[Myeloproliferative syndrome and acute febrile neutrophilic dermatosis (Sweet's syndrome)--a rare association].

The case is reported of a 73-year-old man presenting with a history arthralgia, conjunctivitis, fever and typical lesions of acute febrile neutrophilic dermatosis (Sweet's syndrome). Due to massive leukocytosis, an unclassifiable myeloproliferative disorder was later diagnosed. The disease responded well to hydroxyurea but only partly to steroids. The case demonstrates the necessity of close hematologic follow-up in Sweet's syndrome, since some 10% of patients develop hematologic malignancies weeks or months later.