M65: Synovitis and tenosynovitis

M65.0: Abscess of tendon sheath

Abscess of tendon sheath, designated as M65.0 in the ICD-10 WHO 2016 classification, is a localized accumulation of pus within the protective layer surrounding a tendon, known as the tendon sheath. This condition often results from an infection that could stem from an injury, a foreign object entering the body, or even an untreated bacterial infection elsewhere in the body spreading to the tendon sheath. Common symptoms include redness, swelling, pain, and warmth in the affected area, and a general feeling of being unwell. Over time, without proper medical intervention, the abscess can increase in size, potentially limiting movement and causing severe discomfort. This condition most frequently impacts the hands and feet but can occur in any tendon sheath throughout the body.