients in the medication formulation. Excipients are inactive ingredients in medications that provide a suitable consistency, appearance, or form. Often overlooked as culprits of drug hypersensitivity because they are theoretically inert, excipients are increasingly implicated in drug allergy. Swerlick and Campbell⁶³ described 11 cases in which chronic unexplained pruritus responded to medication changes to avoid coloring agents. The most common culprits were FD&C Blue No. 1 and FD&C Blue No. 2. Patch testing for allergies to dyes can be clinically useful, though a lack of commercially available patch tests makes diagnosis difficult.⁶⁴

Other excipients can cause cutaneous reactions. Propylene glycol, commonly implicated in allergic contact dermatitis, also can cause cutaneous eruptions upon systemic exposure.⁶⁵ Corticosteroid-induced systemic contact dermatitis has been reported, though it is less prevalent than allergic contact dermatitis.⁶⁶ These reactions usually are due to nonmethylated and nonhalogenated corticosteroids including budesonide, cortisone, hydrocortisone, prednisolone, and methylprednisolone.^67,68 Patch testing in these situations is complicated by the possibility of false-negative results due to the anti-inflammatory effects of the corticosteroids. Therefore, patch testing should be performed using standardized and not treatment concentrations.

In our clinic, we have anecdotally observed several patients with chronic dermatitis and suspected NSAID allergies have positive patch test results with propylene glycol and not the suspected drug. Excipients encountered in multiple drugs and foods are more likely to present as chronic dermatitis, while active drug ingredients started in hospital settings more often present as acute dermatitis.

Our Experience

We have patch tested a handful of patients with suspected drug eruptions (University Hospitals Cleveland Medical Center institutional review board #07-12-27). Medications, excipients, and their concentrations (in % weight per weight) and vehicles that were tested include ibuprofen (10% petrolatum), aspirin (10% petrolatum), hydrochlorothiazide (10% petrolatum), captopril (5% petrolatum), and propylene glycol (30% water or 5% petrolatum). Patch tests were read at 48 and 72 hours and scored according to the International Contact Dermatitis Research Group patch test scoring guidelines.⁶⁹ Two patients tested for ibuprofen reacted positively only to propylene glycol; the 3 other patients did not react to aspirin, hydrochlorothiazide, and captopril. Overall, we observed no positive patch tests to medications and 2 positive tests to propylene glycol in 5 patients tested (unpublished data).

Areas of Uncertainty

Although tests for immediate-type hypersensitivity reactions to drugs exist as skin prick tests, diagnostic testing for the majority of drug reactions does not exist. Drug allergy diagnosis is made with history and temporality, potentially resulting in unnecessary avoidance of helpful medications. Ideal patch test concentrations and vehicles as well as the sensitivity and specificity of these tests are unknown.

Guidelines From Professional Societies

Drug allergy testing guidelines are available from the British Society for Allergy and Clinical Immunology⁷⁰ and American Academy of Allergy, Asthma and Immunology.⁷¹ The guidelines recommend diagnosis by history and temporality, and it is stated that patch testing is potentially useful in maculopapular rashes, AGEP, fixed drug eruptions, and DRESS syndrome.

Conclusion

Case reports in the literature suggest the utility of patch testing in some drug allergies. We suggest testing excipients such as propylene glycol and benzoic acid to rule out systemic contact dermatitis when patch testing with active drugs to confirm cause of suspected adverse cutaneous reactions to medications.

Adverse drug reactions account for 3% to 6% of hospital admissions in the United States and occur in 10% to 15% of hospitalized patients.^1,2 The most common culprits are antibiotics and nonsteroidal anti-inflammatory drugs (NSAIDs).^3-12 In most cases, diagnoses are made clinically without diagnostic testing. To identify drug allergies associated with diagnostic testing, one center selected patients with suspected cutaneous drug reactions (2006-2010) for further evaluation.¹³ Of 612 patients who were evaluated, 141 had a high suspicion of drug allergy and were included in the analysis. The excluded patients had pseudoallergic reactions, reactive exanthemas due to infection, histopathologic exclusion of drug allergy, angioedema, or other dermatological conditions such as contact dermatitis and eczema. Of the included patients, 107 were diagnosed with drug reactions, while the remainder had non–drug-related exanthemas or unknown etiology after testing. Identified culprit drugs were predominantly antibiotics (39.8%) and NSAIDs (21.2%); contrast media, anticoagulants, anticonvulsants, antimalarials, antifungals, glucocorticoids, antihypertensives, and proton pump inhibitors also were implicated. They were identified with skin prick, intradermal, and patch tests (62.6%); lymphocyte transformation test (17.7%); oral rechallenge (5.6%); or without skin testing (6.5%). One quarter of patients with a high suspicion for drug allergy did not have a confirmed drug eruption in this study. Another study found that 10% to 20% of patients with reported penicillin allergy had confirmation via skin prick testing.¹⁴ These findings suggest that confirmation of suspected drug allergy may require more than one diagnostic test.

Tests for Adverse Drug Reactions

The following tests have been shown to aid in the identification of cutaneous drug eruptions: (1) patch tests^15-21; (2) intradermal tests^14,15,19,20; (3) drug provocation tests^15,20; and (4) lymphocyte transformation tests.²⁰ Intradermal or skin prick tests are most useful in urticarial eruptions but can be considered in nonurticarial eruptions with delayed inspection of test sites up to 1 week after testing. Drug provocation tests are considered the gold standard but involve patient risk. Lymphocyte transformation tests use the principle that T lymphocytes proliferate in the presence of drugs to which the patient is sensitized. Patch tests will be discussed in greater detail below. Immunohistochemistry can determine immunologic mechanisms of eruptions but cannot identify causative agents.^16,17,22

A retrospective study of patients referred for evaluation of adverse drug reactions between 1996 and 2006 found the collective negative predictive value (NPV)—the percentage of truly negative skin tests based on provocation or substitution testing—of cutaneous drug tests including patch, prick, and intradermal tests to be 89.6% (95% confidence interval, 85.9%-93.3%).²³ The NPVs of each test were not reported. Patients with negative cutaneous tests had subsequent oral rechallenge or substitution testing with medication from the same drug class.²³ Another study¹⁶ found the NPV of patch testing to be at least 79% after review of data from other studies using patch and provocation testing.^16,24 These studies suggest that cutaneous testing can be useful, albeit imperfect, in the evaluation and diagnosis of drug allergy.

Review of the Patch Test

Patch tests can be helpful in diagnosis of delayed hypersensitivities.¹⁸ Patch testing is most commonly and effectively used to diagnose allergic contact dermatitis, but its utility in other applications, such as diagnosis of cutaneous drug eruptions, has not been extensively studied.

The development of patch tests to diagnose systemic drug allergies is inhibited by the uncertainty of percutaneous drug penetration, a dearth of studies to determine the best test concentrations of active drug in the patch test, and the potential for nonimmunologic contact urticaria upon skin exposure. Furthermore, cutaneous metabolism of many antigens is well documented, but correlation to systemic metabolism often is unknown, which can confound patch test results and lead to false-negative results when the skin’s metabolic capacity does not match the body’s capacity to generate antigens capable of eliciting immunogenic responses.²¹ Additionally, the method used to suspend and disperse drugs in patch test vehicles is unfamiliar to most pharmacists, and standardized concentrations and vehicles are available only for some medications.²⁵ Studies sufficient to obtain US Food and Drug Administration approval of patch tests for systemic drug eruptions would be costly and therefore prohibitive to investigators. The majority of the literature consists of case reports and data extrapolated from reviews. Patch test results of many drugs have been reported in the literature, with the highest frequencies of positive results associated with anticonvulsants,²⁶ antibiotics, corticosteroids, calcium channel blockers, and benzodiazepines.²¹

Patch test placement affects the diagnostic value of the test. Placing patch tests on previously involved sites of fixed drug eruptions improves yield over placement on uninvolved skin.²⁷ Placing patch tests on previously involved sites of other drug eruptions such as toxic epidermal necrolysis also may aid in diagnosis, though the literature is sparse.^25,26,28

Patch Testing in Drug Eruptions

Morbilliform eruptions account for 48% to 91% of patients with adverse drug reactions.^4-6 Other drug eruptions include urticarial eruptions, acute generalized exanthematous pustulosis (AGEP), drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome, toxic epidermal necrolysis, Stevens-Johnson syndrome, lichenoid drug eruption, symmetric drug-related intertriginous and flexural exanthema (SDRIFE), erythema multiforme (EM), and systemic contact dermatitis. The Table summarizes reports of positive patch tests with various medications for these drug eruptions.

In general, antimicrobials and NSAIDs were the most implicated drugs with positive patch test results in AGEP, DRESS syndrome, EM, fixed drug eruptions, and morbilliform eruptions. In AGEP, positive results also were reported for other drugs, including terbinafine and morphine.^29-38 In fixed drug eruptions, patch testing on involved skin showed positive results to NSAIDs, analgesics, platelet inhibitors, and antimicrobials.^27,52-55 Patch testing in DRESS syndrome has shown many positive reactions to antiepileptics and antipsychotics.^39-43 One study used patch tests in SDRIFE, reporting positive results with antimicrobials, antineoplastics, decongestants, and glucocorticoids.⁶¹ Nonsteroidal anti-inflammatory drugs, antimicrobials, calcium channel blockers, and histamine antagonists were implicated in EM.^47-51 Positive patch tests were seen in morbilliform eruptions with selective serotonin reuptake inhibitors, antiepileptics/benzodiazepines, NSAIDs, and antimicrobials.^28,57-60 In toxic epidermal necrolysis, diagnosis with patch testing was made using patches placed on previously involved skin with sulfamethoxazole.⁶²

Systemic Contact Dermatitis

Drugs historically recognized as causing allergic contact dermatitis (eg, topical gentamycin) can cause systemic contact dermatitis, which can be patch tested. In these situations, systemic contact dermatitis may be due to either the active drug or excipients in the medication formulation. Excipients are inactive ingredients in medications that provide a suitable consistency, appearance, or form. Often overlooked as culprits of drug hypersensitivity because they are theoretically inert, excipients are increasingly implicated in drug allergy. Swerlick and Campbell⁶³ described 11 cases in which chronic unexplained pruritus responded to medication changes to avoid coloring agents. The most common culprits were FD&C Blue No. 1 and FD&C Blue No. 2. Patch testing for allergies to dyes can be clinically useful, though a lack of commercially available patch tests makes diagnosis difficult.⁶⁴

Other excipients can cause cutaneous reactions. Propylene glycol, commonly implicated in allergic contact dermatitis, also can cause cutaneous eruptions upon systemic exposure.⁶⁵ Corticosteroid-induced systemic contact dermatitis has been reported, though it is less prevalent than allergic contact dermatitis.⁶⁶ These reactions usually are due to nonmethylated and nonhalogenated corticosteroids including budesonide, cortisone, hydrocortisone, prednisolone, and methylprednisolone.^67,68 Patch testing in these situations is complicated by the possibility of false-negative results due to the anti-inflammatory effects of the corticosteroids. Therefore, patch testing should be performed using standardized and not treatment concentrations.

In our clinic, we have anecdotally observed several patients with chronic dermatitis and suspected NSAID allergies have positive patch test results with propylene glycol and not the suspected drug. Excipients encountered in multiple drugs and foods are more likely to present as chronic dermatitis, while active drug ingredients started in hospital settings more often present as acute dermatitis.

Our Experience

We have patch tested a handful of patients with suspected drug eruptions (University Hospitals Cleveland Medical Center institutional review board #07-12-27). Medications, excipients, and their concentrations (in % weight per weight) and vehicles that were tested include ibuprofen (10% petrolatum), aspirin (10% petrolatum), hydrochlorothiazide (10% petrolatum), captopril (5% petrolatum), and propylene glycol (30% water or 5% petrolatum). Patch tests were read at 48 and 72 hours and scored according to the International Contact Dermatitis Research Group patch test scoring guidelines.⁶⁹ Two patients tested for ibuprofen reacted positively only to propylene glycol; the 3 other patients did not react to aspirin, hydrochlorothiazide, and captopril. Overall, we observed no positive patch tests to medications and 2 positive tests to propylene glycol in 5 patients tested (unpublished data).

Areas of Uncertainty

Although tests for immediate-type hypersensitivity reactions to drugs exist as skin prick tests, diagnostic testing for the majority of drug reactions does not exist. Drug allergy diagnosis is made with history and temporality, potentially resulting in unnecessary avoidance of helpful medications. Ideal patch test concentrations and vehicles as well as the sensitivity and specificity of these tests are unknown.

Guidelines From Professional Societies

Drug allergy testing guidelines are available from the British Society for Allergy and Clinical Immunology⁷⁰ and American Academy of Allergy, Asthma and Immunology.⁷¹ The guidelines recommend diagnosis by history and temporality, and it is stated that patch testing is potentially useful in maculopapular rashes, AGEP, fixed drug eruptions, and DRESS syndrome.

Conclusion

Case reports in the literature suggest the utility of patch testing in some drug allergies. We suggest testing excipients such as propylene glycol and benzoic acid to rule out systemic contact dermatitis when patch testing with active drugs to confirm cause of suspected adverse cutaneous reactions to medications.

