Neutrophilic dermatosis-associated sterile chronic multifocal osteomyelitis in pediatric patients: case report and review.

Atypical pyoderma gangrenosum (PG) and Sweet syndrome are neutrophilic dermatoses that share some common features. Sterile chronic recurrent multifocal osteomyelitis is a rare association of these neutrophilic dermatoses that has only been reported in children. We report a 3-year-old girl who initially presented with pain in her left hand and right leg. Roentgenograms and bone scan revealed findings of multifocal osteomyelitis affecting both femurs, the right tibia, left clavicle, right eighth costochondral junction, and left ulna. She was treated with antibiotics without improvement. Bone biopsy of the left ulna revealed histologic changes consistent with osteomyelitis, however, all cultures for bacteria, mycobacteria, and fungi were negative. She subsequently developed an ulcer surrounded by a violaceous, undermined border at the site of the bone biopsy, which also did not improve during antibiotic treatment. A biopsy specimen from this lesion demonstrated a dense perivascular and periappendageal infiltrate of neutrophils within the dermis and edema of the papillary dermis compatible with a neutrophilic dermatosis. She was treated with oral prednisone which resulted in resolution of skin lesions, bone pain, and soft tissue swelling. This case further documents the association between PG or Sweet syndrome and multifocal sterile osteomyelitis.