Background: Lichenoid drug eruption (LDE) is a relatively rare form of cutaneous drug eruption and that resembles lichen planus on a clinical and histological basis. Although there are some studies on histopathological findings of LDE, studies on clinical findings of LDE are limited. Objective: To investigate the clinical and histopathologic findings and prognosis of LDE. Methods: We retrospectively investigated the clinicopathologic findings of LDE patients who visited Kosin University Gospel Hospital between 1990 and 2020. Results: This study included 44 LDE patients (male:female=1.4:1). The most common causative drug was anti-tuberculous drugs (52.3%), followed by 5-fluorouracil (11.4%), and captopril (9.1%). There were pruritic erythematous scaly or lichenoid patches and plaques in all cases. The most frequently involved sites were trunk and extremities. Notably, 15 cases (34.1%) involving the scalp and 3 cases (6.8%) involving the oral mucosa. Treatment modalities included oral, topical corticosteroid, and oral antihistamines. Among 44 cases, 28 patients discontinued the causative agent, and 16 patients continued to use it after diagnosis of LDE. The mean duration of treatment for patients who discontinued or did not discontinue the causative drugs was 4, 10 weeks, respectively. The most commonly observed histopathologic findings were superficial and deep perivascular infiltration of inflammatory cells (100.0%) and eosinophil infiltration (93.2%). Conclusion LDE can be differentiated from idiopathic lichen planus by clinicopathologic findings. LDE appears to be a mild form of drug eruption in which symptoms can be controlled with conservative treatment, even without the cessation of causative drugs for the treatment of the underlying disease.

Background: The etiology and pathogenesis of lichen planus (LP) are not fully understood. Several studies have reported varying prevalence of anti-hepatitis C virus antibody (anti-HCV Ab) in LP. The relationship between LP and HCV infection remains controversial. Objective: To investigate the relationship between LP and HCV infection in Busan and Gyeongnam, Korea. Methods: We reviewed the medical records of 84 outpatients with LP and 84 control subjects (age- and sex-matched) from 2000 to 2020. Data on age, sex, duration of disease, distribution, shape, systemic diseases, and serology of anti-HCV Ab were collected. Results: The prevalence of anti-HCV Ab was 1.2% and 9.5% in the control group and patients with LP, respectively. Compared with the control group, patients with LP had a higher risk of HCV infection with an odds ratio of 8.737 (p=0.034). The mean duration of disease for the eight patients with HCV-associated LP was 5.8 months, which was shorter than 15.8 months in 84 patients with LP alone. Mucosal erosive LP was observed most frequently in HCV-associated LP with an odds ratio of 9.273 (p=0.003). Conclusion HCV infection may be clinically relevant to the development of LP. Furthermore, HCV infection may accelerate the progression of LP and is possibly related to the mucosal erosive subtype. Therefore, dermatologists should perform an anti-HCV Ab screening test for patients with LP, disclosing the potential association between LP and HCV infection.

Background: The etiology and pathogenesis of lichen planus (LP) are not fully understood. Several studies have reported varying prevalence of anti-hepatitis C virus antibody (anti-HCV Ab) in LP. The relationship between LP and HCV infection remains controversial. Objective: To investigate the relationship between LP and HCV infection in Busan and Gyeongnam, Korea. Methods: We reviewed the medical records of 84 outpatients with LP and 84 control subjects (age- and sex-matched) from 2000 to 2020. Data on age, sex, duration of disease, distribution, shape, systemic diseases, and serology of anti-HCV Ab were collected. Results: The prevalence of anti-HCV Ab was 1.2% and 9.5% in the control group and patients with LP, respectively. Compared with the control group, patients with LP had a higher risk of HCV infection with an odds ratio of 8.737 (p=0.034). The mean duration of disease for the eight patients with HCV-associated LP was 5.8 months, which was shorter than 15.8 months in 84 patients with LP alone. Mucosal erosive LP was observed most frequently in HCV-associated LP with an odds ratio of 9.273 (p=0.003). Conclusion HCV infection may be clinically relevant to the development of LP. Furthermore, HCV infection may accelerate the progression of LP and is possibly related to the mucosal erosive subtype. Therefore, dermatologists should perform an anti-HCV Ab screening test for patients with LP, disclosing the potential association between LP and HCV infection.

