Lancing of a boil leading to severe invasive methicillin-sensitive Staphylococcus aureus infection in an adolescent.

A 10-year-old boy presented to the emergency department with chief symptoms of fever and right leg pain for 3 days. Also of note, he reported that he had a boil on his neck 2 weeks prior to admission. This lesion was lanced by his mother with a hot needle. An X-ray, CT scan and MRI of the right knee showed no evidence of osteomyelitis. He was placed on intravenous vancomycin for empiric treatment. Blood culture grew methicillin-susceptible Staphylococcus aureus (MSSA), susceptible to vancomycin and clindamycin. He continued to spike fever with the development of erythema, and swelling of the distal thigh. Repeat MRI of the right knee showed osteomyelitis and subperiosteal abscess in the distal femur shaft with surrounding intramuscular abscesses and pyomyositis. He was taken to the operating room where 50 mL of fluid was drained from the periosteal abscess and a bone biopsy was obtained. Bone marrow culture also grew MSSA, susceptible to clindamycin.