Background: Primary cutaneous CD30+ lymphoproliferative disorders (pcCD30-LPDs) are a diseases with various clinical and prognostic characteristics. Objective: Increasing our knowledge of the clinical characteristics of pcCD30-LPDs and identifying potential prognostic variables in an Asian population. Methods: Clinicopathological features and survival data of pcCD30-LPD cases obtained from 22 hospitals in South Korea were examined. Results: A total of 413 cases of pcCD30-LPDs (lymphomatoid papulosis [LYP], n=237; primary cutaneous anaplastic large cell lymphoma [C-ALCL], n=176) were included. Ninety percent of LYP patients and roughly 50% of C-ALCL patients presented with multiple skin lesions. Both LYP and C-ALCL affected the lower limbs most frequently. Multiplicity and advanced T stage of LYP lesions were associated with a chronic course longer than 6 months. Clinical morphology with patch lesions and elevated serum lactate dehydrogenase were significantly associated with LPDs during follow-up in LYP patients. Extracutaneous involvement of C-ALCL occurred in 13.2% of patients. Lesions larger than 5 cm and increased serum lactate dehydrogenase were associated with a poor prognosis in C-ALCL. The survival of patients with C-ALCL was unaffected by the anatomical locations of skin lesions or other pathological factors. Conclusion The multiplicity or size of skin lesions was associated with a chronic course of LYP and survival among patients with C-ALCL.

Background: Primary cicatricial alopecia (PCA) is a group of disorders causing irreversible hair loss because of hair follicle destruction. Although bacterial colonization is suspected to contribute to PCA pathogenesis, its role remains unclear. Objective: To investigate bacterial colonization patterns and antibiotic susceptibility profiles in patients with PCA compared to those with non-inflammatory scalp conditions. Methods: This retrospective study analyzed bacterial cultures from scalp swabs of 161 subjects (68 patients with PCA and 93 controls) at a tertiary hospital between June 2011 and December 2023. Bacterial species and antibiotic resistance rates were evaluated using subgroup analyses of neutrophilic PCA (NCA). Results: PCA cultures showed a higher prevalence of Staphylococcus aureus (24.3%) and S. lugdunensis (8.1%) than controls, where S. capitis (54.5%) was predominant. Gram-negative bacteria were more frequent in the PCA group (13.5%) than in the control group (9.9%), with Klebsiella spp.(10.9%) being the most prevalent. Resistance rates were significantly higher in PCA for benzylpenicillin, fusidic acid, erythromycin, clindamycin, oxacillin, and telithromycin (p<0.05). Methicillin-resistant S. aureus was identified in 15% of S. aureus isolates from NCA cases. Gram-negative bacteria in PCA also exhibited increased resistance to ampicillin and ampicillin/sulbactam. Conclusion PCA exhibits distinct bacterial colonization and elevated antibiotic resistance, particularly in the neutrophilic subtypes. Bacterial culture and susceptibility testing are essential for targeted therapies in clinical practice. Further multicenter microbiome analyses with mechanistic studies are needed to elucidate bacterial contributions to PCA pathogenesis.

Background: The number of general cosmetic practitioners impersonating dermatologists in Korea has increased, leading to serious harm that is significant enough to attract the attention of health authorities, which dermatologists are deeply concerned about. Objective: We conducted a survey targeting dermatologists to gather their opinions on the behavior, problems, and countermeasures of general cosmetic practitioners disguising themselves as dermatologists. Methods: A total of 280 dermatologists completed the survey between January and February 2024. The questions covered demographic characteristics, experiences of cosmetic general practitioners falsely introduced themselves as dermatologists, complications experienced by patients who received treatment after being mistaken for a dermatologist, the seriousness of the problem for cosmetic general practitioners impersonating dermatologists, and the relationship between the shortage of essential medical personnel and the phenomenon of cosmetic general practitioners disguising themselves as dermatologists. Results: Despite cases in which cosmetic general practitioners impersonate dermatologists, most dermatologists have not responded appropriately in many instances. Dermatologists have reported many cases of complications after receiving dermatological treatment from such cosmetic general practitioners. Most dermatologists are concerned about the serious problems of general cosmetic practitioners, disguising themselves as dermatologists and anticipating many adverse effects. Conclusion We believe that we need to pool our wisdom to solve these problems and expect that this study will provide valuable basic data for solving these problems in the dermatology and medical environments of Korea.

