Muscle loss following a single high-dose intramuscular injection of corticosteroids to treat disease flare in patients with rheumatoid arthritis.

Objective: Adverse changes in body composition, specifically decreased muscle mass (MM) and increased fat mass, characterize rheumatoid arthritis (RA). These changes, termed rheumatoid cachexia (RC), are important contributors to the disability and elevated co-morbidity risk of RA. Recently, we observed substantial muscle loss (~2 kg) in a patient with RA following a single intramuscular (IM) corticosteroid (CS) injection to treat a disease flare.