A case of Sweet's syndrome (acute febrile neutrophilic dermatosis) occurring concurrently with bullous pyoderma gangrenosum is reported to emphasize the close relationship between these two disorders. Atypical pyoderma gangrenosum and Sweet's syndrome have been described as occurring simultaneously in haematological dyscrasias but not, to our knowledge, in ulcerative colitis. It has been proposed that pyoderma gangrenosum, Sweet's syndrome, erythema elevatum diutinum and subcorneal pustular dermatosis may represent manifestations along a continuum of neutrophilic dermatoses.