Background: Basal cell carcinoma (BCC) is the most common type of skin cancer. However, limited comparative data on the characteristics and prognosis of BCC in the H-zone and non-H-zone exist.
Objective: We aimed to compare the clinical, histopathological, and surgical characteristics of BCCs in the head and neck region between the H- and non-H-zones.
Methods: We retrospectively reviewed the clinical and histopathological characteristics of 292 head and neck BCC lesions in 275 patients and the characteristics of Mohs micrographic surgery (MMS) of 252 BCC lesions in 239 patients.
Results: In the H-zone, 226 lesions (77.4%) were found. Clinically, patients with H-zone BCC, compared to those with non-H-zone, were significantly older (71.6±11.4 years vs. 64.6±13.5 years) and smaller in diameter (10.1±7.1 mm vs. 12.4±9.9 mm). The noduloulcerative type was more frequent in the H-zone, while the superficial and morpheaform types in the non-H-zone. Histopathologically, the infiltrative subtype was particularly noted in the H-zone than the non-H-zone (7.5% vs. 1.5%). Out of 37 BCC patients with prior treatment history, 31 (83.8%) were in the H-zone. Two out of 252 lesions (0.8%) recurred after MMS at our institution. The mean stages of MMS were comparable between the H- and non-H-zones (1.59 vs. 1.45, p=0.135).
Conclusion: H-zone BCCs were associated with older age and smaller tumor size compared to the non-H-zone BCCs. The noduloulcerative clinical and nodulocystic pathologic subtypes were the most common in both H-zone and non-H-zone BCCs. (Korean J Dermatol 2021;59(10):735∼741)

Background: Digital mucous cysts (DMCs) are benign, occurring mainly on the fingers but rarely on the toes. Although the exact cause of DMC has not been identified, it is classified into two different types based on its pathogenesis and location. Surgical and nonsurgical procedures, including aspiration, sclerotherapy, steroid injection, cryotherapy, and CO2 laser, can be used to treat DMC.
Objective: This study aimed to compare treatment response based on DMC type and evaluate its efficacy in surgical and nonsurgical (sclerotherapy) treatments.
Methods: We retrospectively reviewed the electronic medical records of patients with DMC who visited our dermatology department between January 2010 and November 2020.
Results: This study enrolled 39 patients having a mean age of 59.2 years. The proportion of female patients (21/39, 53.8%) was more than male (18/39, 46.2%). The DMC occurrence was more frequent in the fingers (32/39, 82.1%), especially in the index and middle fingers than in the toes (7/39, 17.9%). In sclerotherapy, DMC in the distal interphalangeal joint (DIPJ) required more treatment than that in the proximal nail fold (PNF) (p<0.05). The number of treatments using sclerotherapy was higher compared to that of surgical treatments (p<0.05).
Conclusion: The DIPJ type of DMC patients was more difficult to treat using sclerotherapy than the PNF type. Moreover, surgical treatment has a better response than sclerotherapy. (Korean J Dermatol 2021;59(10):742∼748)

Background: Psoriasis is a chronic inflammatory autoimmune disease. Some studies have demonstrated a relationship of psoriasis with vitamin D (Vit D) deficiency or serum lipid levels.
Objective: We aimed to compare serum levels of Vit D and lipids in patients with active psoriasis and control subjects. Additionally, we analyzed the relationship of disease severity with serum Vit D and lipid levels.
Methods: A total of 243 patients were retrospectively analyzed. Statistical data were evaluated, and the values were considered significant at p<0.05.
Results: Statistically significant difference in Vit D levels between the psoriasis (n=117) and the control groups (n=126) was not found. In addition, an association between Vit D levels and the disease severity, using the psoriasis area and severity index (PASI) was not observed. The proportion of overweight patients (body mass index [BMI]≥ 23 kg/m2) was higher in the psoriasis group than in the control group, and there was a significant relationship between the increase in PASI and the serum triglycerides (TG) levels (p<0.05).
Conclusion: The psoriasis and control groups did not show a statistical difference in serum Vit D levels. In the subgroup analysis of cases with normal BMI, excluding the underlying disease, no significant difference in Vit D levels between the two groups was observed. However, the association of psoriasis with factors, such as BMI and TG, was found to be significant; hence, these could be therapeutic targets in patients with psoriasis to improve their quality of life. Controlled and well-designed studies are required in the future. (Korean J Dermatol 2021;59(10):749∼760)

