The use of biologic therapies for the treatment of chronic plaque psoriasis has been linked to the development of atopic eczema, amongst other cutaneous adverse events. This can cause diagnostic confusion and create difficulty in the management of patients with plaque psoriasis. The main objective of this systematic review was to review all cases of eczema, including atopic eczema, reported in patients treated with biologics for chronic plaque psoriasis. PubMed, Medline and Embase databases were used to identify studies reporting eczema in patients treated with biologic therapy for chronic plaque psoriasis. A total of 92 patients were identified from 24 studies, with patients treated with either: adalimumab; etanercept; infliximab; ixekizumab; secukinumab; or ustekinumab. Factors common to some reported cases include: a prior history of atopy; eosinophilia; raised serum immunoglobulin E. Twenty‐three had documented treatment outcomes; 14 had biologic therapy discontinued or switched. Management strategies included topical or oral corticosteroids, and treatment with alternative systemic agents such as ciclosporin or apremilast. This adverse event occurred in 1.0–12.1% of patients within trial data and observational studies. This review demonstrates that there are consistent reports of a switch to an atopic eczema phenotype from psoriasis in patients taking biologics inhibiting tumour necrosis factor alpha and the interleukin (IL)‐17/IL‐23 axis. The majority stopped the implicated biologic, but conservative management was successful in some cases. Those with an atopic diathesis may be more at risk. Elucidation of mechanisms and risk factors would contribute to optimal therapy selection for individual patients.

Brodalumab is a recombinant, fully human monoclonal antibody (IgG2) which binds with high affinity to the interleukin (IL) 17 receptor A (IL17R). Brodalumab is now licensed and approved for the treatment of moderate-to-severe chronic plaque psoriasis in North America and Europe. As the third to market in the class of agents targeting IL-17, we review its place in the expanding armamentarium of cytokine-directed therapies for patients with severe psoriasis. Brodalumab is a highly efficacious therapy for psoriasis, whose mechanism of action is separate from other treatments targeting IL-17. Its use is associated with rapid control of the disease. We suggest that brodalumab is likely to be considered in those patients requiring rapid control of disease, where there is no known history of depression or suicidal ideation.

Methotrexate continues to be one of the most widely used systemic immunosuppressive agents in dermatology. In addition to the important, well-characterized adverse effects such as hepatotoxicity and myelosuppression, methotrexate may induce a number of rare cutaneous adverse events including methotrexate-induced ulceration. We present a case of methotrexate-induced cutaneous ulceration in a patient with chronic plaque psoriasis occurring during long-standing methotrexate therapy. Withdrawal of the drug and appropriate skin care led to rapid healing of the ulceration and the agent was later safely reintroduced for the ongoing management of the patient’s chronic plaque psoriasis. Review of the literature demonstrates cases of this important rare adverse event, primarily occurring in patients with chronic plaque psoriasis, induced by triggers such as accidental overdose or introduction of an interacting agent. Cutaneous ulceration typically precedes other markers of toxicity. Active treatment with folinic acid (calcium leucovorin) may be required. Early recognition, prompt cessation of methotrexate, and appropriate treatment minimizes morbidity. Dermatologists need to be alert to the possibility of cutaneous adverse events associated with methotrexate therapy, aware of potential drug interactions, and confident in the management of methotrexate toxicity.Electronic supplementary materialThe online version of this article (doi:10.1007/s13555-014-0056-z) contains supplementary material, which is available to authorized users.