Mastoid subperiosteal abscess.

Subperiosteal abscess was the indication for surgery in every child with acute mastoiditis who underwent mastoidectomy at our institution since 1972. Nineteen such patients are discussed herein. Positive bacteriologic findings included Streptococcus pyogenes in three patients, Streptococcus pneumoniae in three patients, Mycobacterium tuberculosis in two patients, and enterococcus in the one patient with cholesteatoma. Cultures were more often positive for causative bacteria when taken directly from the abscess before or shortly after beginning antibiotic therapy.