New-onset psoriasis following treatment with the interleukin-1 receptor antagonist anakinra

Abstract

Conflicts of interest: none declared. Sir, Anakinra is a recombinant human form of interleukin‐1 receptor antagonist (IL‐1Ra) that blocks interleukin‐1 (IL‐1) signalling. It is administered as a daily subcutaneous injection, and is used to treat patients with rheumatoid arthritis (RA). The drug is generally well tolerated and has a good safety profile.1 The most common adverse effects are injection site reactions.2 We report a patient with RA who developed psoriasis following anakinra therapy. Recently, other biologic anticytokine drugs, such as all of the tumour necrosis factor (TNF)‐α blocking agents (etanercept, infliximab, adalimumab), have been reported to cause or exacerbate psoriasis.3 However, to our knowledge, no psoriatic lesions have been reported in patients treated with anakinra. A 75‐year‐old woman developed in 1995 a symmetrical polyarthritis involving shoulders, small joints of hands and feet, and knees. The rheumatoid factor was negative. She fulfilled the diagnostic criteria for RA.4 There was no personal or familial history of psoriasis. She had been treated with multiple disease‐modifying antirheumatic drugs, that were discontinued because of side‐effects or lack of efficacy. Despite treatment, her RA was still active and she developed typical erosions in metacarpophalangeal joints. Therefore, she was started on combined therapy with TNF‐α antagonists and methotrexate. Etanercept and infliximab were discontinued because of lack of efficacy, and adalimumab was withdrawn because of an episode of left cardiac failure. In March 2006, anakinra (100 mg daily subcutaneously) was started. In December 2006, 9 months later, she presented with typical psoriatic, scaly, erythematous plaques on the elbows (Fig. 1a). Skin biopsy from the patient’s left elbow showed psoriasiform hyperplasia, parakeratosis and a lymphocytic infiltrate in the upper dermis, consistent with psoriasis (Fig. 1b). Treatment with anakinra was discontinued, and the psoriatic lesions improved significantly with the addition of topical steroids and vitamin D.