Psoriasis and Psoriasiform Eruptions Reported During Targeted Treatment for Atopic Dermatitis: A Review of Clinical Phenotypes, Proposed Immunologic Mechanisms, and Management

Atopic dermatitis (AD) and psoriasis are chronic inflammatory skin diseases with distinct but partly overlapping immune pathways. Psoriasis and psoriasiform eruptions have been reported during targeted treatment for AD, most frequently with dupilumab, which inhibits interleukin (IL)-4 and IL-13 signalling. This narrative review examines the reported clinical phenotypes, timing, proposed immunological mechanisms, diagnostic uncertainties and management approaches. The reviewed literature also includes psoriasis-like eruptions during treatment with tralokinumab, lebrikizumab and nemolizumab, although the supporting evidence for these agents remains limited. Presentations range from localised scaly plaques to extensive, pustular or erythrodermic eruptions, sometimes following improvement in the underlying AD. A relative increase in IL-23/T-helper 17 activity after attenuation of type 2 signalling, potentially accompanied by IL-36-associated inflammation in some lesions, has been proposed as a mechanism. However, temporal associations and limited tissue findings do not establish drug causality. Most available evidence derives from case reports, case series and observational studies, with heterogeneous diagnostic criteria and inconsistent follow-up. Consequently, the incidence, comparative risk and optimal treatment of these eruptions remain uncertain. Clinical assessment should distinguish confirmed psoriasis from psoriasiform dermatitis and consider alternative triggers, prior psoriasis and coexisting eczema. Management should balance eruption severity against AD control, with treatment continuation, adjunctive therapy or switching considered individually. Prospective studies using consistent definitions and reporting outcomes for both conditions are needed.