A 26-year-old man presented with a history of intermittent erythematous plaques on his hands and legs. A peripheral blood eosinophilia was noted. Histopathologic examination showed numerous eosinophils and characteristic flame figures. The clinical presentation and histopathologic alterations are consistent with the diagnosis of Wells' syndrome, which is also known as eosinophilic cellulitis. Wells' syndrome is a rare condition of unclear etiology. We discuss its diagnosis and possible association with other conditions that manifest peripheral eosinophilia.