Foreign body granuloma. A cause of trigger thumb.

Snapping or triggering of fingers is a common complaint, the most frequent cause being tenosynovitis of the flexor tendon sheath. Injury of the flexor tendon as a precursor of triggering is infrequent. Foreign body granuloma of the tendon sheath as an antecedent factor has not been yet recorded. We report a case of stenosing tenosynovitis of the flexor tendon of the thumb caused by local reaction to a foreign body.