Pneumococcal vertebral osteomyelitis and psoas abscess in a patient with systemic lupus erythematosus disclosing positivity of pneumococcal urinary antigen assay.

A 53-year-old woman with systemic lupus erythematosus presented with a 3-day history of fever and coughing. Diagnosis of pneumococcal bronchitis was made based on symptoms and positivity of pneumococcal urinary antigen test. On day 3, severe low back pain acutely occurred. Pneumococcal vertebral osteomyelitis and psoas abscess was diagnosed 17 days later by yield of penicillin-susceptible S. pneumoniae strain in blood cultures and drainage fluid. Although pneumococcal urinary antigen test is a useful tool for the diagnosis of pneumococcal pneumonia, we should consider the possibility of pneumococcal infections other than pneumonia or overwhelming bacteremia in immunosuppressive patients when urinary antigen test is positive.