Septic arthritis of the hip caused by Streptococcus pyogenes bloodstream infection in a previously healthy adult: a case report

Abstract

Pyogenic arthritis of the hip joint is a rare but serious complication of invasive Streptococcus pyogenes (group A Streptococcus [GAS]) infection that may rapidly lead to joint destruction and is often difficult to diagnose early. This report describes the case of a previously healthy adult who developed GAS bloodstream infection complicated by unilateral pyogenic arthritis of the hip, temporally following an episode of sore throat. A 37-year-old man presented with right hip swelling, pain, and restricted mobility after a sore throat and high fever. The patient met the Sepsis-3 criteria at presentation. Magnetic resonance imaging, blood culture, and joint fluid culture results confirmed GAS bloodstream infection complicated by unilateral pyogenic arthritis of the hip. Owing to a history of skin allergic reactions to intravenous penicillin and cephalosporins, the patient was treated with intravenous meropenem, combined with ultrasound-guided joint aspiration–lavage. The patient's clinical condition improved progressively, and no recurrence was reported during 10 months of follow-up. GAS bloodstream infection should be considered in the differential diagnosis of previously healthy adults presenting with recurrent fever and new-onset hip pain following pharyngitis. Recurrence of fever after initial defervescence may warrant evaluation for invasive bacterial infection. In patients with β-lactam allergy and documented susceptibility, meropenem may represent an option after individualized assessment. Early image-guided joint drainage, combined with appropriate systemic antimicrobial therapy such as intra-articular infusion, may contribute to infection control and preservation of joint function.