Successful response in a case of severe pustular psoriasis after interleukin‐1β inhibition

Summary Generalized pustular psoriasis (GPP) is a severe type of psoriasis accompanied by systemic and often life‐threatening manifestations. The efficacy of the interleukin (IL)‐1 antagonist anakinra in cases of GPP underscores the role of IL‐1 in disease pathogenesis. We present a case of a middle‐aged man who developed an abrupt and severe form of GPP with severe eosinophilia and cholestatic hepatitis. The patient received salvage treatment with a combination of glucocorticoids, hydroxyurea and imatinib, while administration of the IL‐1 inhibitor anakinra resulted in remission of hepatitis and a significant skin improvement. However, due to persistent hypersensitivity skin reactions, anakinra was withdrawn and replaced with the anti‐IL‐1β antagonist canakinumab. As a result of canakinumab, the patient's skin completely cleared, while no systemic manifestations recurred. After 1 year of continuous canakinumab therapy, the patient remained virtually free of symptoms, while the drug was well tolerated. What's already known about this topic? Generalized pustular psoriasis (GPP) is an inflammatory dermatological disorder accompanied by severe systemic complications. Genetic studies and reports of favourable response to IL‐1 blockade strongly implicate the IL‐1 family in the pathophysiology of GPP. What does this study add? This is the first report of a complete and sustained response of GPP to the anti‐IL‐1β monoclonal antibody canakinumab. Randomized control trials with IL‐1 inhibitors in severe pustular and erythodermic psoriasis are encouraged. Linked Comment: Foerster. Br J Dermatol 2017; 176:17–18.