Complications of local corticosteroid injections.

Unusual complications associated with local microcrystalline corticosteroid injections were observed in four patients with diverse rheumatic disorders. Adverse reactions included (1) bilateral digital flexor tendon rupture following carpal tunnel injection for idiopathic median nerve compression syndrome; (2) bowstring deformity of a finger after local corticosteroid treatment of psoriatic digital flexor tendonitis; (3) carpal tunnel infection following dorsal arthrocentesis of a wrist in a patient with rheumatoid arthritis; and (4) pronounced flushing of the face, neck, and chest after intrasynovial corticosteroid injection in a patient with psoriasis and arthritis. This article considers some physiologic actions of corticosteroids possibly responsible for development of these untoward effects.