Cutaneous complications following extra-articular corticosteroid injections: A prospective cohort study.

BackgroundLocal corticosteroid injections are widely used in the management of musculoskeletal conditions; however, the incidence and timeline of associated cutaneous complications, such as hypopigmentation and subcutaneous fat atrophy, remain poorly defined.ObjectiveTo prospectively evaluate the incidence, timing, and recovery of hypopigmentation and subcutaneous fat atrophy following corticosteroid injections into the dorsal wrist and elbow regions, and to assess the influence of sex, age, and skin shade on these outcomes.MethodsDemographic data were collected, and patients were followed up monthly for 1 year. Patients with positive skin reactions were followed up for up to 18 months.ResultsA total of 45 injection cases were analyzed. After adjustment for potential confounders, hypopigmentation showed attenuated associations with injection region (adjusted odds ratio (OR) =  3.53, 95% confidence interval: 0.34-83.18) and sex (adjusted OR ≈ 0). Unadjusted findings indicated that hypopigmentation was initially more frequent after wrist injections compared to elbow injections and occurred only in women, but these effects diminished after adjustment. Subcutaneous fat atrophy occurred in three (6.7%) cases, all in women. Hypopigmentation developed 4-10 weeks after injection and fully resolved (mean 7.14 months, range 2-18), whereas two of three cases of fat atrophy showed incomplete recovery (P = 0.016 for recovery difference).ConclusionAfter adjustment for potential confounders, hypopigmentation was attenuated but remained more common following wrist injections and in women, while subcutaneous fat atrophy remained rare, with incomplete recovery in some cases. This study provides the first detailed timeline of onset and resolution for corticosteroid-induced hypopigmentation and fat atrophy, highlighting important patterns by injection site and sex, and offering guidance for clinicians in patient counseling and management.