Adverse drug reactions account for 3% to 6% of hospital admissions in the United States and occur in 10% to 15% of hospitalized patients.^1,2 The most common culprits are antibiotics and nonsteroidal anti-inflammatory drugs (NSAIDs).^3-12 In most cases, diagnoses are made clinically without diagnostic testing. To identify drug allergies associated with diagnostic testing, one center selected patients with suspected cutaneous drug reactions (2006-2010) for further evaluation.¹³ Of 612 patients who were evaluated, 141 had a high suspicion of drug allergy and were included in the analysis. The excluded patients had pseudoallergic reactions, reactive exanthemas due to infection, histopathologic exclusion of drug allergy, angioedema, or other dermatological conditions such as contact dermatitis and eczema. Of the included patients, 107 were diagnosed with drug reactions, while the remainder had non–drug-related exanthemas or unknown etiology after testing. Identified culprit drugs were predominantly antibiotics (39.8%) and NSAIDs (21.2%); contrast media, anticoagulants, anticonvulsants, antimalarials, antifungals, glucocorticoids, antihypertensives, and proton pump inhibitors also were implicated. They were identified with skin prick, intradermal, and patch tests (62.6%); lymphocyte transformation test (17.7%); oral rechallenge (5.6%); or without skin testing (6.5%). One quarter of patients with a high suspicion for drug allergy did not have a confirmed drug eruption in this study. Another study found that 10% to 20% of patients with reported penicillin allergy had confirmation via skin prick testing.¹⁴ These findings suggest that confirmation of suspected drug allergy may require more than one diagnostic test.

Tests for Adverse Drug Reactions

The following tests have been shown to aid in the identification of cutaneous drug eruptions: (1) patch tests^15-21; (2) intradermal tests^14,15,19,20; (3) drug provocation tests^15,20; and (4) lymphocyte transformation tests.²⁰ Intradermal or skin prick tests are most useful in urticarial eruptions but can be considered in nonurticarial eruptions with delayed inspection of test sites up to 1 week after testing. Drug provocation tests are considered the gold standard but involve patient risk. Lymphocyte transformation tests use the principle that T lymphocytes proliferate in the presence of drugs to which the patient is sensitized. Patch tests will be discussed in greater detail below. Immunohistochemistry can determine immunologic mechanisms of eruptions but cannot identify causative agents.^16,17,22

A retrospective study of patients referred for evaluation of adverse drug reactions between 1996 and 2006 found the collective negative predictive value (NPV)—the percentage of truly negative skin tests based on provocation or substitution testing—of cutaneous drug tests including patch, prick, and intradermal tests to be 89.6% (95% confidence interval, 85.9%-93.3%).²³ The NPVs of each test were not reported. Patients with negative cutaneous tests had subsequent oral rechallenge or substitution testing with medication from the same drug class.²³ Another study¹⁶ found the NPV of patch testing to be at least 79% after review of data from other studies using patch and provocation testing.^16,24 These studies suggest that cutaneous testing can be useful, albeit imperfect, in the evaluation and diagnosis of drug allergy.

Review of the Patch Test

Patch tests can be helpful in diagnosis of delayed hypersensitivities.¹⁸ Patch testing is most commonly and effectively used to diagnose allergic contact dermatitis, but its utility in other applications, such as diagnosis of cutaneous drug eruptions, has not been extensively studied.

The development of patch tests to diagnose systemic drug allergies is inhibited by the uncertainty of percutaneous drug penetration, a dearth of studies to determine the best test concentrations of active drug in the patch test, and the potential for nonimmunologic contact urticaria upon skin exposure. Furthermore, cutaneous metabolism of many antigens is well documented, but correlation to systemic metabolism often is unknown, which can confound patch test results and lead to false-negative results when the skin’s metabolic capacity does not match the body’s capacity to generate antigens capable of eliciting immunogenic responses.²¹ Additionally, the method used to suspend and disperse drugs in patch test vehicles is unfamiliar to most pharmacists, and standardized concentrations and vehicles are available only for some medications.²⁵ Studies sufficient to obtain US Food and Drug Administration approval of patch tests for systemic drug eruptions would be costly and therefore prohibitive to investigators. The majority of the literature consists of case reports and data extrapolated from reviews. Patch test results of many drugs have been reported in the literature, with the highest frequencies of positive results associated with anticonvulsants,²⁶ antibiotics, corticosteroids, calcium channel blockers, and benzodiazepines.²¹

Patch test placement affects the diagnostic value of the test. Placing patch tests on previously involved sites of fixed drug eruptions improves yield over placement on uninvolved skin.²⁷ Placing patch tests on previously involved sites of other drug eruptions such as toxic epidermal necrolysis also may aid in diagnosis, though the literature is sparse.^25,26,28

Patch Testing in Drug Eruptions

Morbilliform eruptions account for 48% to 91% of patients with adverse drug reactions.^4-6 Other drug eruptions include urticarial eruptions, acute generalized exanthematous pustulosis (AGEP), drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome, toxic epidermal necrolysis, Stevens-Johnson syndrome, lichenoid drug eruption, symmetric drug-related intertriginous and flexural exanthema (SDRIFE), erythema multiforme (EM), and systemic contact dermatitis. The Table summarizes reports of positive patch tests with various medications for these drug eruptions.

In general, antimicrobials and NSAIDs were the most implicated drugs with positive patch test results in AGEP, DRESS syndrome, EM, fixed drug eruptions, and morbilliform eruptions. In AGEP, positive results also were reported for other drugs, including terbinafine and morphine.^29-38 In fixed drug eruptions, patch testing on involved skin showed positive results to NSAIDs, analgesics, platelet inhibitors, and antimicrobials.^27,52-55 Patch testing in DRESS syndrome has shown many positive reactions to antiepileptics and antipsychotics.^39-43 One study used patch tests in SDRIFE, reporting positive results with antimicrobials, antineoplastics, decongestants, and glucocorticoids.⁶¹ Nonsteroidal anti-inflammatory drugs, antimicrobials, calcium channel blockers, and histamine antagonists were implicated in EM.^47-51 Positive patch tests were seen in morbilliform eruptions with selective serotonin reuptake inhibitors, antiepileptics/benzodiazepines, NSAIDs, and antimicrobials.^28,57-60 In toxic epidermal necrolysis, diagnosis with patch testing was made using patches placed on previously involved skin with sulfamethoxazole.⁶²

Systemic Contact Dermatitis

Drugs historically recognized as causing allergic contact dermatitis (eg, topical gentamycin) can cause systemic contact dermatitis, which can be patch tested. In these situations, systemic contact dermatitis may be due to either the active drug or excipients in the medication formulation. Excipients are inactive ingredients in medications that provide a suitable consistency, appearance, or form. Often overlooked as culprits of drug hypersensitivity because they are theoretically inert, excipients are increasingly implicated in drug allergy. Swerlick and Campbell⁶³ described 11 cases in which chronic unexplained pruritus responded to medication changes to avoid coloring agents. The most common culprits were FD&C Blue No. 1 and FD&C Blue No. 2. Patch testing for allergies to dyes can be clinically useful, though a lack of commercially available patch tests makes diagnosis difficult.⁶⁴

Other excipients can cause cutaneous reactions. Propylene glycol, commonly implicated in allergic contact dermatitis, also can cause cutaneous eruptions upon systemic exposure.⁶⁵ Corticosteroid-induced systemic contact dermatitis has been reported, though it is less prevalent than allergic contact dermatitis.⁶⁶ These reactions usually are due to nonmethylated and nonhalogenated corticosteroids including budesonide, cortisone, hydrocortisone, prednisolone, and methylprednisolone.^67,68 Patch testing in these situations is complicated by the possibility of false-negative results due to the anti-inflammatory effects of the corticosteroids. Therefore, patch testing should be performed using standardized and not treatment concentrations.

In our clinic, we have anecdotally observed several patients with chronic dermatitis and suspected NSAID allergies have positive patch test results with propylene glycol and not the suspected drug. Excipients encountered in multiple drugs and foods are more likely to present as chronic dermatitis, while active drug ingredients started in hospital settings more often present as acute dermatitis.

Our Experience

We have patch tested a handful of patients with suspected drug eruptions (University Hospitals Cleveland Medical Center institutional review board #07-12-27). Medications, excipients, and their concentrations (in % weight per weight) and vehicles that were tested include ibuprofen (10% petrolatum), aspirin (10% petrolatum), hydrochlorothiazide (10% petrolatum), captopril (5% petrolatum), and propylene glycol (30% water or 5% petrolatum). Patch tests were read at 48 and 72 hours and scored according to the International Contact Dermatitis Research Group patch test scoring guidelines.⁶⁹ Two patients tested for ibuprofen reacted positively only to propylene glycol; the 3 other patients did not react to aspirin, hydrochlorothiazide, and captopril. Overall, we observed no positive patch tests to medications and 2 positive tests to propylene glycol in 5 patients tested (unpublished data).

Areas of Uncertainty

Although tests for immediate-type hypersensitivity reactions to drugs exist as skin prick tests, diagnostic testing for the majority of drug reactions does not exist. Drug allergy diagnosis is made with history and temporality, potentially resulting in unnecessary avoidance of helpful medications. Ideal patch test concentrations and vehicles as well as the sensitivity and specificity of these tests are unknown.

Guidelines From Professional Societies

Drug allergy testing guidelines are available from the British Society for Allergy and Clinical Immunology⁷⁰ and American Academy of Allergy, Asthma and Immunology.⁷¹ The guidelines recommend diagnosis by history and temporality, and it is stated that patch testing is potentially useful in maculopapular rashes, AGEP, fixed drug eruptions, and DRESS syndrome.

Conclusion

Case reports in the literature suggest the utility of patch testing in some drug allergies. We suggest testing excipients such as propylene glycol and benzoic acid to rule out systemic contact dermatitis when patch testing with active drugs to confirm cause of suspected adverse cutaneous reactions to medications.

Relapsing polychondritis (RP) is an autoimmune disease affecting cartilaginous structures such as the ears, respiratory passages, joints, and cardiovascular system.^1,2 In rare cases, the systemic effects of this autoimmune process can cause central nervous system (CNS) involvement such as meningoencephalitis (ME).³ In 2011, Wang et al⁴ described 4 cases of RP with ME and reviewed 24 cases from the literature. We present a case of a man with RP-associated ME that was responsive to steroid treatment. We also provide an updated review of the literature.

Case Report

A 44-year-old man developed gradually worsening bilateral ear pain, headaches, and seizures. He was briefly hospitalized and discharged with levetiracetam and quetiapine. However, his mental status continued to deteriorate and he was subsequently hospitalized 3 months later with confusion, hallucinations, and seizures.

On physical examination the patient was disoriented and unable to form cohesive sentences. He had bilateral tenderness, erythema, and edema of the auricles, which notably spared the lobules (Figure 1). The conjunctivae were injected bilaterally, and joint involvement included bilateral knee tenderness and swelling. Neurologic examination revealed questionable meningeal signs but no motor or sensory deficits. An extensive laboratory workup for the etiology of his altered mental status was unremarkable, except for a mildly elevated white blood cell count in the cerebrospinal fluid with predominantly lymphocytes. No infectious etiologies were identified on laboratory testing, and rheumatologic markers were negative including antinuclear antibody, rheumatoid factor, and anti–Sjögren syndrome antigen A/Sjögren syndrome antigen B. Magnetic resonance imaging revealed nonspecific findings of bilateral T2 hyperdensities in the subcortical white matter; however, cerebral angiography revealed no evidence of vasculitis. A biopsy of the right antihelix revealed prominent perichondritis and a neutrophilic inflammatory infiltrate with several lymphocytes and histiocytes (Figure 2). There was degeneration of the cartilaginous tissue with evidence of pyknotic nuclei, eosinophilia, and vacuolization of the chondrocytes. He was diagnosed with RP on the basis of clinical and histologic inflammation of the auricular cartilage, polyarthritis, and ocular inflammation.

Comment

Auricular inflammation is a hallmark of RP and is present in 83% to 95% of patients.^1,3 The affected ears can appear erythematous to violaceous with tender edema of the auricle that spares the lobules where no cartilage is present. The inflammation can extend into the ear canal and cause hearing loss, tinnitus, and vertigo. Histologically, RP can present with a nonspecific leukocytoclastic vasculitis and inflammatory destruction of the cartilage. Therefore, diagnosis of RP is reliant mainly on clinical characteristics rather than pathologic findings. In 1976, McAdam et al⁵ established diagnostic criteria for RP based on the presence of common clinical manifestations (eg, auricular chondritis, seronegative inflammatory polyarthritis, nasal chondritis, ocular inflammation). Michet et al⁶ later proposed major and minor criteria to classify and diagnose RP based on clinical manifestations. Diagnosis of our patient was confirmed by the presence of auricular chondritis, polyarthritis, and ocular inflammation. Diagnosing RP can be difficult because it has many systemic manifestations that can evoke a broad differential diagnosis. The time to diagnosis in our patient was 3 months, but the mean delay in diagnosis for patients with RP and ME is 2.9 years.⁴

The etiology of RP remains unclear, but current evidence supports an immune-mediated process directed toward proteins found in cartilage. Animal studies have suggested that RP may be driven by antibodies to matrillin 1 and type II collagen. There also may be a familial association with HLA-DR4 and genetic predisposition to autoimmune diseases in individuals affected by RP.^1,3 The pathogenesis of CNS involvement in RP is thought to be due to a localized small vessel vasculitis.^7,8 In our patient, however, cerebral angiography was negative for vasculitis, and thus our case may represent another mechanism for CNS involvement. There have been cases of encephalitis in RP caused by pathways other than CNS vasculitis. Kashihara et al⁹ reported a case of RP with encephalitis associated with antiglutamate receptor antibodies found in the cerebrospinal fluid and blood.

Treatment of RP has been based on pathophysiological considerations rather than empiric data due to its rarity. Relapsing polychondritis has been responsive to steroid treatment in reported cases as well as in our patient; however, in cases in which RP did not respond to steroids, infliximab may be effective for RP with ME.¹⁰ Further research regarding the treatment outcomes of RP with ME may be warranted.

