Rare case of extensive streptococcal myositis

A rare case of extensive streptococcal myositis is reported. A 46-year-old man was admitted following acute swollen right elbow joint associated with localised pain, erythema and hypoaesthesia. Multiple tense blisters subsequently developed around the affected elbow joint extending to the axilla. He was treated for suspected soft tissue infection and septic arthritis. Blood test investigations demonstrated raised creatine kinase (894 U/L) and inflammatory markers (white cell count 21.1×10⁹/L; C reactive protein 370 mg/L). Emergency CT scan reported extensive myositis affecting the triceps, latissimus dorsi and pectoralis major muscle with no fascial involvement. He was escalated to intensive care unit and treated for infectious myositis. Further investigation revealed positive streptococcal antibody (anti-streptodornase B titre >1600 U/mL). He was managed conservatively with microbiologist specialist input and supportive care. The patient made good recovery after receiving 10 days of intravenous antibiotics and subsequently switched to oral antibiotics. He was discharged on day 30 of admission after receiving intensive inpatient physiotherapy.