Sweet's syndrome-like blastomycosis.

Cutaneous North American blastomycosis is characterized clinically by verrucous nodules and histologically by pseudoepitheliomatous hyperplasia, intraepidermal neutrophilic microabscesses, and a dermal mixed inflammatory cell infiltrate containing giant cells. We describe a patient who presented clinically with erythematous nodules and plaques on the lower extremities characterized histologically by a diffuse neutrophilic infiltrate, with lack of epidermal hyperplasia. The lesions were clinically and histologically reminiscent of Sweets syndrome. On close microscopic inspection scattered histiocytes and multinucleated giant cells were present in the dermis, and fungal stains demonstrated budding yeast forms consistent with Blastomyces sp.