Eosinophilic annular erythema: A late but complete response to hydroxychloroquine

A 69-year-old woman with a 12-month history of asymptomatic erythematous, non-scaly, annular and arciform plaques on her face, trunk and extremities is presented. The skin lesions had been unresponsive to treatment with systemic corticosteroids and antihistamines. Skin biopsy demonstrated superficial and deep dermal inflammatory infiltration consisting mainly of eosinophils and a few neutrophils. Dermal interstitial mucin deposition was also detected in the absence of vasculitis, flame figures or granulomatous reaction. The patient was diagnosed as having eosinophilic annular erythema and treated with hydroxychloroquine (2 × 200 mg/day, p.o.). Response to treatment was observed after 7 weeks and full recovery was achieved after 10 weeks. Eosinophilic annular erythema is rarely reported in the literature. Although hydroxychloroquine is a good choice for treatment, response time can vary between patients.