(See also Overview and Evaluation of Hand Disorders.)
The usual cause of infectious flexor tenosynovitis is a penetration and bacterial inoculation of the sheath.
Infectious flexor tenosynovitis causes Kanavel signs:
X-rays should be taken to detect occult foreign bodies. Acute calcific tendinitis and rheumatoid arthritis can restrict motion and cause pain in the tendon sheath but can usually be differentiated from infectious flexor tenosynovitis by a more gradual onset and the absence of some Kanavel signs. Disseminated gonococcal infection can cause tenosynovitis but often involves multiple joints (particularly those of the wrists, fingers, ankles, and toes), and patients often have recent fever, rash, polyarthralgias, and often risk factors for a sexually transmitted disease. Infection of the tendon sheath may involve nontuberculous mycobacteria, but these infections are usually more indolent, especially in patients receiving immunosuppressive therapy.
Treatment of infectious flexor tenosynovitis is surgical drainage (eg, irrigation of the tendon sheath by inserting a cannula into one end and allowing the irrigating fluid to pass along the tendon sheath to the other end, or an extensive open incision for more serious infections).
Antibiotic therapy (beginning empirically with a cephalosporin) and cultures are also required. In areas where methicillin-resistant Staphylococcus aureus (MRSA) is prevalent, trimethoprim/sulfamethoxazole, clindamycin, doxycycline, or linezolid should be used instead of a cephalosporin.