Pseudoseptic arthritis after accidental intra-articular deposition of the pneumococcal polyvalent vaccine: a case report

The gram stain showed no organisms. Because the joint aspirate revealed a mixed picture, with the cell count and differential suggestive of a bacterial infection and the glucose and protein suggestive of an aseptic arthritis, the patient was started on clindamycin pending culture results. The differential diagnosis of septic arthritis is long but generally includes crystal-induced arthritis (gout and pseudogout), rheumatoid arthritis exacerbation, viral arthritis, Lyme disease, reactive arthritis (eg, Reiter syndrome, psoriatic arthritis, systemic lupus erythematosus), and, of course, pseudoseptic arthritis. Another contributing factor is this patient's history of a chronic rotator cuff tear and biceps tendon rupture, which more than likely provided inadequate protection of the glenohumeral joint and further facilitated the intra-articular deposition of the PPV injection.