Etymologically a ténosynovites means inflammation of a tendon sheath. We recognize two separate presentations: exsudative and stenosing. The wide differential diagnosis includes infections, most of chronic inflammatory joint diseases, mainly connective tissue disorders, rheumatoid and psoriatic arthritis, pathology related to mechanical stress as De Quervain's tenosynovitis or trigger finger and unusually tumor. Diabetes is a risk factor for most of them and is related to poor prognosis. Musculoskeletal ultrasound is useful for diagnosis and to guide procedure as fluid aspiration or steroid injection.