Tinea Incognito Mimicking Primary Treatment Failure in a Patient with Psoriasis Treated with Guselkumab
Year: 2026
Type: article
Study design: Case Report
Abstract: Biologic agents are widely used for severe psoriasis and are generally safe, but infections may develop or worsen during therapy and mimic disease exacerbation. We report a 24-year-old woman with psoriasis treated with guselkumab who developed sudden, widespread worsening of oozing psoriasiform lesions. Skin biopsy revealed dermatophytosis consistent with tinea incognito. Three weeks of oral and topical antifungal therapy resolved the fungal infection, while residual psoriatic lesions continued to improve with guselkumab. Guselkumab has been continued for 1 year without recurrence or reinfection. Although baseline mycological testing was unavailable, the clinical course indicates that a pre-existing, clinically inapparent dermatophyte infection may have become clinically evident and spread extensively during guselkumab therapy. This case highlights the importance of considering fungal infections in patients receiving biologic therapy who develop atypical psoriasis worsening and supports early mycological evaluation when clinically indicated.
Authors: Seowon Song, Subin Lee, Hoon Kang, Jung Eun Kim
Language: English
Topic: Nail Diseases and Treatments
Subfield: Dermatology
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
OpenAlex ID: W7215040468