Although rare, additional cases of RP with ME have been reported (Table). Wang et al⁴ described a series of 28 patients with RP and ME from 1960 to 2010. A PubMed search of articles indexed for MEDLINE that were published in the English-language literature from 2010 to 2016 was performed using the search terms relapsing polychondritis and nervous system. Including our patient, RP with ME was reported in 17 additional cases since Wang et al⁴ published their findings. These cases involved adults ranging in age from 44 to 73 years who were mainly men (14/17 [82%]). All of the patients presented with bilateral auricular chondritis, except for a case of unilateral ear involvement reported by Storey et al.¹¹ Common neurologic manifestations included fever, headache, and altered mental status. Motor symptoms ranged from dysarthria and agraphia¹² to hemiparesis.¹³ The mechanism of CNS involvement in RP was not identified in most cases; however, Mattiassich et al¹⁴ documented cerebral vasculitis in their patient, and Niwa et al¹⁶ found diffuse cerebral vasculitis on autopsy. Eleven of 17 (65%) cases responded to steroid treatment. Of the 6 cases in which RP did not respond to steroids, 2 patients died despite high-dose steroid treatment,^11,20 2 responded to infliximab,^10,15 1 responded to tocilizumab,²¹ and 1 was lost to follow-up after initial treatment failure.²⁰

Conclusion

Although rare, RP should not be overlooked in the inpatient setting due to its potential for life-threatening systemic effects. Early diagnosis of this condition may be of benefit to this select population of patients, and further research regarding the prognosis, mechanisms, and treatment of RP may be necessary in the future.

Relapsing polychondritis (RP) is an autoimmune disease affecting cartilaginous structures such as the ears, respiratory passages, joints, and cardiovascular system.^1,2 In rare cases, the systemic effects of this autoimmune process can cause central nervous system (CNS) involvement such as meningoencephalitis (ME).³ In 2011, Wang et al⁴ described 4 cases of RP with ME and reviewed 24 cases from the literature. We present a case of a man with RP-associated ME that was responsive to steroid treatment. We also provide an updated review of the literature.

Case Report

A 44-year-old man developed gradually worsening bilateral ear pain, headaches, and seizures. He was briefly hospitalized and discharged with levetiracetam and quetiapine. However, his mental status continued to deteriorate and he was subsequently hospitalized 3 months later with confusion, hallucinations, and seizures.

On physical examination the patient was disoriented and unable to form cohesive sentences. He had bilateral tenderness, erythema, and edema of the auricles, which notably spared the lobules (Figure 1). The conjunctivae were injected bilaterally, and joint involvement included bilateral knee tenderness and swelling. Neurologic examination revealed questionable meningeal signs but no motor or sensory deficits. An extensive laboratory workup for the etiology of his altered mental status was unremarkable, except for a mildly elevated white blood cell count in the cerebrospinal fluid with predominantly lymphocytes. No infectious etiologies were identified on laboratory testing, and rheumatologic markers were negative including antinuclear antibody, rheumatoid factor, and anti–Sjögren syndrome antigen A/Sjögren syndrome antigen B. Magnetic resonance imaging revealed nonspecific findings of bilateral T2 hyperdensities in the subcortical white matter; however, cerebral angiography revealed no evidence of vasculitis. A biopsy of the right antihelix revealed prominent perichondritis and a neutrophilic inflammatory infiltrate with several lymphocytes and histiocytes (Figure 2). There was degeneration of the cartilaginous tissue with evidence of pyknotic nuclei, eosinophilia, and vacuolization of the chondrocytes. He was diagnosed with RP on the basis of clinical and histologic inflammation of the auricular cartilage, polyarthritis, and ocular inflammation.

Comment

Auricular inflammation is a hallmark of RP and is present in 83% to 95% of patients.^1,3 The affected ears can appear erythematous to violaceous with tender edema of the auricle that spares the lobules where no cartilage is present. The inflammation can extend into the ear canal and cause hearing loss, tinnitus, and vertigo. Histologically, RP can present with a nonspecific leukocytoclastic vasculitis and inflammatory destruction of the cartilage. Therefore, diagnosis of RP is reliant mainly on clinical characteristics rather than pathologic findings. In 1976, McAdam et al⁵ established diagnostic criteria for RP based on the presence of common clinical manifestations (eg, auricular chondritis, seronegative inflammatory polyarthritis, nasal chondritis, ocular inflammation). Michet et al⁶ later proposed major and minor criteria to classify and diagnose RP based on clinical manifestations. Diagnosis of our patient was confirmed by the presence of auricular chondritis, polyarthritis, and ocular inflammation. Diagnosing RP can be difficult because it has many systemic manifestations that can evoke a broad differential diagnosis. The time to diagnosis in our patient was 3 months, but the mean delay in diagnosis for patients with RP and ME is 2.9 years.⁴

The etiology of RP remains unclear, but current evidence supports an immune-mediated process directed toward proteins found in cartilage. Animal studies have suggested that RP may be driven by antibodies to matrillin 1 and type II collagen. There also may be a familial association with HLA-DR4 and genetic predisposition to autoimmune diseases in individuals affected by RP.^1,3 The pathogenesis of CNS involvement in RP is thought to be due to a localized small vessel vasculitis.^7,8 In our patient, however, cerebral angiography was negative for vasculitis, and thus our case may represent another mechanism for CNS involvement. There have been cases of encephalitis in RP caused by pathways other than CNS vasculitis. Kashihara et al⁹ reported a case of RP with encephalitis associated with antiglutamate receptor antibodies found in the cerebrospinal fluid and blood.

Treatment of RP has been based on pathophysiological considerations rather than empiric data due to its rarity. Relapsing polychondritis has been responsive to steroid treatment in reported cases as well as in our patient; however, in cases in which RP did not respond to steroids, infliximab may be effective for RP with ME.¹⁰ Further research regarding the treatment outcomes of RP with ME may be warranted.

Although rare, additional cases of RP with ME have been reported (Table). Wang et al⁴ described a series of 28 patients with RP and ME from 1960 to 2010. A PubMed search of articles indexed for MEDLINE that were published in the English-language literature from 2010 to 2016 was performed using the search terms relapsing polychondritis and nervous system. Including our patient, RP with ME was reported in 17 additional cases since Wang et al⁴ published their findings. These cases involved adults ranging in age from 44 to 73 years who were mainly men (14/17 [82%]). All of the patients presented with bilateral auricular chondritis, except for a case of unilateral ear involvement reported by Storey et al.¹¹ Common neurologic manifestations included fever, headache, and altered mental status. Motor symptoms ranged from dysarthria and agraphia¹² to hemiparesis.¹³ The mechanism of CNS involvement in RP was not identified in most cases; however, Mattiassich et al¹⁴ documented cerebral vasculitis in their patient, and Niwa et al¹⁶ found diffuse cerebral vasculitis on autopsy. Eleven of 17 (65%) cases responded to steroid treatment. Of the 6 cases in which RP did not respond to steroids, 2 patients died despite high-dose steroid treatment,^11,20 2 responded to infliximab,^10,15 1 responded to tocilizumab,²¹ and 1 was lost to follow-up after initial treatment failure.²⁰

Conclusion

Although rare, RP should not be overlooked in the inpatient setting due to its potential for life-threatening systemic effects. Early diagnosis of this condition may be of benefit to this select population of patients, and further research regarding the prognosis, mechanisms, and treatment of RP may be necessary in the future.

Relapsing polychondritis (RP) is an autoimmune disease affecting cartilaginous structures such as the ears, respiratory passages, joints, and cardiovascular system.^1,2 In rare cases, the systemic effects of this autoimmune process can cause central nervous system (CNS) involvement such as meningoencephalitis (ME).³ In 2011, Wang et al⁴ described 4 cases of RP with ME and reviewed 24 cases from the literature. We present a case of a man with RP-associated ME that was responsive to steroid treatment. We also provide an updated review of the literature.

Case Report

A 44-year-old man developed gradually worsening bilateral ear pain, headaches, and seizures. He was briefly hospitalized and discharged with levetiracetam and quetiapine. However, his mental status continued to deteriorate and he was subsequently hospitalized 3 months later with confusion, hallucinations, and seizures.

On physical examination the patient was disoriented and unable to form cohesive sentences. He had bilateral tenderness, erythema, and edema of the auricles, which notably spared the lobules (Figure 1). The conjunctivae were injected bilaterally, and joint involvement included bilateral knee tenderness and swelling. Neurologic examination revealed questionable meningeal signs but no motor or sensory deficits. An extensive laboratory workup for the etiology of his altered mental status was unremarkable, except for a mildly elevated white blood cell count in the cerebrospinal fluid with predominantly lymphocytes. No infectious etiologies were identified on laboratory testing, and rheumatologic markers were negative including antinuclear antibody, rheumatoid factor, and anti–Sjögren syndrome antigen A/Sjögren syndrome antigen B. Magnetic resonance imaging revealed nonspecific findings of bilateral T2 hyperdensities in the subcortical white matter; however, cerebral angiography revealed no evidence of vasculitis. A biopsy of the right antihelix revealed prominent perichondritis and a neutrophilic inflammatory infiltrate with several lymphocytes and histiocytes (Figure 2). There was degeneration of the cartilaginous tissue with evidence of pyknotic nuclei, eosinophilia, and vacuolization of the chondrocytes. He was diagnosed with RP on the basis of clinical and histologic inflammation of the auricular cartilage, polyarthritis, and ocular inflammation.

Comment

Auricular inflammation is a hallmark of RP and is present in 83% to 95% of patients.^1,3 The affected ears can appear erythematous to violaceous with tender edema of the auricle that spares the lobules where no cartilage is present. The inflammation can extend into the ear canal and cause hearing loss, tinnitus, and vertigo. Histologically, RP can present with a nonspecific leukocytoclastic vasculitis and inflammatory destruction of the cartilage. Therefore, diagnosis of RP is reliant mainly on clinical characteristics rather than pathologic findings. In 1976, McAdam et al⁵ established diagnostic criteria for RP based on the presence of common clinical manifestations (eg, auricular chondritis, seronegative inflammatory polyarthritis, nasal chondritis, ocular inflammation). Michet et al⁶ later proposed major and minor criteria to classify and diagnose RP based on clinical manifestations. Diagnosis of our patient was confirmed by the presence of auricular chondritis, polyarthritis, and ocular inflammation. Diagnosing RP can be difficult because it has many systemic manifestations that can evoke a broad differential diagnosis. The time to diagnosis in our patient was 3 months, but the mean delay in diagnosis for patients with RP and ME is 2.9 years.⁴

The etiology of RP remains unclear, but current evidence supports an immune-mediated process directed toward proteins found in cartilage. Animal studies have suggested that RP may be driven by antibodies to matrillin 1 and type II collagen. There also may be a familial association with HLA-DR4 and genetic predisposition to autoimmune diseases in individuals affected by RP.^1,3 The pathogenesis of CNS involvement in RP is thought to be due to a localized small vessel vasculitis.^7,8 In our patient, however, cerebral angiography was negative for vasculitis, and thus our case may represent another mechanism for CNS involvement. There have been cases of encephalitis in RP caused by pathways other than CNS vasculitis. Kashihara et al⁹ reported a case of RP with encephalitis associated with antiglutamate receptor antibodies found in the cerebrospinal fluid and blood.

Treatment of RP has been based on pathophysiological considerations rather than empiric data due to its rarity. Relapsing polychondritis has been responsive to steroid treatment in reported cases as well as in our patient; however, in cases in which RP did not respond to steroids, infliximab may be effective for RP with ME.¹⁰ Further research regarding the treatment outcomes of RP with ME may be warranted.

Although rare, additional cases of RP with ME have been reported (Table). Wang et al⁴ described a series of 28 patients with RP and ME from 1960 to 2010. A PubMed search of articles indexed for MEDLINE that were published in the English-language literature from 2010 to 2016 was performed using the search terms relapsing polychondritis and nervous system. Including our patient, RP with ME was reported in 17 additional cases since Wang et al⁴ published their findings. These cases involved adults ranging in age from 44 to 73 years who were mainly men (14/17 [82%]). All of the patients presented with bilateral auricular chondritis, except for a case of unilateral ear involvement reported by Storey et al.¹¹ Common neurologic manifestations included fever, headache, and altered mental status. Motor symptoms ranged from dysarthria and agraphia¹² to hemiparesis.¹³ The mechanism of CNS involvement in RP was not identified in most cases; however, Mattiassich et al¹⁴ documented cerebral vasculitis in their patient, and Niwa et al¹⁶ found diffuse cerebral vasculitis on autopsy. Eleven of 17 (65%) cases responded to steroid treatment. Of the 6 cases in which RP did not respond to steroids, 2 patients died despite high-dose steroid treatment,^11,20 2 responded to infliximab,^10,15 1 responded to tocilizumab,²¹ and 1 was lost to follow-up after initial treatment failure.²⁰

Conclusion

Although rare, RP should not be overlooked in the inpatient setting due to its potential for life-threatening systemic effects. Early diagnosis of this condition may be of benefit to this select population of patients, and further research regarding the prognosis, mechanisms, and treatment of RP may be necessary in the future.

As employers search for ways to reduce the cost of providing health care to their employees, there is a growing trend toward narrowed provider networks and exclusive laboratory contracts. In the case of clinical pathology, some of these choices make sense from the employer’s perspective. A complete blood cell count or comprehensive metabolic panel is done on a machine and the result is much the same regardless of the laboratory. So why not have all laboratory tests performed by the lowest bidder?

Laboratories vary in quality and anatomic pathology services are different from blood tests. Each slide must be interpreted by a physician and skill in the interpretation of skin specimens varies widely. Dermatopathology was one of the first subspecialties to be recognized within pathology, as it requires a high level of expertise. Clinicopathological correlation often is key to the accurate interpretation of a specimen. The stakes are high, and a delay in diagnosis of melanoma remains one of the most serious errors in medicine and one of the most common causes for litigation in dermatology.

The accurate interpretation of skin biopsy specimens becomes especially difficult when inadequate or misleading clinical information accompanies the specimen. A study of 589 biopsies submitted by primary care physicians and reported by general pathologists demonstrated a 6.5% error rate. False-negative errors were the most common, but false-positives also were observed.¹ A study of pigmented lesions referred to the University of California, San Francisco, demonstrated a discordance rate of 14.3%.² The degree of discordance would be expected to vary based on the range of diagnoses included in each study.

