Cranial aseptic osteomyelitis associated with pyoderma gangrenosum.

Neutrophilic dermatoses include a heterogeneous group of entities. Uncommonly, they can accumulate aseptic neutrophilic abscesses in other tissues in addition to the skin. A 34-year-old female complained of a headache which was unresponsive to usual drugs. A TAC revealed an osteolytic lesion in the right parietal bone. The biopsy showed osteomyelitis. One year later, pyoderma gangrenosum appeared in the anterior aspect of both legs. The headache and the cutaneous lesions disappeared after treatment with oral prednisone. The bone involvement in the background of neutrophilic dermatoses is exceptional. Usually, it involves children in the context of chronic recurrent multiple osteomyelitis (CRMO). Only two cases have been described in adults. One of them was a 26-year-old woman who had had CRMO since childhood, and the other one in contiguity with the cutaneous lesions of pyoderma gangrenosum.