Supplementary Material for: Addressing Diagnostic and Therapeutic Challenges in a case of Concurrent Tinea and Plaque Psoriasis

Introduction: The annular lesions of dermatophytosis can closely resemble the plaques of psoriasis, posing significant diagnostic and treatment challenges. Methotrexate, a common treatment for psoriasis, can exacerbate the former due to its immunosuppressive effects.
Case report: A middle- aged man with chronic plaque psoriasis was on tablet methotrexate (7.5mg once weekly) and topical steroids for one year. Despite some improvement, new annular lesions emerged whenever topical steroids were tapered. Frustrated with the lack of disease control, the patient finally visited a tertiary care centre, where tinea corporis was diagnosed alongside psoriasis via dermoscopy, mycological tests, and histopathology. Methotrexate and steroids were discontinued, and the patient was started on antifungals. Once the dermatophytosis was brought under control, methotrexate was resumed alongside targeted application of steroid and antifungal creams.
Conclusion: The coexistence of tinea corporis and psoriasis can be challenging to diagnose and treat, necessitating thorough clinical evaluation and mycological testing. Proactive monitoring and timely intervention are crucial to prevent complications and ensure optimal management outcomes in immunosuppressed individuals with dermatophyte infections.

引言：皮肤癣菌病（dermatophytosis）的环状皮损（annular lesions）与银屑病（psoriasis）的斑块极为相似，给诊断和治疗带来重大挑战。甲氨蝶呤（methotrexate）是银屑病的常用治疗药物，但其免疫抑制作用可能加重皮肤癣菌病。
病例报告：一名患有慢性斑块型银屑病的中年男性，已服用甲氨蝶呤片（每周一次，7.5mg）并外用类固醇一年。尽管病情有所改善，但每当外用类固醇减量时，新的环状皮损就会出现。因病情控制不佳感到沮丧，患者最终前往三级医疗中心就诊，通过皮肤镜检查、真菌学检测和组织病理学检查，确诊其同时患有体癣（tinea corporis）和银屑病。随后停用甲氨蝶呤和类固醇，并开始抗真菌治疗。皮肤癣菌病得到控制后，重新启用甲氨蝶呤，同时针对性地外用类固醇和抗真菌乳膏。
结论：体癣与银屑病并存时，诊断和治疗均具有挑战性，需进行全面的临床评估和真菌学检测。对于患有皮肤癣菌感染的免疫抑制个体，积极监测和及时干预至关重要，以防止并发症并确保最佳管理效果。