Board-certified dermatopathologists have varying areas of expertise and there is notable subjectivity in the interpretation of biopsy specimens. In the case of problematic pigmented lesions such as atypical Spitz nevi, there can be low interobserver agreement even among the experts in categorizing lesions as malignant versus nonmalignant (κ=0.30).³ The low concordance among expert dermatopathologists demonstrates that light microscopic features alone often are inadequate for diagnosis. Advanced studies, including immunohistochemical stains, can help to clarify the diagnosis. In the case of atypical Spitz tumors, the contribution of special stains to the final diagnosis is statistically similar to that of hematoxylin and eosin sections and age, suggesting that nothing alone is sufficiently reliable to establish a definitive diagnosis in every case.⁴ Although helpful, these studies are costly, and savings obtained by sending cases to the lowest bidder can evaporate quickly. Costs are higher when factoring in molecular studies, which can run upwards of $3000 per slide; the cost of litigation related to incorrect diagnoses; or the human costs of an incorrect diagnosis.

As a group, dermatopathologists are highly skilled in the interpretation of skin specimens, but challenging lesions are common in the routine practice of dermatopathology. A study of 1249 pigmented melanocytic lesions demonstrated substantial agreement among expert dermatopathologists for less problematic lesions, though agreement was greater for patients 40 years and older (κ=0.67) than for younger patients (κ=0.49). Agreement was lower for patients with atypical mole syndrome (κ=0.31).⁵ These discrepancies occur despite the fact that there is good interobserver reproducibility for grading of individual histological features such as asymmetry, circumscription, irregular confluent nests, single melanocytes predominating, absence of maturation, suprabasal melanocytes, symmetrical melanin, deep melanin, cytological atypia, mitoses, dermal lymphocytic infiltrate, and necrosis.⁶ These results indicate that accurate diagnoses cannot be reliably established simply by grading a list of histological features. Accurate diagnosis requires complex pattern recognition and integration of findings. Conflicting criteria often are present and an accurate interpretation requires considerable judgment as to which features are significant and which are not.

Separation of sebaceous adenoma, sebaceoma, and well-differentiated sebaceous carcinoma is another challenging area, and interobserver consensus can be as low as 11%,⁷ which suggests notable subjectivity in the criteria for diagnosis of nonmelanocytic tumors and emphasizes the importance of communication between the dermatopathologist and clinician when determining how to manage an ambiguous lesion. The interpretation of inflammatory skin diseases, alopecia, and lymphoid proliferations also can be problematic, and expert consultation often is required.

All dermatologists receive substantial training in dermatopathology, which puts them in an excellent position to interpret ambiguous findings in the context of the clinical presentation. Sometimes the dermatologist who has seen the clinical presentation can be in the best position to make the diagnosis. All clinicians must be wary of bias and an objective set of eyes often can be helpful. Communication is crucial to ensure appropriate care for each patient, and policies that restrict the choice of pathologist can be damaging.

As employers search for ways to reduce the cost of providing health care to their employees, there is a growing trend toward narrowed provider networks and exclusive laboratory contracts. In the case of clinical pathology, some of these choices make sense from the employer’s perspective. A complete blood cell count or comprehensive metabolic panel is done on a machine and the result is much the same regardless of the laboratory. So why not have all laboratory tests performed by the lowest bidder?

Laboratories vary in quality and anatomic pathology services are different from blood tests. Each slide must be interpreted by a physician and skill in the interpretation of skin specimens varies widely. Dermatopathology was one of the first subspecialties to be recognized within pathology, as it requires a high level of expertise. Clinicopathological correlation often is key to the accurate interpretation of a specimen. The stakes are high, and a delay in diagnosis of melanoma remains one of the most serious errors in medicine and one of the most common causes for litigation in dermatology.

The accurate interpretation of skin biopsy specimens becomes especially difficult when inadequate or misleading clinical information accompanies the specimen. A study of 589 biopsies submitted by primary care physicians and reported by general pathologists demonstrated a 6.5% error rate. False-negative errors were the most common, but false-positives also were observed.¹ A study of pigmented lesions referred to the University of California, San Francisco, demonstrated a discordance rate of 14.3%.² The degree of discordance would be expected to vary based on the range of diagnoses included in each study.

Board-certified dermatopathologists have varying areas of expertise and there is notable subjectivity in the interpretation of biopsy specimens. In the case of problematic pigmented lesions such as atypical Spitz nevi, there can be low interobserver agreement even among the experts in categorizing lesions as malignant versus nonmalignant (κ=0.30).³ The low concordance among expert dermatopathologists demonstrates that light microscopic features alone often are inadequate for diagnosis. Advanced studies, including immunohistochemical stains, can help to clarify the diagnosis. In the case of atypical Spitz tumors, the contribution of special stains to the final diagnosis is statistically similar to that of hematoxylin and eosin sections and age, suggesting that nothing alone is sufficiently reliable to establish a definitive diagnosis in every case.⁴ Although helpful, these studies are costly, and savings obtained by sending cases to the lowest bidder can evaporate quickly. Costs are higher when factoring in molecular studies, which can run upwards of $3000 per slide; the cost of litigation related to incorrect diagnoses; or the human costs of an incorrect diagnosis.

As a group, dermatopathologists are highly skilled in the interpretation of skin specimens, but challenging lesions are common in the routine practice of dermatopathology. A study of 1249 pigmented melanocytic lesions demonstrated substantial agreement among expert dermatopathologists for less problematic lesions, though agreement was greater for patients 40 years and older (κ=0.67) than for younger patients (κ=0.49). Agreement was lower for patients with atypical mole syndrome (κ=0.31).⁵ These discrepancies occur despite the fact that there is good interobserver reproducibility for grading of individual histological features such as asymmetry, circumscription, irregular confluent nests, single melanocytes predominating, absence of maturation, suprabasal melanocytes, symmetrical melanin, deep melanin, cytological atypia, mitoses, dermal lymphocytic infiltrate, and necrosis.⁶ These results indicate that accurate diagnoses cannot be reliably established simply by grading a list of histological features. Accurate diagnosis requires complex pattern recognition and integration of findings. Conflicting criteria often are present and an accurate interpretation requires considerable judgment as to which features are significant and which are not.

Separation of sebaceous adenoma, sebaceoma, and well-differentiated sebaceous carcinoma is another challenging area, and interobserver consensus can be as low as 11%,⁷ which suggests notable subjectivity in the criteria for diagnosis of nonmelanocytic tumors and emphasizes the importance of communication between the dermatopathologist and clinician when determining how to manage an ambiguous lesion. The interpretation of inflammatory skin diseases, alopecia, and lymphoid proliferations also can be problematic, and expert consultation often is required.

All dermatologists receive substantial training in dermatopathology, which puts them in an excellent position to interpret ambiguous findings in the context of the clinical presentation. Sometimes the dermatologist who has seen the clinical presentation can be in the best position to make the diagnosis. All clinicians must be wary of bias and an objective set of eyes often can be helpful. Communication is crucial to ensure appropriate care for each patient, and policies that restrict the choice of pathologist can be damaging.

As employers search for ways to reduce the cost of providing health care to their employees, there is a growing trend toward narrowed provider networks and exclusive laboratory contracts. In the case of clinical pathology, some of these choices make sense from the employer’s perspective. A complete blood cell count or comprehensive metabolic panel is done on a machine and the result is much the same regardless of the laboratory. So why not have all laboratory tests performed by the lowest bidder?

Laboratories vary in quality and anatomic pathology services are different from blood tests. Each slide must be interpreted by a physician and skill in the interpretation of skin specimens varies widely. Dermatopathology was one of the first subspecialties to be recognized within pathology, as it requires a high level of expertise. Clinicopathological correlation often is key to the accurate interpretation of a specimen. The stakes are high, and a delay in diagnosis of melanoma remains one of the most serious errors in medicine and one of the most common causes for litigation in dermatology.

The accurate interpretation of skin biopsy specimens becomes especially difficult when inadequate or misleading clinical information accompanies the specimen. A study of 589 biopsies submitted by primary care physicians and reported by general pathologists demonstrated a 6.5% error rate. False-negative errors were the most common, but false-positives also were observed.¹ A study of pigmented lesions referred to the University of California, San Francisco, demonstrated a discordance rate of 14.3%.² The degree of discordance would be expected to vary based on the range of diagnoses included in each study.

Board-certified dermatopathologists have varying areas of expertise and there is notable subjectivity in the interpretation of biopsy specimens. In the case of problematic pigmented lesions such as atypical Spitz nevi, there can be low interobserver agreement even among the experts in categorizing lesions as malignant versus nonmalignant (κ=0.30).³ The low concordance among expert dermatopathologists demonstrates that light microscopic features alone often are inadequate for diagnosis. Advanced studies, including immunohistochemical stains, can help to clarify the diagnosis. In the case of atypical Spitz tumors, the contribution of special stains to the final diagnosis is statistically similar to that of hematoxylin and eosin sections and age, suggesting that nothing alone is sufficiently reliable to establish a definitive diagnosis in every case.⁴ Although helpful, these studies are costly, and savings obtained by sending cases to the lowest bidder can evaporate quickly. Costs are higher when factoring in molecular studies, which can run upwards of $3000 per slide; the cost of litigation related to incorrect diagnoses; or the human costs of an incorrect diagnosis.

As a group, dermatopathologists are highly skilled in the interpretation of skin specimens, but challenging lesions are common in the routine practice of dermatopathology. A study of 1249 pigmented melanocytic lesions demonstrated substantial agreement among expert dermatopathologists for less problematic lesions, though agreement was greater for patients 40 years and older (κ=0.67) than for younger patients (κ=0.49). Agreement was lower for patients with atypical mole syndrome (κ=0.31).⁵ These discrepancies occur despite the fact that there is good interobserver reproducibility for grading of individual histological features such as asymmetry, circumscription, irregular confluent nests, single melanocytes predominating, absence of maturation, suprabasal melanocytes, symmetrical melanin, deep melanin, cytological atypia, mitoses, dermal lymphocytic infiltrate, and necrosis.⁶ These results indicate that accurate diagnoses cannot be reliably established simply by grading a list of histological features. Accurate diagnosis requires complex pattern recognition and integration of findings. Conflicting criteria often are present and an accurate interpretation requires considerable judgment as to which features are significant and which are not.

Separation of sebaceous adenoma, sebaceoma, and well-differentiated sebaceous carcinoma is another challenging area, and interobserver consensus can be as low as 11%,⁷ which suggests notable subjectivity in the criteria for diagnosis of nonmelanocytic tumors and emphasizes the importance of communication between the dermatopathologist and clinician when determining how to manage an ambiguous lesion. The interpretation of inflammatory skin diseases, alopecia, and lymphoid proliferations also can be problematic, and expert consultation often is required.

All dermatologists receive substantial training in dermatopathology, which puts them in an excellent position to interpret ambiguous findings in the context of the clinical presentation. Sometimes the dermatologist who has seen the clinical presentation can be in the best position to make the diagnosis. All clinicians must be wary of bias and an objective set of eyes often can be helpful. Communication is crucial to ensure appropriate care for each patient, and policies that restrict the choice of pathologist can be damaging.

Epidermal nevi can occur in isolation or in association with internal abnormalities. Epidermal nevus syndrome (ENS) is a heterogeneous group of neurocutaneous disorders characterized by mosaicism and epidermal nevi found in association with various systemic abnormalities.^1-4 There are many possible associated systemic findings, including abnormalities of the central nervous, musculoskeletal, renal, and hematologic systems. Epidermal nevi have been associated with internal malignancies. We present the case of a patient with epidermal nevi associated with papillary transitional cell bladder carcinoma. According to a PubMed search of articles indexed for MEDLINE using the search terms transitional cell bladder carcinoma and epidermal nevus, there have only been 4 other cases of transitional cell bladder carcinoma and ENS reported in the literature,^5-8 2 of which were reports of papillary transitional cell bladder carcinoma.^5,6

Case Report

A 29-year-old woman presented to our clinic with a rash that had been present since 3 years of age. The emergency department consulted dermatology for evaluation of what was believed to be contact dermatitis; however, upon questioning the patient, it was revealed that the rash was chronic and persistent.

The rash was nonpruritic and was located on the face, hands (Figure 1), chest, buttocks, thighs, legs, and back (Figure 2). Although asymptomatic, the appearance of the skin caused the patient some emotional distress. As a child she had been evaluated by a dermatologist and a biopsy was performed, but she did not recall the results or have any records. She had been prescribed an oral medication by the dermatologist, but treatment was terminated early due to nausea. The skin lesions did not improve with the short course of treatment.

Eighteen months prior to presentation to our clinic, the patient was discovered to have hematuria on routine examination by her primary care physician. At that time, the patient underwent a workup for hematuria and a mass was discovered in the bladder via cystoscopy. A diagnosis of low-grade papillary transitional cell bladder carcinoma was made, and she underwent a partial cystectomy. No radiation or chemotherapy was required. The remainder of her medical history was only remarkable for asthma, which was well controlled with albuterol. On examination, generalized, hyperpigmented, reticulated patches, macules, and hyperpigmented verrucous plaques were distributed along the Blaschko lines, sparing the face. No limb abnormalities or dental or nail abnormalities were noted. Examination of the axillary and cervical lymph nodes was unremarkable, and no neurological abnormalities were noted. A 3-mm punch biopsy of the mid upper back was performed. Histopathology revealed papillomatous, nonorganoid, nonepidermolytic hyperplasia of the epidermis with elongated rete ridges (Figure 3), which was diagnosed as a nonorganoid nonepidermolytic epidermal nevus.

