Severe complicated mastoiditis caused by nontypable Haemophilus influenzae

Non-typable Haemophilus influenzae (NTHi) is emerging as an important cause of invasive disease in immunized children. We describe a healthy, fully immunized 4-year old child who presented with bacteremia due to NTHi without overt acute otitis media (AOM), and subsequently developed severe mastoiditis complicated by sigmoid sinus thrombosis. Although, mastoiditis is typically regarded as a complication of AOM, those cases without antecedent AOM may represent an entirely different pathophysiological process with NTHi bacteremia seeding the mastoid. We present another example of the potential invasiveness of NTHi with a temporal sequence of events whereby NTHi bacteremia seeds the mastoid. This may represent novel sequelae of NTHi infection.