Background: Epidermal growth factor (EGF) stimulates wound healing in various skin conditions, and EGFcontaining formulations can promote wound regeneration and help reduce complications after laser treatment.
Objective: To evaluate the effect of EGF-containing ointment on wound regeneration after ablative laser treatment and laser-induced postinflammatory erythema (PIE) and hyperpigmentation (PIH).
Methods: Twenty-five patients who required treatment with ablative laser on both sides of the face were enrolled and underwent one session of laser treatment. Postoperatively, all patients were instructed to apply the EGFcontaining ointment on the randomly assigned-hemifacial side, while gentamicin cream was applied on the opposite side. Investigators' global assessment (IGA), evaluating general wound condition, erythema, pigmentation, and scab shedding, and patient's global assessment (PGA), evaluating patient satisfaction with clinical improvement, were both measured at 1 week and 4 weeks after treatment. Objective assessments, including melanin index (MI), erythema index (EI), skin hydration, and transepidermal water loss (TEWL), were measured before treatment and at 1 week and 4 weeks after treatment.
Results: The EGF-containing ointment showed better outcomes with IGA (1 week; p=0.02, 4 weeks; p=0.002) and PGA (1 week; p=0.04, 4 weeks; p=0.01) scores compared to gentamicin cream. Compared to gentamicin cream, treatment with EGF-containing ointment resulted in significantly lower EI (p=0.044) and MI (p=0.023), but skin hydration and TEWL between the two groups exhibited nonsignificant differences.
Conclusion: EGF-containing ointment could be an effective adjuvant option for wound regeneration after ablative laser treatment and minimizing laser-induced PIE and PIH in Asian patients. (Korean J Dermatol 2021;59(10):761∼769)

Background: Patients with rosacea usually suffer from skin irritations, such as itching, stinging, burning, and pain. These symptoms may be related to the skin barrier function disruption.
Objective: We investigated the skin barrier functions in patients with mild to moderate rosacea and the associated improvements based on the skin care habit modifications and treatment modalities.
Methods: We analyzed the data on transepidermal water loss (TEWL) and stratum corneum hydration (SCH) of skin lesions in 27 patients with rosacea and healthy skin of 29 control subjects. We compared the results of TEWL and SCH based on sex, age, type of rosacea, skin care habits, and the treatment modalities.
Results: The skin in the patients with rosacea exhibited increased TEWL and decreased SCH compared with that in control subjects. Male patients showed increased TEWL and decreased SCH compared to female patients. Combination therapy with systemic minocycline and topical metronidazole improved the skin barrier functions. Patients with better skin care habits presented better skin barrier functions and clinical improvement.
Conclusion: Patients with rosacea, especially those with poor skin care habits, showed reduced skin barrier functions. Appropriate skin care habits with cleansers and moisturizers are recommended for the management of rosacea. (Korean J Dermatol 2021;59(10):770∼777)

Background: Trichotillomania (TTM) is characterized by recurrent hair pulling, resulting in hair loss. TTM is typically encountered in dermatology settings; however, few reports on the clinical characteristics of TTM in a large population are available.
Objective: To evaluate the clinical characteristics of TTM.
Methods: We performed a retrospective chart review of patients diagnosed with TTM between 2006 and 2019.
Results: Clinical records of 198 patients were analyzed. The average age of TTM onset was 10.8 years, and 119 patients experienced childhood-onset (at <12 years). Sex prevalence showed a female predominance, and the proportion of females was lower in the childhood-onset TTM than in the late-onset TTM (onset at ≥12 years). Vertex was the most commonly involved site. A history of stressful situations was noted in 48 patients (24.2%). In the group with a poor prognosis, the number of patients with ≥25% scalp invasion was significantly more than the other group. The average duration of hair loss to more than 50% recovery was 4.88 months for childhood-onset TTM cases and 9.83 months for late-onset TTM cases. The prognosis was significantly better in the childhood-onset TTM than in the late-onset TTM. Nail biting and folliculitis were the most common co-occurring repetitive behavior and comorbid disease, respectively.
Conclusion: Unlike previous domestic studies, patients with childhood-onset TTM had a female preponderance. Moreover, the proportion of patients who experienced a stressful situation was higher than that reported in a previous study. In addition, patients with severe disease and late-onset TTM had a significantly poorer prognosis. (Korean J Dermatol 2021;59(10):778∼784)