Comment

Epidermal nevus syndrome is a group of disorders characterized by both local or systematized epidermal nevi and systemic findings. Solomon et al⁴ first coined the term epidermal nevus syndrome more than 40 years ago; however, since then there has been confusion about how to define ENS. Epidermal nevus syndrome has been considered an umbrella term that includes more specific syndromes involving epidermal nevi, such as Proteus syndrome and Schimmelpenning syndrome; conversely, it also has been considered a term for those who do not meet the criteria for more specific syndromes.^1,9 Happle¹ discussed that the genetic variations found in ENS warrant recognition. Simply put, ENS is a heterogeneous group of syndromes that are similar in that they involve epidermal nevi and internal abnormalities but are genetically distinct. The list of definitive ENSs, as suggested by Happle¹ and others, will likely continue to grow.^3,5

The exact pathomechanism of ENS is unknown, but the clinical presentation most likely represents a lethal disorder mitigated by mosaicism.^2,9 Gene defects vary depending on the specific ENS. For instance, the phosphatase and tensin homolog gene, PTEN, mutations have been associated with type 2 segmental Cowden disease. Fibroblast growth factor receptor 3, FGFR3, mutations have been linked to Garcia-Hafner-Happle syndrome.³FGFR3 mutations have been found in nonepidermolytic epidermal nevi, and some suggest that the majority of epidermal nevi exhibit mutations in FGFR3.^5,10,11 On the other hand, other gene defects have not been elucidated, such as in Schimmelpenning syndrome.³

Clinically, ENS may involve nonepidermolytic verrucous nevi, sebaceous nevi, organoid nevi, linear Cowden nevi, and woolly hair nevi. Lesions may be flesh-colored, pink, yellow, or hyperpigmented plaques in a blaschkoid distribution and may be localized or systematized. Nevi typically are present at birth or develop within the first year of life.^9,12,13 Other cutaneous findings may be noted apart from epidermal nevi, including melanocytic nevi, aplasia cutis congenita, and hemangiomas.^13,14

Extracutaneous findings include central nervous system, skeletal, ocular, cardiac, and genitourinary defects, which are often observed in these patients.^3,9,13,14 Central nervous system findings are seen in 50% to 70% of cases, with seizures and mental retardation among the most common.^13-15 Genitourinary abnormalities associated with epidermal nevi, including horseshoe kidney, cystic kidney, duplicated collecting system, testicular and paratesticular tumors, and hypospadias have been documented in the literature.¹⁶ Our patient had a history of papillary transitional cell bladder carcinoma, which is rare for a patient younger than 30 years. The overall median age of diagnosis of bladder cancer is 65 years, and it is more common in men than in women.¹⁷ Transitional cell carcinomas account for approximately 90% of all bladder cancers in the United States. Other common types of bladder cancer include squamous cell carcinoma, adenocarcinoma, and rhabdomyosarcoma.¹⁶ Typically, transitional cell carcinoma is associated with smoking, exposure to aniline dyes, cyclophosphamide, and living in industrialized areas.^16,17 Individuals who work with textiles, dyes, leather, tires, rubber, and/or petroleum; painters; truck drivers; drill press operators; and hairdressers are at an increased risk for development of bladder cancer.¹⁶

Interestingly, it has been shown in some studies that papillary transitional cell bladder carcinoma frequently is associated with FGFR3 mutations, which may be the missing link in the rare finding of papillary transitional cell bladder carcinoma and epidermal nevi.^5,18,19 In addition, PTEN mutations also have been identified in low-grade papillary transitional cell carcinomas of the bladder, another gene linked to an ENS with type 2 segmental Cowden disease.^3,20

Histopathologically, epidermal nevi have 10 different descriptions. Our patient had a nonorganoid nonepidermolytic epidermal nevus characterized by hyperkeratosis, acanthosis, papillomatosis, and elongated rete ridges. Focal acantholysis and epidermolytic hyperkeratosis also is seen in some epidermal nevi but was not seen in this case.^9,21

Simple epidermal nevi occur in approximately 1 in 1000 newborns; however, when a child presents with multiple or systematized epidermal nevi, investigation should be undertaken for other possible associations.^13,14 Of note, there have been several cases of squamous cell, verrucous, basal cell, and adnexal carcinomas arising in linear epidermal nevi.^22-24

Epidermal nevi can be difficult to treat. Some patients are troubled by the appearance of these nevi, especially those with systematized disease. Unfortunately, for patients with multiple nevi or systematized disease, there are no consistently effective treatment options; however, there are case reports^25,26 in the literature citing improvement or cure of epidermal nevi with full-thickness excision, continuous and pulsed CO₂ laser, pulsed dye laser, and erbium-doped YAG laser.²⁵ Other therapies that have been purported to help improve epidermal nevi are topical and oral retinoids, corticosteroids, topical 5-fluorouracil, anthralin, and podophyllin.²⁶

Conclusion

Transitional cell bladder carcinoma is rare in patients in the third decade of life and younger. Given the age of our patient and her concomitant lack of risk factors, such as older age, history of smoking, and exposure to certain chemicals (eg, aniline dyes) and medications (eg, cyclophosphamide), it is more likely that the finding of papillary transitional cell bladder carcinoma and ENS are related. A clear genetic link between ENS and transitional cell papillary bladder carcinoma has yet to be elucidated, but the FGFR3 gene is promising.

Epidermal nevi can occur in isolation or in association with internal abnormalities. Epidermal nevus syndrome (ENS) is a heterogeneous group of neurocutaneous disorders characterized by mosaicism and epidermal nevi found in association with various systemic abnormalities.^1-4 There are many possible associated systemic findings, including abnormalities of the central nervous, musculoskeletal, renal, and hematologic systems. Epidermal nevi have been associated with internal malignancies. We present the case of a patient with epidermal nevi associated with papillary transitional cell bladder carcinoma. According to a PubMed search of articles indexed for MEDLINE using the search terms transitional cell bladder carcinoma and epidermal nevus, there have only been 4 other cases of transitional cell bladder carcinoma and ENS reported in the literature,^5-8 2 of which were reports of papillary transitional cell bladder carcinoma.^5,6

Case Report

A 29-year-old woman presented to our clinic with a rash that had been present since 3 years of age. The emergency department consulted dermatology for evaluation of what was believed to be contact dermatitis; however, upon questioning the patient, it was revealed that the rash was chronic and persistent.

The rash was nonpruritic and was located on the face, hands (Figure 1), chest, buttocks, thighs, legs, and back (Figure 2). Although asymptomatic, the appearance of the skin caused the patient some emotional distress. As a child she had been evaluated by a dermatologist and a biopsy was performed, but she did not recall the results or have any records. She had been prescribed an oral medication by the dermatologist, but treatment was terminated early due to nausea. The skin lesions did not improve with the short course of treatment.

Eighteen months prior to presentation to our clinic, the patient was discovered to have hematuria on routine examination by her primary care physician. At that time, the patient underwent a workup for hematuria and a mass was discovered in the bladder via cystoscopy. A diagnosis of low-grade papillary transitional cell bladder carcinoma was made, and she underwent a partial cystectomy. No radiation or chemotherapy was required. The remainder of her medical history was only remarkable for asthma, which was well controlled with albuterol. On examination, generalized, hyperpigmented, reticulated patches, macules, and hyperpigmented verrucous plaques were distributed along the Blaschko lines, sparing the face. No limb abnormalities or dental or nail abnormalities were noted. Examination of the axillary and cervical lymph nodes was unremarkable, and no neurological abnormalities were noted. A 3-mm punch biopsy of the mid upper back was performed. Histopathology revealed papillomatous, nonorganoid, nonepidermolytic hyperplasia of the epidermis with elongated rete ridges (Figure 3), which was diagnosed as a nonorganoid nonepidermolytic epidermal nevus.

Comment

Epidermal nevus syndrome is a group of disorders characterized by both local or systematized epidermal nevi and systemic findings. Solomon et al⁴ first coined the term epidermal nevus syndrome more than 40 years ago; however, since then there has been confusion about how to define ENS. Epidermal nevus syndrome has been considered an umbrella term that includes more specific syndromes involving epidermal nevi, such as Proteus syndrome and Schimmelpenning syndrome; conversely, it also has been considered a term for those who do not meet the criteria for more specific syndromes.^1,9 Happle¹ discussed that the genetic variations found in ENS warrant recognition. Simply put, ENS is a heterogeneous group of syndromes that are similar in that they involve epidermal nevi and internal abnormalities but are genetically distinct. The list of definitive ENSs, as suggested by Happle¹ and others, will likely continue to grow.^3,5

The exact pathomechanism of ENS is unknown, but the clinical presentation most likely represents a lethal disorder mitigated by mosaicism.^2,9 Gene defects vary depending on the specific ENS. For instance, the phosphatase and tensin homolog gene, PTEN, mutations have been associated with type 2 segmental Cowden disease. Fibroblast growth factor receptor 3, FGFR3, mutations have been linked to Garcia-Hafner-Happle syndrome.³FGFR3 mutations have been found in nonepidermolytic epidermal nevi, and some suggest that the majority of epidermal nevi exhibit mutations in FGFR3.^5,10,11 On the other hand, other gene defects have not been elucidated, such as in Schimmelpenning syndrome.³

Clinically, ENS may involve nonepidermolytic verrucous nevi, sebaceous nevi, organoid nevi, linear Cowden nevi, and woolly hair nevi. Lesions may be flesh-colored, pink, yellow, or hyperpigmented plaques in a blaschkoid distribution and may be localized or systematized. Nevi typically are present at birth or develop within the first year of life.^9,12,13 Other cutaneous findings may be noted apart from epidermal nevi, including melanocytic nevi, aplasia cutis congenita, and hemangiomas.^13,14

Extracutaneous findings include central nervous system, skeletal, ocular, cardiac, and genitourinary defects, which are often observed in these patients.^3,9,13,14 Central nervous system findings are seen in 50% to 70% of cases, with seizures and mental retardation among the most common.^13-15 Genitourinary abnormalities associated with epidermal nevi, including horseshoe kidney, cystic kidney, duplicated collecting system, testicular and paratesticular tumors, and hypospadias have been documented in the literature.¹⁶ Our patient had a history of papillary transitional cell bladder carcinoma, which is rare for a patient younger than 30 years. The overall median age of diagnosis of bladder cancer is 65 years, and it is more common in men than in women.¹⁷ Transitional cell carcinomas account for approximately 90% of all bladder cancers in the United States. Other common types of bladder cancer include squamous cell carcinoma, adenocarcinoma, and rhabdomyosarcoma.¹⁶ Typically, transitional cell carcinoma is associated with smoking, exposure to aniline dyes, cyclophosphamide, and living in industrialized areas.^16,17 Individuals who work with textiles, dyes, leather, tires, rubber, and/or petroleum; painters; truck drivers; drill press operators; and hairdressers are at an increased risk for development of bladder cancer.¹⁶

Interestingly, it has been shown in some studies that papillary transitional cell bladder carcinoma frequently is associated with FGFR3 mutations, which may be the missing link in the rare finding of papillary transitional cell bladder carcinoma and epidermal nevi.^5,18,19 In addition, PTEN mutations also have been identified in low-grade papillary transitional cell carcinomas of the bladder, another gene linked to an ENS with type 2 segmental Cowden disease.^3,20

Histopathologically, epidermal nevi have 10 different descriptions. Our patient had a nonorganoid nonepidermolytic epidermal nevus characterized by hyperkeratosis, acanthosis, papillomatosis, and elongated rete ridges. Focal acantholysis and epidermolytic hyperkeratosis also is seen in some epidermal nevi but was not seen in this case.^9,21

Simple epidermal nevi occur in approximately 1 in 1000 newborns; however, when a child presents with multiple or systematized epidermal nevi, investigation should be undertaken for other possible associations.^13,14 Of note, there have been several cases of squamous cell, verrucous, basal cell, and adnexal carcinomas arising in linear epidermal nevi.^22-24

Epidermal nevi can be difficult to treat. Some patients are troubled by the appearance of these nevi, especially those with systematized disease. Unfortunately, for patients with multiple nevi or systematized disease, there are no consistently effective treatment options; however, there are case reports^25,26 in the literature citing improvement or cure of epidermal nevi with full-thickness excision, continuous and pulsed CO₂ laser, pulsed dye laser, and erbium-doped YAG laser.²⁵ Other therapies that have been purported to help improve epidermal nevi are topical and oral retinoids, corticosteroids, topical 5-fluorouracil, anthralin, and podophyllin.²⁶

Conclusion

Transitional cell bladder carcinoma is rare in patients in the third decade of life and younger. Given the age of our patient and her concomitant lack of risk factors, such as older age, history of smoking, and exposure to certain chemicals (eg, aniline dyes) and medications (eg, cyclophosphamide), it is more likely that the finding of papillary transitional cell bladder carcinoma and ENS are related. A clear genetic link between ENS and transitional cell papillary bladder carcinoma has yet to be elucidated, but the FGFR3 gene is promising.

Epidermal nevi can occur in isolation or in association with internal abnormalities. Epidermal nevus syndrome (ENS) is a heterogeneous group of neurocutaneous disorders characterized by mosaicism and epidermal nevi found in association with various systemic abnormalities.^1-4 There are many possible associated systemic findings, including abnormalities of the central nervous, musculoskeletal, renal, and hematologic systems. Epidermal nevi have been associated with internal malignancies. We present the case of a patient with epidermal nevi associated with papillary transitional cell bladder carcinoma. According to a PubMed search of articles indexed for MEDLINE using the search terms transitional cell bladder carcinoma and epidermal nevus, there have only been 4 other cases of transitional cell bladder carcinoma and ENS reported in the literature,^5-8 2 of which were reports of papillary transitional cell bladder carcinoma.^5,6

Case Report

A 29-year-old woman presented to our clinic with a rash that had been present since 3 years of age. The emergency department consulted dermatology for evaluation of what was believed to be contact dermatitis; however, upon questioning the patient, it was revealed that the rash was chronic and persistent.

The rash was nonpruritic and was located on the face, hands (Figure 1), chest, buttocks, thighs, legs, and back (Figure 2). Although asymptomatic, the appearance of the skin caused the patient some emotional distress. As a child she had been evaluated by a dermatologist and a biopsy was performed, but she did not recall the results or have any records. She had been prescribed an oral medication by the dermatologist, but treatment was terminated early due to nausea. The skin lesions did not improve with the short course of treatment.

