Sweet's syndrome: a clinicopathologic review of twenty-nine cases. Twenty-nine patients with Sweet's syndrome were studied. Not all of Sweet's original criteria were necessarily present and diagnosis was dependent on the recognition of the typical, acute, tender, erythematous plaques and the characteristic histologic features of a neutrophilic infiltrate with leukocytoclasis. Women are affected much more frequently than men. The origin of Sweet's syndrome is still unclear, but an underlying disease was found in more than 50% of our cases. A streptococcal infection was evident in six cases, inflammatory bowel disease in three cases, malignancy in four cases, and pregnancy in two others. Treatment with oral prednisolone for an average of 6 weeks was the usual treatment, although in four patients the disease cleared spontaneously. Resolution of the eruption is occasionally followed by milia and scarring. Recurrences are common and affect up to one third of patients. 