Background: Cosmetic units are designated based on their similarity in topographic anatomy, texture and color, solar exposure, hair density, and sebaceous features. The difference of such features in facial port-wine stain (PWS) cases can affect the response to pulsed dye laser (PDL) treatment.
Objective: To evaluate the response of facial PWS to PDL treatment based on the underlying cosmetic units.
Methods: A retrospective study was conducted on 18 patients with facial PWS who received PDL treatment. For clinical assessment, three dermatologists evaluated the photographs taken before each treatment session. The response grade was assigned according to the quartile grading scale. The lesion was classified based on the underlying cosmetic units.
Results: The cheek was the most (50%) commonly involved area. All PWS (6/6) confined to one cosmetic unit showed a marked improvement compared with 16% PWS (2/12) affecting two or more units (p<0.05). Patients with PWS within one cosmetic unit required fewer treatment sessions to achieve marked improvement.
Conclusion: PWS confined to a single cosmetic unit than that located in two or more units responded better to PDL treatment. Before PDL treatment for facial PWS, age, initial lesion size, as well as the number of cosmetic units affected by the lesion should be considered. (Korean J Dermatol 2021;59(10):785∼792)

A 47-year-old man with a 25-year history of Crohn's disease, presenting asymptomatic erythematous scaly patches (size, 1∼3 cm in diameter) on his back, left hand, right wrist, left ankle, and left sole, visited our clinic. Histopathological examination of the lesions revealed Bowen's disease. Herein, we report a rare case of multiple Bowen's disease in the skin, away from the anogenital region, in a patient with Crohn's disease. (Korean J Dermatol 2021;59(10):793∼796)

Granuloma annulare (GA) is a common non-infectious granulomatous disease. Generalized GA is the second most common variant of GA. It is often associated with recalcitrant disease progression despite treatment. The lesion of generalized GA typically presents widespread papules that coalesce to form annular plaques over the whole body. We report a case of a patient with disseminated papules and coalescing annular plaques, primarily involving the intertriginous area and mimicking tinea corporis or cruris. Histopathological findings confirmed the lesion as GA. This case underscored the unusual clinical presentation of generalized GA. A case of GA localized to the intertriginous area has rarely been reported. Given the recalcitrant nature of the disease, dermatologists should consider generalized GA as a differential diagnosis in patients with an annular lesion involving the intertriginous area. Thus, we report this as an atypical case of generalized GA localized to the intertriginous area. (Korean J Dermatol 2021;59(10):797∼800)

Lyme disease caused by Borrelia species is transmitted via infected tick bites. Erythema migrans, a typical skin lesion on the tick-bitten site, is a hallmark of Lyme disease. A 63-year-old female presented an erythematous, semi-circular patch in the left inguinal area. It disappeared spontaneously without treatment. However, after 3 months, an erythematous patch with a diameter of 1 cm recurred on the left thigh. B. burgdorferi antibody testing revealed positive results. At the second visit, doxycycline was prescribed, and the skin lesion was resolved. However, the patient exhibited persistent systemic symptoms, including arthralgia and fatigue, and was diagnosed with post-treatment Lyme disease syndrome (PTLDS). The PTLDS prognosis is associated with delayed diagnosis. Thus, antibiotic treatment should be promptly initiated after suspecting Lyme disease to minimize the associated systemic symptoms. PTLDS diagnosis should be followed by proper medical care to alleviate the symptoms. (Korean J Dermatol 2021;59(10):801∼804)