Microscopic examination showed acanthosis, mild spongiosis, and parakeratosis of the epidermis and focal collections of polymorphic leukocytes within the stratum corneum. A superficial and deep perivascular infiltrate was present, composed predominantly of eosinophils, admixed with lymphocytes and histiocytes. No vasculitis or parasites were present, and a methenamine silver stain was negative for fungi. These findings were diagnostic of eosinophilic cellulitis.
Oral prednisone therapy was initiated at a dosage of 40 mg/d. The patient's symptoms began to resolve rapidly, and he was discharged the following day on a tapering regimen of oral prednisone.