Paradoxical eczema in patients with psoriasis receiving biologics: a case series.

Atopic eczema and psoriasis are chronic, inflammatory dermatoses that can significantly affect the quality of life of those affected. Although both diseases are common, they rarely occur together. Severe psoriasis can be treated with biologic therapies targeting specific cytokine pathways involved in disease pathogenesis. There are reports of paradoxical eczema developing in biologic-treated patients with psoriasis, sometimes necessitating treatment discontinuation and thus leading to poor disease control. This retrospective case series identified 36 such events occurring in 23 patients. All currently available biologic classes were implicated. Eosinophilia (n = 19) and elevated serum IgE (n = 3) were identified in some cases. Treatment strategies included no treatment, topical corticosteroids, broad-acting systemic agents, and discontinuation or switch of biologic therapy. Two patients had persistent eczema and psoriasis despite discontinuation of all biologic therapies.