[A case of pediatric recurrent acute mastoiditis caused by penicillin-resistant Streptococcus pneumonia complicated by primary immunodeficiency].

Penicillin-resistant Streptococcus pneumoniae (PRSP) is a frequently detected pathogen of intractable acute otitis media and is associated with prolonged or recurrent infection. The use of antibiotics has made the incidence of secondary acute mastoiditis following acute otitis media relatively rare, but when it does occur, its severe complications may be life-threatening. We report a case of pediatric recurrent acute mastoiditis caused by PRSP in a 6-year-old boy suffering from PRSP acute mastoiditis on 4 occasions, twice undergoing simple mastoidectomy. Although we initially suspected PRSP to be the chief factor in iterative infection, immunological analysis demonstrated significantly decreased IgG and IgA antibodies in serum and the patient was diagnosed as having common variable immunodeficiency (CVID). As the first middle ear infection occurred at the age of 6 and there was no history of upper respiratory tract infection, CVID may be the main pathological factor of recurrent mastoiditis, although infection occurred, only in the ear and did not involve other organs. This suggests that recurrent mastoiditis in the present case involved the coexistence of PRSP and CVID.