Background: The number of general cosmetic practitioners impersonating dermatologists in Korea has increased, leading to serious harm that is significant enough to attract the attention of health authorities, which dermatologists are deeply concerned about. Objective: We conducted a survey targeting dermatologists to gather their opinions on the behavior, problems, and countermeasures of general cosmetic practitioners disguising themselves as dermatologists. Methods: A total of 280 dermatologists completed the survey between January and February 2024. The questions covered demographic characteristics, experiences of cosmetic general practitioners falsely introduced themselves as dermatologists, complications experienced by patients who received treatment after being mistaken for a dermatologist, the seriousness of the problem for cosmetic general practitioners impersonating dermatologists, and the relationship between the shortage of essential medical personnel and the phenomenon of cosmetic general practitioners disguising themselves as dermatologists. Results: Despite cases in which cosmetic general practitioners impersonate dermatologists, most dermatologists have not responded appropriately in many instances. Dermatologists have reported many cases of complications after receiving dermatological treatment from such cosmetic general practitioners. Most dermatologists are concerned about the serious problems of general cosmetic practitioners, disguising themselves as dermatologists and anticipating many adverse effects. Conclusion We believe that we need to pool our wisdom to solve these problems and expect that this study will provide valuable basic data for solving these problems in the dermatology and medical environments of Korea.

Background: The number of general cosmetic practitioners impersonating dermatologists in Korea has increased, leading to serious harm that is significant enough to attract the attention of health authorities, which dermatologists are deeply concerned about. Objective: We conducted a survey targeting dermatologists to gather their opinions on the behavior, problems, and countermeasures of general cosmetic practitioners disguising themselves as dermatologists. Methods: A total of 280 dermatologists completed the survey between January and February 2024. The questions covered demographic characteristics, experiences of cosmetic general practitioners falsely introduced themselves as dermatologists, complications experienced by patients who received treatment after being mistaken for a dermatologist, the seriousness of the problem for cosmetic general practitioners impersonating dermatologists, and the relationship between the shortage of essential medical personnel and the phenomenon of cosmetic general practitioners disguising themselves as dermatologists. Results: Despite cases in which cosmetic general practitioners impersonate dermatologists, most dermatologists have not responded appropriately in many instances. Dermatologists have reported many cases of complications after receiving dermatological treatment from such cosmetic general practitioners. Most dermatologists are concerned about the serious problems of general cosmetic practitioners, disguising themselves as dermatologists and anticipating many adverse effects. Conclusion We believe that we need to pool our wisdom to solve these problems and expect that this study will provide valuable basic data for solving these problems in the dermatology and medical environments of Korea.

Background: The number of general cosmetic practitioners impersonating dermatologists in Korea has increased, leading to serious harm that is significant enough to attract the attention of health authorities, which dermatologists are deeply concerned about. Objective: We conducted a survey targeting dermatologists to gather their opinions on the behavior, problems, and countermeasures of general cosmetic practitioners disguising themselves as dermatologists. Methods: A total of 280 dermatologists completed the survey between January and February 2024. The questions covered demographic characteristics, experiences of cosmetic general practitioners falsely introduced themselves as dermatologists, complications experienced by patients who received treatment after being mistaken for a dermatologist, the seriousness of the problem for cosmetic general practitioners impersonating dermatologists, and the relationship between the shortage of essential medical personnel and the phenomenon of cosmetic general practitioners disguising themselves as dermatologists. Results: Despite cases in which cosmetic general practitioners impersonate dermatologists, most dermatologists have not responded appropriately in many instances. Dermatologists have reported many cases of complications after receiving dermatological treatment from such cosmetic general practitioners. Most dermatologists are concerned about the serious problems of general cosmetic practitioners, disguising themselves as dermatologists and anticipating many adverse effects. Conclusion We believe that we need to pool our wisdom to solve these problems and expect that this study will provide valuable basic data for solving these problems in the dermatology and medical environments of Korea.

