Development of Retroperitoneal Abscess Following Routine Injection of Triamcinolone for Musculoskeletal Pain

Glucocorticoid intramuscular injections are a quick, routine procedure done in an outpatient setting to relieve musculoskeletal pain quickly. However, despite being a low-risk procedure it can lead to local infections, including abscess and skin necrosis, and even more rarely, bacteraemia and multi-organ failure. In this case, we present a healthy, immunocompetent woman in her 40s diagnosed with a retroperitoneal abscess due to methicillin-resistant Staphylococcus aureus after an intramuscular injection of triamcinolone. LEARNING POINTS: Injections of glucocorticoids are commonly used in medical practice to alleviate musculoskeletal pain in addition to oral non-steroidal anti-inflammatory agents. Complications of injections include abscess formation, skin necrosis and sepsis, typically from Staphylococcus aureus or other skin colonisers. It should be understood that there are risks associated with injections regardless of age or co-morbidities, so these risks should be discussed with the patient in depth before administration.