Infectious tenosynovitis

What it is

Tenosynovitis is inflammation of a tendon, that is tendinitis, together with its synovial sheath, that is synovitis. The tendons of the hand and wrist, and of the fingers, are the ones most commonly affected. Infectious tenosynovitis is the form caused by infection rather than by overuse.

Causes and risk

Non-infectious tenosynovitis is the most common form, from overuse tendinitis with repetitive use of the tendon in texting, typing or gaming, or from systemic diseases such as rheumatoid arthritis, sarcoidosis and diabetes mellitus.

Infectious tenosynovitis arises in two ways:

• Direct inoculation following penetrating trauma: animal or human bites, IV drug use, thorn prick injuries
• Hematogenous spread of infection: Neisseria gonorrhoeae, Mycobacterium tuberculosis

How it presents

The first sign is pain on passive extension of the affected tendon, with the affected fingers held slightly flexed at rest. Swelling and palpable crepitation follow. Fever and erythema appear when the infection is bacterial, and they are what separate the infectious form. Late signs are tenderness along the affected tendon and a sharp, stabbing pain worsened by activity, followed by a constant dull ache at rest. Edema of the tendons and pain along the tendon course on stretching of the tendon are also described.