Background/Aims: A poor prognostic factor for Crohn’s disease (CD) includes perianal fistulizing disease, including perianal fistula and/or perianal abscess. Currently, a tool to assess perianal symptoms in patients with CD remains nonexistent. This study aimed to develop a perianal fistulizing disease self-screening questionnaire for patients with CD. Methods: This prospective pilot study was conducted at three tertiary referral centers between January 2019 and May 2020. We formulated questions on perianal symptoms, including tenesmus, anal discharge, bleeding, pain, and heat. A 4-point Likert scale was used to rate each question. Patients with CD completed a questionnaire and underwent pelvic magnetic resonance imaging (MRI). Results: Overall, 93 patients were enrolled, with 51 (54.8%) diagnosed with perianal fistulizing disease, as determined by pelvic MRI. The Spearman correlation findings demonstrated that anal pain (p = 0.450, p < 0.001) and anal discharge (p = 0.556, p < 0.001) were the symptoms that most significantly correlated with perianal disease. For anal pain and discharge, the area under the receiver operating characteristic curve of the scores was significantly higher than that of the combined score for all five symptoms (0.855 vs. 0.794, DeLong’s test p = 0.04). For the two symptoms combined, the sensitivity, specificity, and positive predictive and negative predictive values were 88.2, 73.8, 80.4, and 83.8%, respectively, with 81.7% accuracy for detecting perianal fistulizing disease. Conclusions This study indicates that simple questions regarding anal pain and discharge can help accurately identify the presence of perianal fistulizing disease in patients with CD.

Tinea capitis is an infection of the scalp hair follicles and surrounding skin that primarily occurs in prepubertal children. Microsporum canis remains the most common pathogen causing tinea capitis in Asian countries, including South Korea, although the causative organism of this condition varies across geographical regions and time periods. Systemic antifungal agents are the mainstay treatments for tinea capitis; however, the therapeutic responses to antifungal drugs may vary depending on the causative species, and treatment failure may occur owing to drug resistance. Although dermatophytosis resistant to clinical treatment have been increasingly encountered, recalcitrant tinea capitis cases have rarely been reported. Herein, we report three cases of tinea capitis caused by M. canis in children. All three patients showed unsatisfactory clinical responses to prolonged courses of oral terbinafine or itraconazole without achieving mycological cure; however, they were successfully treated with oral griseofulvin. Although griseofulvin is not currently available or licensed for use in many countries, including South Korea, it is one of the most effective agents against Microsporum species and remains the most widely used first-line treatment for tinea capitis in children, based on dermatology textbooks and reliable treatment guidelines.

Background: Pityriasis rotunda (PR) is a rare dermatosis characterized by the presence of multiple, strikingly circular or oval-shaped, sharply demarcated, and scaly hyperpigmented patches. Its etiology remains poorly understood. To date, there have been no comprehensive analyses of PR in Koreans. Objective: To investigate the clinical, pathological, and dermoscopic features of PR. Methods: Sixteen patients with PR were evaluated. Results: A female preponderance was observed (male:female ratio 1:7), and the mean age of the patients was 33.2±16.1 years (range, 15∼68 years), with the peak incidence observed in patients in their 20s. Notably, all the lesions developed on the trunk. The most common clinical diagnosis is PR. Histologically, PR appears similar to ichthyosis vulgaris. Hyperkeratosis was mainly ortho-keratotic, with plugs observed within hair follicles, elongated rete ridges, diminished stratum granulosum, enhanced pigmentation of the basal layer, pigmentary incontinence, and sparse superficial perivascular lymphoid cell inflammatory infiltrate. Periodic acid-Schiff staining was negative for fungi. Hyperpigmented patches with occasional scales were separated from each other by paler striae on dermoscopy. Conclusion PR commonly presents as multiple round lesions of variable sizes on the trunk of patients in their 20s. They showed characteristic findings, including hyperkeratosis with relative focal hypogranulosis, histopathologically, and some lesions showed dark and light brown polygonal patches with paler striae arranged dermoscopically, in a mosaic pattern. This was a retrospective single-center study with a small sample size; however, we believe that this paper will contribute to the clarification and understanding of PR.