Mepolizumab Therapy for Recalcitrant Eosinophilic Annular Erythema in an Adult: A Case Report and Review of Treatment Options

Abstract Eosinophilic annular erythema (EAE) is a rare condition with a chronic relapsing and remitting course, characterized by the presence of annular or polycyclic erythematous and plaque lesions and prominent tissue eosinophilia on histopathology. There is an ongoing discussion on whether EAE is a subset of Wells syndrome (eosinophilic cellulitis) or a separate entity. To date, few cases of EAE have been reported in the literature; of these, about 40 cases were in adults and fewer than ten cases were in children. Given the rarity of this condition, there are no clear recommendations for its management. Systemic corticosteroids and antimalarials are the most commonly used medications used to treat EAE, but many cases have been reported in the literature that are resistant to treatment with these medications. Here, we present a 65-year-old female with EAE refractory to numerous systemic therapies (corticosteroids, hydroxychloroquine, dapsone, doxycycline, methotrexate) who showed a good response to mepolizumab, a humanized monoclonal antibody that blocks interleukin-5. To the best of our knowledge, this is the first reported case of mepolizumab therapy in a patient with EAE. We also review other treatment strategies that have been used to manage this condition to date. Targeting cytokines crucial for the functioning of eosinophils may be a novel direction in the management of EAE, but prospective, double-blinded and placebo-controlled studies are needed to provide further evidence.