Refractory Chronic Eosinophilic Annular Erythema Successfully Treated with Dupilumab: A Case Report

Eosinophilic annular erythema (EAE) is a rare eosinophilic skin condition that lacks a well-established treatment plan. It is characterized by annular, erythematous, indurated plaques which may be asymptomatic or pruritic. Histologically, EAE shares features with Wells syndrome (WS), including a dense dermal eosinophilic infiltrate, which has led to varying opinions as to whether they are distinct entities or lie on a clinical spectrum. We report a case of a woman with a well-documented 26-year history of refractory EAE that ultimately responded to dupilumab, a monoclonal antibody targeting interleukin-4 and interleukin-13.

The patient initially presented at age 13 with a pruritic eruption composed of arcuate plaques with raised borders, trailing scale, and prominent post-inflammatory hyperpigmentation involving the trunk and extremities. Skin biopsies performed in 2000, 2004, and 2021 demonstrated a superficial and deep perivascular and interstitial eosinophilic infiltrate. The first two biopsies showed eosinophil degranulation and flame figures, while the third remained consistent with EAE without flame figures. Laboratory evaluation revealed persistent peripheral eosinophilia (14-22%) without identifiable underlying systemic disease. Over 26 years of follow-up by a single clinician, the patient failed numerous therapies, including topical and systemic corticosteroids, calcineurin inhibitors, antihistamines, antibiotics, antifungals, imiquimod, dapsone, hydroxychloroquine, phototherapy, upadacitinib, and omalizumab, with only transient or minimal benefit. In July 2025, treatment with dupilumab was initiated using a 600 mg loading dose followed by 300 mg every other week. The patient experienced significant improvement in pruritus and marked reduction in erythema and induration of active lesions, with no new lesions developing over 9 months of follow-up.

This case represents successful treatment with dupilumab of longstanding EAE with overlapping histologic features of WS and persistent eosinophilia and adds to the growing evidence that EAE and WS may lie on a clinical spectrum. The patient's response supports a role for IL-4/IL-13-mediated type 2 inflammation in the pathogenesis of EAE and further suggests that dupilumab may be an effective therapeutic option for refractory, chronic EAE.