Terbinafine-induced generalized pustular psoriasis treated with dapsone

Matilde Monteiro, Department of Dermatology, Unidade Local de Saúde de Gaia/Espinho, EPE, Porto, Portugal Joana F. Matos, Department of Dermatology, Unidade Local de Saúde de Gaia/Espinho, EPE, Porto, Portugal André Coelho, Department of Pathological Anatomy. Centro Hospitalar Universitário de Santo António, Porto, Portugal Catarina Queirós, Serviço de Dermatologia, Hospital de Santa Maria, Centro Hospitalar e Universitário de Lisboa Norte, Lisbon, Portugal

We report the case of a 37-year-old healthy woman who developed a generalized cutaneous eruption 1 week after starting oral terbinafine. The eruption was nonspecific, composed of erythematous—violaceous patches, limited areas of epidermal detachment, and sparse sterile pustules. Initial differential diagnoses included Stevens—Johnson Syndrome (SJS) and Acute Generalized Exanthematous Pustulosis (AGEP). Systemic corticosteroid therapy was initiated, with no improvement after 2 weeks. Skin biopsies suggested a diagnosis of pustular psoriasis,and during hospitalization, the patient developed scalyplaques on her scalp, more in keeping with terbinafine-induced Generalized Pustular Psoriasis (GPP). The patient was started on cyclosporine, which proved ineffective, followed by oral dapsone, which led toa major improvement within just 2 days. This case highlights the difficulty of differentiating between SJS, AGEP, and GPP in the presence of a nonspecific drug eruption and suggests dapsone as a safe therapeutic alternative for GPP.

Keywords: Generalized pustular psoriasis. Drug eruption. Terbinafine. Dapsone.