Eighteen months prior to presentation to our clinic, the patient was discovered to have hematuria on routine examination by her primary care physician. At that time, the patient underwent a workup for hematuria and a mass was discovered in the bladder via cystoscopy. A diagnosis of low-grade papillary transitional cell bladder carcinoma was made, and she underwent a partial cystectomy. No radiation or chemotherapy was required. The remainder of her medical history was only remarkable for asthma, which was well controlled with albuterol. On examination, generalized, hyperpigmented, reticulated patches, macules, and hyperpigmented verrucous plaques were distributed along the Blaschko lines, sparing the face. No limb abnormalities or dental or nail abnormalities were noted. Examination of the axillary and cervical lymph nodes was unremarkable, and no neurological abnormalities were noted. A 3-mm punch biopsy of the mid upper back was performed. Histopathology revealed papillomatous, nonorganoid, nonepidermolytic hyperplasia of the epidermis with elongated rete ridges (Figure 3), which was diagnosed as a nonorganoid nonepidermolytic epidermal nevus.

Comment

Epidermal nevus syndrome is a group of disorders characterized by both local or systematized epidermal nevi and systemic findings. Solomon et al⁴ first coined the term epidermal nevus syndrome more than 40 years ago; however, since then there has been confusion about how to define ENS. Epidermal nevus syndrome has been considered an umbrella term that includes more specific syndromes involving epidermal nevi, such as Proteus syndrome and Schimmelpenning syndrome; conversely, it also has been considered a term for those who do not meet the criteria for more specific syndromes.^1,9 Happle¹ discussed that the genetic variations found in ENS warrant recognition. Simply put, ENS is a heterogeneous group of syndromes that are similar in that they involve epidermal nevi and internal abnormalities but are genetically distinct. The list of definitive ENSs, as suggested by Happle¹ and others, will likely continue to grow.^3,5

The exact pathomechanism of ENS is unknown, but the clinical presentation most likely represents a lethal disorder mitigated by mosaicism.^2,9 Gene defects vary depending on the specific ENS. For instance, the phosphatase and tensin homolog gene, PTEN, mutations have been associated with type 2 segmental Cowden disease. Fibroblast growth factor receptor 3, FGFR3, mutations have been linked to Garcia-Hafner-Happle syndrome.³FGFR3 mutations have been found in nonepidermolytic epidermal nevi, and some suggest that the majority of epidermal nevi exhibit mutations in FGFR3.^5,10,11 On the other hand, other gene defects have not been elucidated, such as in Schimmelpenning syndrome.³

Clinically, ENS may involve nonepidermolytic verrucous nevi, sebaceous nevi, organoid nevi, linear Cowden nevi, and woolly hair nevi. Lesions may be flesh-colored, pink, yellow, or hyperpigmented plaques in a blaschkoid distribution and may be localized or systematized. Nevi typically are present at birth or develop within the first year of life.^9,12,13 Other cutaneous findings may be noted apart from epidermal nevi, including melanocytic nevi, aplasia cutis congenita, and hemangiomas.^13,14

Extracutaneous findings include central nervous system, skeletal, ocular, cardiac, and genitourinary defects, which are often observed in these patients.^3,9,13,14 Central nervous system findings are seen in 50% to 70% of cases, with seizures and mental retardation among the most common.^13-15 Genitourinary abnormalities associated with epidermal nevi, including horseshoe kidney, cystic kidney, duplicated collecting system, testicular and paratesticular tumors, and hypospadias have been documented in the literature.¹⁶ Our patient had a history of papillary transitional cell bladder carcinoma, which is rare for a patient younger than 30 years. The overall median age of diagnosis of bladder cancer is 65 years, and it is more common in men than in women.¹⁷ Transitional cell carcinomas account for approximately 90% of all bladder cancers in the United States. Other common types of bladder cancer include squamous cell carcinoma, adenocarcinoma, and rhabdomyosarcoma.¹⁶ Typically, transitional cell carcinoma is associated with smoking, exposure to aniline dyes, cyclophosphamide, and living in industrialized areas.^16,17 Individuals who work with textiles, dyes, leather, tires, rubber, and/or petroleum; painters; truck drivers; drill press operators; and hairdressers are at an increased risk for development of bladder cancer.¹⁶

Interestingly, it has been shown in some studies that papillary transitional cell bladder carcinoma frequently is associated with FGFR3 mutations, which may be the missing link in the rare finding of papillary transitional cell bladder carcinoma and epidermal nevi.^5,18,19 In addition, PTEN mutations also have been identified in low-grade papillary transitional cell carcinomas of the bladder, another gene linked to an ENS with type 2 segmental Cowden disease.^3,20

Histopathologically, epidermal nevi have 10 different descriptions. Our patient had a nonorganoid nonepidermolytic epidermal nevus characterized by hyperkeratosis, acanthosis, papillomatosis, and elongated rete ridges. Focal acantholysis and epidermolytic hyperkeratosis also is seen in some epidermal nevi but was not seen in this case.^9,21

Simple epidermal nevi occur in approximately 1 in 1000 newborns; however, when a child presents with multiple or systematized epidermal nevi, investigation should be undertaken for other possible associations.^13,14 Of note, there have been several cases of squamous cell, verrucous, basal cell, and adnexal carcinomas arising in linear epidermal nevi.^22-24

Epidermal nevi can be difficult to treat. Some patients are troubled by the appearance of these nevi, especially those with systematized disease. Unfortunately, for patients with multiple nevi or systematized disease, there are no consistently effective treatment options; however, there are case reports^25,26 in the literature citing improvement or cure of epidermal nevi with full-thickness excision, continuous and pulsed CO₂ laser, pulsed dye laser, and erbium-doped YAG laser.²⁵ Other therapies that have been purported to help improve epidermal nevi are topical and oral retinoids, corticosteroids, topical 5-fluorouracil, anthralin, and podophyllin.²⁶

Conclusion

Transitional cell bladder carcinoma is rare in patients in the third decade of life and younger. Given the age of our patient and her concomitant lack of risk factors, such as older age, history of smoking, and exposure to certain chemicals (eg, aniline dyes) and medications (eg, cyclophosphamide), it is more likely that the finding of papillary transitional cell bladder carcinoma and ENS are related. A clear genetic link between ENS and transitional cell papillary bladder carcinoma has yet to be elucidated, but the FGFR3 gene is promising.

Differentiation between a primary adnexal carcinoma and a metastatic carcinoma to the skin is a challenging yet critical task for dermatologists and pathologists. Carcinomas that have metastasized to the skin are a sign of widespread systemic involvement and poor prognosis, while primary adnexal carcinomas tend to progress with an indolent clinical course. Although many patients with cutaneous metastases from an internal primary neoplasm can expect a median survival of no more than 12 months,¹ patients with primary adnexal carcinomas are reported to have a 5-year survival rate of 95.5% for localized disease and 85% with spread to regional lymph nodes.² We report a case of multiple cutaneous neoplasms of unknown primary origin in a 71-year-old man and describe our approach to identification of the possible primary site as well as management of the disease.  

Case Report

A 71-year-old man initially presented to his primary physician for evaluation of a mass on the left side of the neck of 3 months' duration. On physical examination, a firm 2.5×3.0-cm nodule was noted at the anterior border of the trapezius muscle. Palpation of the thyroid revealed an additional right-sided nodule. The submandibular and parotid glands were unremarkable to palpation. The patient was referred to general surgery for biopsy, which revealed an infiltrating, moderately differentiated adenocarcinoma with extensive lymphatic permeation. Immunohistochemical staining for cytokeratin (CK) 7 was positive, while CK20 and thyroid transcription factor 1 were negative. A positron emission tomography/computed tomography (CT) fusion scan demonstrated 3 areas of enhanced uptake: one in the right side of the thyroid, a second corresponding to the mass on the left side of the neck at the level of the trapezius muscle, and a third in the left masseter muscle. Surgical excision with negative margins with possible chemotherapy was recommended; however, the patient declined treatment and was lost to follow-up until 2 years later when he presented to his primary physician with an additional lesion on his scalp.

Four years after the biopsy, the patient presented to the dermatology department with additional tumor nodules including a 4-cm, annular, indurated, focally eroded plaque on the left side of the lateral neck (Figure 1); 3 separate 1-cm nodules on the right side of the lateral neck; and an ulcerated, crusted, 10×8-cm plaque on the posterior aspect of the scalp. Despite the extensive lesions, the patient remained in good health and reported no recent weight loss or signs or symptoms of systemic involvement. The posterior scalp lesion, which developed 2 years after the initial appearance of the mass on the neck and was thought to represent a possible metastasis of the tumor, was biopsied and showed diffuse infiltration of the dermis by poorly differentiated tumor cells with vacuolated cytoplasm arranged in nests and cords and sometimes in a single-file arrangement (Figure 2). A CT scan demonstrated pretracheal lymphadenopathy as well as small intraparenchymal and subpleural pulmonary nodules throughout both lung fields.

Another scalp biopsy was taken. Tumor cells were negative on mucicarmine staining. Additional immunohistochemical staining, including a periodic acid-Schiff stain with diastase digestion for epithelial mucin revealed minimal luminal positivity. Immunostaining was positive for CK7, carcinoembryonic antigen, CD15, estrogen receptor, progesterone receptor, gross cystic disease fluid protein 15 (GCDFP-15), and mammaglobin, and negative for CK20, podoplanin, thyroid transcription factor 1, S-100 protein, p63, and prostate specific antigen. ERBB2 (formerly HER2/neu) staining was negative according to fluorescence in situ hybridization analysis. Tumor cells showed a Ki-67 nuclear proliferation index of greater than 50%, indicating progression to aggressive carcinoma. 

Based on the histological and immunochemical studies, the differential diagnosis included primary cutaneous apocrine carcinoma versus breast carcinoma; however, the prolonged clinical progression of these lesions favored a primary cutaneous adnexal tumor over a metastatic adenocarcinoma. Nevertheless, despite the initially indolent growth of the lesions over the first 5 years, the Ki-67 proliferation index and presence of widespread metastases on the posterior scalp indicated progression to an aggressive carcinoma. Chemotherapy was recommended as the treatment of choice. At his most recent follow-up visit 4 months later, the patient chose to begin treatment with tamoxifen and refused other treatment options.

Comment

The distinction between primary adnexal and metastatic adenocarcinomas of the skin is challenging both clinically and histologically. Some pathologists have argued that metastatic breast carcinomas and primary cutaneous apocrine carcinomas are essentially indistinguishable.³ Patients with cutaneous metastases, which occur in approximately 5.3% of all malignancies,⁴ typically can expect survival of no more than 12 months from the time of detection.¹ In contrast, primary apocrine carcinomas of the skin, though much less common, carry a remarkably better prognosis, with 5-year relative survival rates of 95.5% and 85.5% reported for patients with localized disease and spread to regional lymph nodes, respectively.²

Fewer than 100 cases of primary cutaneous adnexal (apocrine) carcinomas have been reported overall, with the earliest known report dating back to 1944.⁵ According to the literature, primary apocrine carcinomas were diagnosed at a median age of 66 years and were slightly more common in females than males.^2,6 Apocrine carcinomas were seen most frequently on the head, neck, and trunk,² generally presenting in the form of asymptomatic nodules or plaques of 2 to 3 cm in size, with gradual progression occurring over months to years.⁶ Approximately 40% of patients have been reported with positive regional lymph nodes at diagnosis. Treatment of apocrine carcinoma typically has involved local excision with clear margins with or without lymph node dissection. Chemotherapy and radiation therapy have shown no proven benefit.⁷

Currently, there is no standardized approach to evaluating patients with possible cutaneous metastasis versus primary cutaneous adnexal carcinomas. Imaging studies such as mammography and abdominal CT typically reveal an internal primary cancer in one-third of patients. However, additional studies such as gastrointestinal radiography, chest and pelvic CT, barium enema, and intravenous pyelogram have shown to be of limited value.⁸ Although specificity and sensitivity of immunohistochemistry is limited, a number of immunomarkers, including CK7 and CK20, are routinely studied to narrow the differential diagnosis of a cutaneous neoplasm of unclear origin. Urothelial, gastric, colorectal, and pancreatic carcinomas generally are positive for CK20; CK7-positive adenocarcinomas include salivary, non-small cell lung, breast, ovarian, pancreatic, endometrial, and transitional cell adenocarcinomas. Carcinomas negative for both CK7 and CK20 include colorectal, hepatocellular, renal cell, prostate, and squamous cell carcinoma of the lung. 

The presence of positive staining for estrogen and progesterone receptors as well as GCDFP-15 and mammaglobin raised the possibility of primary breast adenocarcinoma in our patient, but given that these markers can be positive in primary cutaneous adnexal tumors, immunohistochemistry results were not able to provide a definitive primary site. The overall staining pattern was nearly identical to 26 cases of primary cutaneous cribriform apocrine carcinoma, which was found to be positive for CK7 and carcinoembryonic antigen, and negative for CK20 and S-100. The only difference was in GCDFP-15 staining, which was positive in our case and negative in the cases of cribriform apocrine carcinoma.⁹ Histologic features favoring a primary apocrine origin include normal apocrine glands in the vicinity, glandular structures with decapitation secretion high in the dermis, and intracytoplasmic iron granules.¹⁰ Additionally, positive estrogen receptor staining appears to be much more common in apocrine carcinomas (5/10) than in eccrine carcinomas (1/7).¹¹

A number of other markers have been investigated for possible diagnostic utility for distinction between primary adnexal carcinomas and metastatic adenocarcinomas. The nuclear transcription factor p63, which plays a role in keratinocyte differentiation, is preferentially expressed in a number of primary adnexal carcinomas and is purported to be the most sensitive marker overall, with a sensitivity of 78% to 91%.^12-14 However, p63 has shown incomplete specificity for primary adnexal neoplasms, having been reported as positive in 11% to 22% of adenocarcinomas metastatic to skin.^15-18 Nestin and CK15, which are expressed in hair follicle progenitor cells, also are potential specific markers for some primary adnexal lesions, specifically eccrine carcinoma, porocarcinoma, hidradenocarcinoma, and microcystic adnexal carcinoma; however, in one report, none of the apocrine carcinomas were positive for p63, cytokeratin 15, or D2-40.¹⁹ Thus, while markers for some primary adnexal neoplasms are emerging, specific tests at the immunohistochemical level for the apocrine carcinoma subgroup are still lacking.