Spark’s nevus is a compound word composed of Spitz nevus and Clark’s nevus. It is one of the combined melanocytic nevi which is more common in female and usually presents as a sharp circumscribed hyperpigmented macule on the lower extremities. On histopathologic findings, both cytologic features of Spitz nevus characterized as large spindle or epithelioid melanocytes containing large nuclei with abundant cytoplasm, and architecture of Clark’s nevus characterized as elongation of rete ridges, bridging of the nests, concentric and lamellar fibrosis can be seen. A 24-year-old female presented with an asymptomatic, solitary, dark-brown-colored papule surrounded by brownish patch that looked similar to dysplastic nevus or malignant melanoma on the buttock. On dermoscopic examination, it showed brown-to-black globules, diffuse homogenous pigmentation with blue-white structures, and a surrounding brownish reticular pattern that faded away. On histopathologic findings, overall asymmetrical structure, epithelioid large melanocytes containing large nuclei with abundant cytoplasm, and Kamino body were seen in the central portion. Also, lentiginous hyperplasia, bridging of the nests composed of melanocytes containing foamy cytoplasm, concentric and lamellar fibrosis along with the elongation of rete ridge, and perivascular lymphocytic infiltration were seen in the peripheral portion. The diagnosis of Spark’s nevus was made. Following its definition, this combined nevus is diagnosed histopathologically, but the clinicodermoscopic features have not been well described. Herein, we report a case of Spark’s nevus in which dermoscopy was helpful for differentiating it from malignant melanoma.

BACKGROUND: Folliculotropic mycosis fungoides (FMF) is a variant of mycosis fungoides (MF) that is characterized clinically by variable types of skin eruptions, including plaques, acneiform lesions, and alopecic patches. Histopathologically, FMF is characterized by folliculotropic infiltrates. OBJECTIVE: This study was conducted to scrutinize the clinical and histopathologic features of FMF in Koreans and the responses to phototherapy. METHODS: Twenty Koreans diagnosed with MF who had histopathologic evidence of folliculotropism were enrolled. RESULTS: Eighteen patients had head-and-neck-region infiltration, while five had solitary lesion. In all patients, the atypical lymphocytic infiltrate had a perifollicular distribution. Twelve patients were treated with ultraviolet A (UVA)-1. Eleven of these 12 patients with early-stage FMF experienced >80% improvement (8: complete remission; 3: partial remission). Four patients, including 2 who relapsed after UVA-1, were treated with photodynamic therapy (PDT), reaching complete remission after PDT. CONCLUSION: As FMF has variable clinical presentations, skin biopsy is required to confirm the diagnosis. And both UVA-1 and methyl aminolevulinate-PDT are clinically effective in treatment of early-stage FMF.
Biopsy ; Diagnosis ; Humans ; Mycosis Fungoides* ; Photochemotherapy* ; Phototherapy ; Skin

In the originally published version of this article, complete anonymity was not achieved.

BACKGROUND: An epidermal cyst is a common keratin-filled epithelial-lined cyst. The treatment of choice for epidermal cysts is surgical excision. If the cyst becomes ruptured, incision and drainage with oral antibiotic therapy or intralesional steroid injection are required. OBJECTIVE: To analyze the dermoscopic features that can differentiate between ruptured and unruptured epidermal cysts. METHODS: The clinical and dermoscopic features of the pathologically confirmed epidermal cysts of two subgroups of 38 patients, 20 with unruptured cysts and 18 with ruptured cysts, were reviewed. RESULTS: With regard to the dermoscopic features, an ivory- white background color and punctum were commonly found in both groups (p>0.05). The unruptured-cyst group showed higher frequencies of pore sign (p<0.05), blue-white veil (p>0.05), no vascular structure, and arborizing telangiectasia (p<0.05), but the ruptured-cyst group usually had red lacunae (p>0.05) and peripheral linear branched vessels (with an erythematous rim) (p<0.05). CONCLUSION: Dermoscopy is helpful in differentiating between ruptured and unruptured epidermal cysts.
Dermoscopy* ; Diagnosis, Differential* ; Drainage ; Epidermal Cyst* ; Humans ; Telangiectasis

BACKGROUND: An epidermal cyst is a common keratin-filled epithelial-lined cyst. The treatment of choice for epidermal cysts is surgical excision. If the cyst becomes ruptured, incision and drainage with oral antibiotic therapy or intralesional steroid injection are required. OBJECTIVE: To analyze the dermoscopic features that can differentiate between ruptured and unruptured epidermal cysts. METHODS: The clinical and dermoscopic features of the pathologically confirmed epidermal cysts of two subgroups of 38 patients, 20 with unruptured cysts and 18 with ruptured cysts, were reviewed. RESULTS: With regard to the dermoscopic features, an ivory- white background color and punctum were commonly found in both groups (p>0.05). The unruptured-cyst group showed higher frequencies of pore sign (p<0.05), blue-white veil (p>0.05), no vascular structure, and arborizing telangiectasia (p<0.05), but the ruptured-cyst group usually had red lacunae (p>0.05) and peripheral linear branched vessels (with an erythematous rim) (p<0.05). CONCLUSION: Dermoscopy is helpful in differentiating between ruptured and unruptured epidermal cysts.
Dermoscopy* ; Diagnosis, Differential* ; Drainage ; Epidermal Cyst* ; Humans ; Telangiectasis