Desmoplastic Spitz nevus is a rare variant of Spitz nevus characterized by predominantly spindle-shaped or epithelioid nevus cells within the fibrotic stroma that can be confused with fibrous lesions. A 43-year-old woman presented with a 1-cm-sized dome-shaped papule on the dorsum of her left foot. The lesion showed histopathological features of a desmoplastic Spitz nevus with structures that resemble adenoma. Immunohistochemical staining was positive for S-100 protein, Melan-A, and SOX-10. Herein, we report this case because desmoplastic Spitz nevus is rare and can lead to confusion regarding the diagnosis of adnexal neoplasms.

Background: Oral ivermectin is an effective alternative to topical agents for scabies infestation, and may be beneficial in the treatment of crusted scabies in case of failure or impracticability of topical therapy. Objective: The present study aims to evaluate treatment outcomes of patients with scabies treated with oral ivermectin. Furthermore, we analyzed the efficacy and safety of oral ivermectin based on clinical characteristics. Methods: Overall, 16 patients with scabies received 200 μg/kg of ivermectin and topical scabicide (5% permethrin or 10% crotamiton) at 1-week intervals. Treatment outcome was evaluated by mineral oil test and medical examination at intervals of 1 or 2 weeks. If no improvement was observed at the follow-up, treatment was repeated. Results: All patients achieved a clinical response. The average number of administrations of ivermectin was 2.69, and the mode was 3 (n=8). The average number of administrations was higher for those over 70 years of age than for those under 70 years of age (2.80 vs. 2.50), but this was not statistically significant (p=0.558). There were no significant differences based on clinical type. The mean time from the first administration of ivermectin to the negative conversion of the mineral oil examination was 18.43±7.26 days. No adverse events were observed. Conclusion Oral ivermectin is an effective and safe therapy for treating human scabies.

Background: Guselkumab is a monoclonal antibody that selectively blocks the p19 subunit of interleukin-23. It has shown good efficacy and safety profile in several clinical trials of plaque psoriasis. However, studies on the efficacy of guselkumab in patients treated with other biologics are lacking. Objective: We aimed to investigate the efficacy and safety profile of guselkumab in patients with moderate-to-severe plaque psoriasis. We also compared the efficacy of guselkumab between biologic-naïve (Bio-Naïve) and biologicexperienced (Bio-Ex) patients. Methods: This multicenter, retrospective study included 72 patients treated with guselkumab. The patients’ clinical characteristics and psoriasis area and severity index (PASI) scores were recorded at each visit. The PASI90 and PASI100 responses and mean PASI scores were compared between the Bio-Naïve and Bio-Ex groups. Results: Fifty-five Bio-Naïve patients and 17 Bio-Ex patients were included in the study. At week 20, there were no significant differences in the PASI90 (64.2% vs. 53.8%) and PASI100 (28.3% vs. 15.4%) responses between the groups. However, at weeks 36 and 44, the PASI90 response (week 36: 89.2% vs. 36.4% and week 44: 97.8% vs. 63.6%) and the PASI100 response (week 36: 64.9% vs. 18.2% and week 44: 68.9% vs. 27.3%) were significantly higher in the Bio-Naïve group (p＜0.05). There were no differences in PASI90 and PASI100 responses between the groups in terms of other clinical characteristics and comorbidities at week 20. Conclusion The efficacy of guselkumab remained consistent among patients in whom other biologics had failed. However, the efficacy was slightly lower in the Bio-Ex group than in the Bio-Naïve group.