Conclusion

In summary, a conclusive distinction between primary cutaneous apocrine carcinoma and metastatic adenocarcinoma to the skin remains challenging. Although new markers provide more specificity and sensitivity for neoplasms of eccrine origin, these markers do not appear to differentiate between primary apocrine carcinoma and metastatic breast carcinoma. In this case, as in other recent reports, diagnosis remained dependent on the clinical course of the patient. Although considerable progress has been made regarding immunohistochemical analysis of these cases, additional markers, especially ones more specific for primary skin cancers with apocrine differentiation, are still needed.

Differentiation between a primary adnexal carcinoma and a metastatic carcinoma to the skin is a challenging yet critical task for dermatologists and pathologists. Carcinomas that have metastasized to the skin are a sign of widespread systemic involvement and poor prognosis, while primary adnexal carcinomas tend to progress with an indolent clinical course. Although many patients with cutaneous metastases from an internal primary neoplasm can expect a median survival of no more than 12 months,¹ patients with primary adnexal carcinomas are reported to have a 5-year survival rate of 95.5% for localized disease and 85% with spread to regional lymph nodes.² We report a case of multiple cutaneous neoplasms of unknown primary origin in a 71-year-old man and describe our approach to identification of the possible primary site as well as management of the disease.  

Case Report

A 71-year-old man initially presented to his primary physician for evaluation of a mass on the left side of the neck of 3 months' duration. On physical examination, a firm 2.5×3.0-cm nodule was noted at the anterior border of the trapezius muscle. Palpation of the thyroid revealed an additional right-sided nodule. The submandibular and parotid glands were unremarkable to palpation. The patient was referred to general surgery for biopsy, which revealed an infiltrating, moderately differentiated adenocarcinoma with extensive lymphatic permeation. Immunohistochemical staining for cytokeratin (CK) 7 was positive, while CK20 and thyroid transcription factor 1 were negative. A positron emission tomography/computed tomography (CT) fusion scan demonstrated 3 areas of enhanced uptake: one in the right side of the thyroid, a second corresponding to the mass on the left side of the neck at the level of the trapezius muscle, and a third in the left masseter muscle. Surgical excision with negative margins with possible chemotherapy was recommended; however, the patient declined treatment and was lost to follow-up until 2 years later when he presented to his primary physician with an additional lesion on his scalp.

Four years after the biopsy, the patient presented to the dermatology department with additional tumor nodules including a 4-cm, annular, indurated, focally eroded plaque on the left side of the lateral neck (Figure 1); 3 separate 1-cm nodules on the right side of the lateral neck; and an ulcerated, crusted, 10×8-cm plaque on the posterior aspect of the scalp. Despite the extensive lesions, the patient remained in good health and reported no recent weight loss or signs or symptoms of systemic involvement. The posterior scalp lesion, which developed 2 years after the initial appearance of the mass on the neck and was thought to represent a possible metastasis of the tumor, was biopsied and showed diffuse infiltration of the dermis by poorly differentiated tumor cells with vacuolated cytoplasm arranged in nests and cords and sometimes in a single-file arrangement (Figure 2). A CT scan demonstrated pretracheal lymphadenopathy as well as small intraparenchymal and subpleural pulmonary nodules throughout both lung fields.

Another scalp biopsy was taken. Tumor cells were negative on mucicarmine staining. Additional immunohistochemical staining, including a periodic acid-Schiff stain with diastase digestion for epithelial mucin revealed minimal luminal positivity. Immunostaining was positive for CK7, carcinoembryonic antigen, CD15, estrogen receptor, progesterone receptor, gross cystic disease fluid protein 15 (GCDFP-15), and mammaglobin, and negative for CK20, podoplanin, thyroid transcription factor 1, S-100 protein, p63, and prostate specific antigen. ERBB2 (formerly HER2/neu) staining was negative according to fluorescence in situ hybridization analysis. Tumor cells showed a Ki-67 nuclear proliferation index of greater than 50%, indicating progression to aggressive carcinoma. 

Based on the histological and immunochemical studies, the differential diagnosis included primary cutaneous apocrine carcinoma versus breast carcinoma; however, the prolonged clinical progression of these lesions favored a primary cutaneous adnexal tumor over a metastatic adenocarcinoma. Nevertheless, despite the initially indolent growth of the lesions over the first 5 years, the Ki-67 proliferation index and presence of widespread metastases on the posterior scalp indicated progression to an aggressive carcinoma. Chemotherapy was recommended as the treatment of choice. At his most recent follow-up visit 4 months later, the patient chose to begin treatment with tamoxifen and refused other treatment options.

Comment

The distinction between primary adnexal and metastatic adenocarcinomas of the skin is challenging both clinically and histologically. Some pathologists have argued that metastatic breast carcinomas and primary cutaneous apocrine carcinomas are essentially indistinguishable.³ Patients with cutaneous metastases, which occur in approximately 5.3% of all malignancies,⁴ typically can expect survival of no more than 12 months from the time of detection.¹ In contrast, primary apocrine carcinomas of the skin, though much less common, carry a remarkably better prognosis, with 5-year relative survival rates of 95.5% and 85.5% reported for patients with localized disease and spread to regional lymph nodes, respectively.²

Fewer than 100 cases of primary cutaneous adnexal (apocrine) carcinomas have been reported overall, with the earliest known report dating back to 1944.⁵ According to the literature, primary apocrine carcinomas were diagnosed at a median age of 66 years and were slightly more common in females than males.^2,6 Apocrine carcinomas were seen most frequently on the head, neck, and trunk,² generally presenting in the form of asymptomatic nodules or plaques of 2 to 3 cm in size, with gradual progression occurring over months to years.⁶ Approximately 40% of patients have been reported with positive regional lymph nodes at diagnosis. Treatment of apocrine carcinoma typically has involved local excision with clear margins with or without lymph node dissection. Chemotherapy and radiation therapy have shown no proven benefit.⁷

Currently, there is no standardized approach to evaluating patients with possible cutaneous metastasis versus primary cutaneous adnexal carcinomas. Imaging studies such as mammography and abdominal CT typically reveal an internal primary cancer in one-third of patients. However, additional studies such as gastrointestinal radiography, chest and pelvic CT, barium enema, and intravenous pyelogram have shown to be of limited value.⁸ Although specificity and sensitivity of immunohistochemistry is limited, a number of immunomarkers, including CK7 and CK20, are routinely studied to narrow the differential diagnosis of a cutaneous neoplasm of unclear origin. Urothelial, gastric, colorectal, and pancreatic carcinomas generally are positive for CK20; CK7-positive adenocarcinomas include salivary, non-small cell lung, breast, ovarian, pancreatic, endometrial, and transitional cell adenocarcinomas. Carcinomas negative for both CK7 and CK20 include colorectal, hepatocellular, renal cell, prostate, and squamous cell carcinoma of the lung. 

The presence of positive staining for estrogen and progesterone receptors as well as GCDFP-15 and mammaglobin raised the possibility of primary breast adenocarcinoma in our patient, but given that these markers can be positive in primary cutaneous adnexal tumors, immunohistochemistry results were not able to provide a definitive primary site. The overall staining pattern was nearly identical to 26 cases of primary cutaneous cribriform apocrine carcinoma, which was found to be positive for CK7 and carcinoembryonic antigen, and negative for CK20 and S-100. The only difference was in GCDFP-15 staining, which was positive in our case and negative in the cases of cribriform apocrine carcinoma.⁹ Histologic features favoring a primary apocrine origin include normal apocrine glands in the vicinity, glandular structures with decapitation secretion high in the dermis, and intracytoplasmic iron granules.¹⁰ Additionally, positive estrogen receptor staining appears to be much more common in apocrine carcinomas (5/10) than in eccrine carcinomas (1/7).¹¹

A number of other markers have been investigated for possible diagnostic utility for distinction between primary adnexal carcinomas and metastatic adenocarcinomas. The nuclear transcription factor p63, which plays a role in keratinocyte differentiation, is preferentially expressed in a number of primary adnexal carcinomas and is purported to be the most sensitive marker overall, with a sensitivity of 78% to 91%.^12-14 However, p63 has shown incomplete specificity for primary adnexal neoplasms, having been reported as positive in 11% to 22% of adenocarcinomas metastatic to skin.^15-18 Nestin and CK15, which are expressed in hair follicle progenitor cells, also are potential specific markers for some primary adnexal lesions, specifically eccrine carcinoma, porocarcinoma, hidradenocarcinoma, and microcystic adnexal carcinoma; however, in one report, none of the apocrine carcinomas were positive for p63, cytokeratin 15, or D2-40.¹⁹ Thus, while markers for some primary adnexal neoplasms are emerging, specific tests at the immunohistochemical level for the apocrine carcinoma subgroup are still lacking.

Conclusion

In summary, a conclusive distinction between primary cutaneous apocrine carcinoma and metastatic adenocarcinoma to the skin remains challenging. Although new markers provide more specificity and sensitivity for neoplasms of eccrine origin, these markers do not appear to differentiate between primary apocrine carcinoma and metastatic breast carcinoma. In this case, as in other recent reports, diagnosis remained dependent on the clinical course of the patient. Although considerable progress has been made regarding immunohistochemical analysis of these cases, additional markers, especially ones more specific for primary skin cancers with apocrine differentiation, are still needed.

Differentiation between a primary adnexal carcinoma and a metastatic carcinoma to the skin is a challenging yet critical task for dermatologists and pathologists. Carcinomas that have metastasized to the skin are a sign of widespread systemic involvement and poor prognosis, while primary adnexal carcinomas tend to progress with an indolent clinical course. Although many patients with cutaneous metastases from an internal primary neoplasm can expect a median survival of no more than 12 months,¹ patients with primary adnexal carcinomas are reported to have a 5-year survival rate of 95.5% for localized disease and 85% with spread to regional lymph nodes.² We report a case of multiple cutaneous neoplasms of unknown primary origin in a 71-year-old man and describe our approach to identification of the possible primary site as well as management of the disease.  

Case Report

A 71-year-old man initially presented to his primary physician for evaluation of a mass on the left side of the neck of 3 months' duration. On physical examination, a firm 2.5×3.0-cm nodule was noted at the anterior border of the trapezius muscle. Palpation of the thyroid revealed an additional right-sided nodule. The submandibular and parotid glands were unremarkable to palpation. The patient was referred to general surgery for biopsy, which revealed an infiltrating, moderately differentiated adenocarcinoma with extensive lymphatic permeation. Immunohistochemical staining for cytokeratin (CK) 7 was positive, while CK20 and thyroid transcription factor 1 were negative. A positron emission tomography/computed tomography (CT) fusion scan demonstrated 3 areas of enhanced uptake: one in the right side of the thyroid, a second corresponding to the mass on the left side of the neck at the level of the trapezius muscle, and a third in the left masseter muscle. Surgical excision with negative margins with possible chemotherapy was recommended; however, the patient declined treatment and was lost to follow-up until 2 years later when he presented to his primary physician with an additional lesion on his scalp.

Four years after the biopsy, the patient presented to the dermatology department with additional tumor nodules including a 4-cm, annular, indurated, focally eroded plaque on the left side of the lateral neck (Figure 1); 3 separate 1-cm nodules on the right side of the lateral neck; and an ulcerated, crusted, 10×8-cm plaque on the posterior aspect of the scalp. Despite the extensive lesions, the patient remained in good health and reported no recent weight loss or signs or symptoms of systemic involvement. The posterior scalp lesion, which developed 2 years after the initial appearance of the mass on the neck and was thought to represent a possible metastasis of the tumor, was biopsied and showed diffuse infiltration of the dermis by poorly differentiated tumor cells with vacuolated cytoplasm arranged in nests and cords and sometimes in a single-file arrangement (Figure 2). A CT scan demonstrated pretracheal lymphadenopathy as well as small intraparenchymal and subpleural pulmonary nodules throughout both lung fields.

Another scalp biopsy was taken. Tumor cells were negative on mucicarmine staining. Additional immunohistochemical staining, including a periodic acid-Schiff stain with diastase digestion for epithelial mucin revealed minimal luminal positivity. Immunostaining was positive for CK7, carcinoembryonic antigen, CD15, estrogen receptor, progesterone receptor, gross cystic disease fluid protein 15 (GCDFP-15), and mammaglobin, and negative for CK20, podoplanin, thyroid transcription factor 1, S-100 protein, p63, and prostate specific antigen. ERBB2 (formerly HER2/neu) staining was negative according to fluorescence in situ hybridization analysis. Tumor cells showed a Ki-67 nuclear proliferation index of greater than 50%, indicating progression to aggressive carcinoma. 

Based on the histological and immunochemical studies, the differential diagnosis included primary cutaneous apocrine carcinoma versus breast carcinoma; however, the prolonged clinical progression of these lesions favored a primary cutaneous adnexal tumor over a metastatic adenocarcinoma. Nevertheless, despite the initially indolent growth of the lesions over the first 5 years, the Ki-67 proliferation index and presence of widespread metastases on the posterior scalp indicated progression to an aggressive carcinoma. Chemotherapy was recommended as the treatment of choice. At his most recent follow-up visit 4 months later, the patient chose to begin treatment with tamoxifen and refused other treatment options.

