A 42-year-old woman was observed during 3 bouts of eosinophilic cellulitis over a 6-year-period. Skin biopsies were taken at each relapse and processed for histological, immunofluorescent and ultrastructural studies. Histologically the eosinophilic infiltrate extended to the deep dermis and the subcutaneous fat. High levels of circulating immune complexes, and complement and IgG deposits around the vessels were detected for as long as the cutaneous lesions lasted. Under the electron microscope eosinophils were numerous, half of them degranulated and some granules had a double cristal core. No injury to the vessel walls was observed. The 3 recurrences occurred respectively after lincomycin, nesdonal, acetyl salicylic acid and pholcodin ingestion and responded to sulfone and steroid therapy.