Tinea incognita misdiagnosed as rosacea and eczema of the face

Abstract

Introduction Tinea incognita is a dermatophyte skin infection with atypical clinical presentation modified using previous topical immunosuppressive therapy.

Case outline We present a 59-year-old female patient with a pruritic rash on her face. Over three months, she was misdiagnosed with rosacea, contact dermatitis, and atopic dermatitis, and treated with various topical steroids, metronidazole cream, oral antihistamines, dexamethasone, and methylprednisolone. At the first examination in our clinic, she had a pruritic widespread erythema, papules, and plaques on the face, eyelids, and neck, and a few plaques on the chest and extremities (covered with a thick layer of corticosteroid ointment), resembling various skin conditions. Two days after the exclusion of topical treatment, sharply demarcated erythematous lesions with raised scaly edges and numerous pustules appeared. Fungal culture was positive for Trichophyton mentagrophytes var. granulosum. A skin biopsy confirmed dermatophyte fungal infection, and the lesions resolved after systemic and topical antifungal therapy.

Conclusion We present the case of an unrecognized fungal infection of the skin to highlight the importance of a simple laboratory examination of fungal smears and culture before prescribing topical steroids and other immunosuppressive agents in order to avoid misdiagnosis and inappropriate treatment of patients in the future.

Keywords: tinea incognita; tinea atypica; Trichophyton mentagrophytes; topical immunosuppressive therapy