Comment

The distinction between primary adnexal and metastatic adenocarcinomas of the skin is challenging both clinically and histologically. Some pathologists have argued that metastatic breast carcinomas and primary cutaneous apocrine carcinomas are essentially indistinguishable.³ Patients with cutaneous metastases, which occur in approximately 5.3% of all malignancies,⁴ typically can expect survival of no more than 12 months from the time of detection.¹ In contrast, primary apocrine carcinomas of the skin, though much less common, carry a remarkably better prognosis, with 5-year relative survival rates of 95.5% and 85.5% reported for patients with localized disease and spread to regional lymph nodes, respectively.²

Fewer than 100 cases of primary cutaneous adnexal (apocrine) carcinomas have been reported overall, with the earliest known report dating back to 1944.⁵ According to the literature, primary apocrine carcinomas were diagnosed at a median age of 66 years and were slightly more common in females than males.^2,6 Apocrine carcinomas were seen most frequently on the head, neck, and trunk,² generally presenting in the form of asymptomatic nodules or plaques of 2 to 3 cm in size, with gradual progression occurring over months to years.⁶ Approximately 40% of patients have been reported with positive regional lymph nodes at diagnosis. Treatment of apocrine carcinoma typically has involved local excision with clear margins with or without lymph node dissection. Chemotherapy and radiation therapy have shown no proven benefit.⁷

Currently, there is no standardized approach to evaluating patients with possible cutaneous metastasis versus primary cutaneous adnexal carcinomas. Imaging studies such as mammography and abdominal CT typically reveal an internal primary cancer in one-third of patients. However, additional studies such as gastrointestinal radiography, chest and pelvic CT, barium enema, and intravenous pyelogram have shown to be of limited value.⁸ Although specificity and sensitivity of immunohistochemistry is limited, a number of immunomarkers, including CK7 and CK20, are routinely studied to narrow the differential diagnosis of a cutaneous neoplasm of unclear origin. Urothelial, gastric, colorectal, and pancreatic carcinomas generally are positive for CK20; CK7-positive adenocarcinomas include salivary, non-small cell lung, breast, ovarian, pancreatic, endometrial, and transitional cell adenocarcinomas. Carcinomas negative for both CK7 and CK20 include colorectal, hepatocellular, renal cell, prostate, and squamous cell carcinoma of the lung. 

The presence of positive staining for estrogen and progesterone receptors as well as GCDFP-15 and mammaglobin raised the possibility of primary breast adenocarcinoma in our patient, but given that these markers can be positive in primary cutaneous adnexal tumors, immunohistochemistry results were not able to provide a definitive primary site. The overall staining pattern was nearly identical to 26 cases of primary cutaneous cribriform apocrine carcinoma, which was found to be positive for CK7 and carcinoembryonic antigen, and negative for CK20 and S-100. The only difference was in GCDFP-15 staining, which was positive in our case and negative in the cases of cribriform apocrine carcinoma.⁹ Histologic features favoring a primary apocrine origin include normal apocrine glands in the vicinity, glandular structures with decapitation secretion high in the dermis, and intracytoplasmic iron granules.¹⁰ Additionally, positive estrogen receptor staining appears to be much more common in apocrine carcinomas (5/10) than in eccrine carcinomas (1/7).¹¹

A number of other markers have been investigated for possible diagnostic utility for distinction between primary adnexal carcinomas and metastatic adenocarcinomas. The nuclear transcription factor p63, which plays a role in keratinocyte differentiation, is preferentially expressed in a number of primary adnexal carcinomas and is purported to be the most sensitive marker overall, with a sensitivity of 78% to 91%.^12-14 However, p63 has shown incomplete specificity for primary adnexal neoplasms, having been reported as positive in 11% to 22% of adenocarcinomas metastatic to skin.^15-18 Nestin and CK15, which are expressed in hair follicle progenitor cells, also are potential specific markers for some primary adnexal lesions, specifically eccrine carcinoma, porocarcinoma, hidradenocarcinoma, and microcystic adnexal carcinoma; however, in one report, none of the apocrine carcinomas were positive for p63, cytokeratin 15, or D2-40.¹⁹ Thus, while markers for some primary adnexal neoplasms are emerging, specific tests at the immunohistochemical level for the apocrine carcinoma subgroup are still lacking.

Conclusion

In summary, a conclusive distinction between primary cutaneous apocrine carcinoma and metastatic adenocarcinoma to the skin remains challenging. Although new markers provide more specificity and sensitivity for neoplasms of eccrine origin, these markers do not appear to differentiate between primary apocrine carcinoma and metastatic breast carcinoma. In this case, as in other recent reports, diagnosis remained dependent on the clinical course of the patient. Although considerable progress has been made regarding immunohistochemical analysis of these cases, additional markers, especially ones more specific for primary skin cancers with apocrine differentiation, are still needed.

The Health Frontiers in Tijuana (HFiT) clinic is a binational partnership between the University of California, San Diego School of Medicine (San Diego, California); the Universidad Autónoma de Baja California School of Medicine (Tijuana, Mexico); and Desayunador Salesiano Padre Chava, a community grassroots organization in Tijuana, Mexico. Health Frontiers in Tijuana provides accessible quality health care for the underserved in Tijuana's Zona Norte.¹ This article is a narrative meant to share my clinical experience as a dermatology resident who worked with HFiT to establish teledermatology services at this clinic.

Teledermatology in Tijuana

The patient population served by the HFiT clinic includes substance users, sex workers, the homeless, deportees, indigent patients, and recently Haitian immigrants.¹ We established teledermatology services under the faculty leadership of Casey Carlos, MD, who was awarded a SkinCare for Developing Countries grant from the American Academy of Dermatology in April 2015 to address the need for teledermatology support for the clinic.²

Over the last 2 years, we have worked closely with 2 medical students from the University of California, San Diego--Nicole Herrick, BS, and Nicole DeMartinis, BA--to apply for the grant and create a system whereby volunteer residents and faculty consultants at the University of California, San Diego, can provide teledermatology services on a weekly basis to support the HFiT staff as they see patients with dermatologic conditions. Initially, we purchased touch screen tablets to use the Africa Teledermatology Project (africa.telederm.org) web-based program. The clinic was already functioning with electronic medical records with volunteers who carried tablets and scribed for the providers as they saw patients. We felt this method would be a great way to incorporate teledermatology into the clinic, and it functioned moderately well for several weeks but was very labor intensive on our part, as we frequently had to travel to Tijuana to retrain rotating clinic volunteers on how to use the program. Often, the Internet connection was slow, which made pulling up the Africa Teledermatology Project website difficult, and photographs also would take too long to upload in the middle of a busy clinic.

We are now exploring how to use a more simple email format to send the teledermatology consultations while still being compliant with the Health Insurance Portability and Accountability Act. We currently use secure university email accounts. Although we are still working out the details, this email-based method seems to work well. It has been a simple solution to accommodate a slow Internet connection and many rotating volunteers without requiring additional training. The email format also allows the photographs to be saved in draft messages, even if the Internet connection times out.

Once the teledermatology consultation is sent, the medical students and I review them and then get an attending physician's input on our proposed working diagnosis and plan. We work to have this process complete within several days to return the answered consultation to the requesting provider.

Final Thoughts

The HFiT providers have shared a lot of positive verbal feedback about this project. One frequent comment is how helpful it is to have access to a dermatologist for challenging cases. We also have heard many times that this project has inspired medical students and volunteers to expand their knowledge of dermatology. We are continuing to form new collaborative relationships with physicians in Tijuana. We will soon have the ability to train primary care providers at HFiT on performing simple skin biopsies and managing basic dermatologic conditions. Through our support of these providers, we are creating a sustainable partnership that is mutually beneficial to the patients in Tijuana as well as the medical students and residents in the United States. It is highly rewarding to all those involved with this project, and I am excited to see what challenges this next year will bring as we welcome many new patients from Haiti into the HFiT patient population.

The Health Frontiers in Tijuana (HFiT) clinic is a binational partnership between the University of California, San Diego School of Medicine (San Diego, California); the Universidad Autónoma de Baja California School of Medicine (Tijuana, Mexico); and Desayunador Salesiano Padre Chava, a community grassroots organization in Tijuana, Mexico. Health Frontiers in Tijuana provides accessible quality health care for the underserved in Tijuana's Zona Norte.¹ This article is a narrative meant to share my clinical experience as a dermatology resident who worked with HFiT to establish teledermatology services at this clinic.

Teledermatology in Tijuana

The patient population served by the HFiT clinic includes substance users, sex workers, the homeless, deportees, indigent patients, and recently Haitian immigrants.¹ We established teledermatology services under the faculty leadership of Casey Carlos, MD, who was awarded a SkinCare for Developing Countries grant from the American Academy of Dermatology in April 2015 to address the need for teledermatology support for the clinic.²

Over the last 2 years, we have worked closely with 2 medical students from the University of California, San Diego--Nicole Herrick, BS, and Nicole DeMartinis, BA--to apply for the grant and create a system whereby volunteer residents and faculty consultants at the University of California, San Diego, can provide teledermatology services on a weekly basis to support the HFiT staff as they see patients with dermatologic conditions. Initially, we purchased touch screen tablets to use the Africa Teledermatology Project (africa.telederm.org) web-based program. The clinic was already functioning with electronic medical records with volunteers who carried tablets and scribed for the providers as they saw patients. We felt this method would be a great way to incorporate teledermatology into the clinic, and it functioned moderately well for several weeks but was very labor intensive on our part, as we frequently had to travel to Tijuana to retrain rotating clinic volunteers on how to use the program. Often, the Internet connection was slow, which made pulling up the Africa Teledermatology Project website difficult, and photographs also would take too long to upload in the middle of a busy clinic.

We are now exploring how to use a more simple email format to send the teledermatology consultations while still being compliant with the Health Insurance Portability and Accountability Act. We currently use secure university email accounts. Although we are still working out the details, this email-based method seems to work well. It has been a simple solution to accommodate a slow Internet connection and many rotating volunteers without requiring additional training. The email format also allows the photographs to be saved in draft messages, even if the Internet connection times out.

Once the teledermatology consultation is sent, the medical students and I review them and then get an attending physician's input on our proposed working diagnosis and plan. We work to have this process complete within several days to return the answered consultation to the requesting provider.

Final Thoughts

The HFiT providers have shared a lot of positive verbal feedback about this project. One frequent comment is how helpful it is to have access to a dermatologist for challenging cases. We also have heard many times that this project has inspired medical students and volunteers to expand their knowledge of dermatology. We are continuing to form new collaborative relationships with physicians in Tijuana. We will soon have the ability to train primary care providers at HFiT on performing simple skin biopsies and managing basic dermatologic conditions. Through our support of these providers, we are creating a sustainable partnership that is mutually beneficial to the patients in Tijuana as well as the medical students and residents in the United States. It is highly rewarding to all those involved with this project, and I am excited to see what challenges this next year will bring as we welcome many new patients from Haiti into the HFiT patient population.

The Health Frontiers in Tijuana (HFiT) clinic is a binational partnership between the University of California, San Diego School of Medicine (San Diego, California); the Universidad Autónoma de Baja California School of Medicine (Tijuana, Mexico); and Desayunador Salesiano Padre Chava, a community grassroots organization in Tijuana, Mexico. Health Frontiers in Tijuana provides accessible quality health care for the underserved in Tijuana's Zona Norte.¹ This article is a narrative meant to share my clinical experience as a dermatology resident who worked with HFiT to establish teledermatology services at this clinic.

Teledermatology in Tijuana

The patient population served by the HFiT clinic includes substance users, sex workers, the homeless, deportees, indigent patients, and recently Haitian immigrants.¹ We established teledermatology services under the faculty leadership of Casey Carlos, MD, who was awarded a SkinCare for Developing Countries grant from the American Academy of Dermatology in April 2015 to address the need for teledermatology support for the clinic.²

Over the last 2 years, we have worked closely with 2 medical students from the University of California, San Diego--Nicole Herrick, BS, and Nicole DeMartinis, BA--to apply for the grant and create a system whereby volunteer residents and faculty consultants at the University of California, San Diego, can provide teledermatology services on a weekly basis to support the HFiT staff as they see patients with dermatologic conditions. Initially, we purchased touch screen tablets to use the Africa Teledermatology Project (africa.telederm.org) web-based program. The clinic was already functioning with electronic medical records with volunteers who carried tablets and scribed for the providers as they saw patients. We felt this method would be a great way to incorporate teledermatology into the clinic, and it functioned moderately well for several weeks but was very labor intensive on our part, as we frequently had to travel to Tijuana to retrain rotating clinic volunteers on how to use the program. Often, the Internet connection was slow, which made pulling up the Africa Teledermatology Project website difficult, and photographs also would take too long to upload in the middle of a busy clinic.

We are now exploring how to use a more simple email format to send the teledermatology consultations while still being compliant with the Health Insurance Portability and Accountability Act. We currently use secure university email accounts. Although we are still working out the details, this email-based method seems to work well. It has been a simple solution to accommodate a slow Internet connection and many rotating volunteers without requiring additional training. The email format also allows the photographs to be saved in draft messages, even if the Internet connection times out.

Once the teledermatology consultation is sent, the medical students and I review them and then get an attending physician's input on our proposed working diagnosis and plan. We work to have this process complete within several days to return the answered consultation to the requesting provider.

Final Thoughts

The HFiT providers have shared a lot of positive verbal feedback about this project. One frequent comment is how helpful it is to have access to a dermatologist for challenging cases. We also have heard many times that this project has inspired medical students and volunteers to expand their knowledge of dermatology. We are continuing to form new collaborative relationships with physicians in Tijuana. We will soon have the ability to train primary care providers at HFiT on performing simple skin biopsies and managing basic dermatologic conditions. Through our support of these providers, we are creating a sustainable partnership that is mutually beneficial to the patients in Tijuana as well as the medical students and residents in the United States. It is highly rewarding to all those involved with this project, and I am excited to see what challenges this next year will bring as we welcome many new patients from Haiti into the HFiT patient population.