Sir, a healthy 45-year-old, right handed male dentist, working in a dental access centre, presented with acute incapacitating pain over the extensor aspect of the right forearm associated with a sausage-shaped swelling. He had had no previous musculoskeletal problems and was not a sportsman. Movement of the thumb was associated with audible and palpable crepitus in the forearm. The condition was treated with steroid injection and rest; it gradually settled to enable the dentist to return to work.

Peritendinitis crepitans, also known as intersection syndrome, is an unusual condition of the forearm. Thought to be inflammatory, it presents with acute pain, crepitation and a sausage-shaped swelling on the lower part of the extensor aspect of the forearm 4-10 cm proximal to Lister's tubercle.1 It has a low incidence and generally settles with conservative treatment, sometimes requiring ultrasound guided steroid injection. Peritendinitis crepitans tends to occur following an increase or change in upper limb activity or after a period of rest.1,2

Dental access centres undertake a large number of surgical procedures, in particular extractions and endodontics, both of which require either gripping or rolling movements with the thumb against the fingers. With limited preventive work in between such surgical procedures, the level of activity of the hand and in particular the thumb during the working day becomes significant.

Upper limb disorders are usually of unknown aetiology but are sometimes thought to be activity related and this is particularly the case with regards to this condition. Nevertheless, given the nature of the role, a dentist would not necessarily be expected to develop a condition that would normally be associated with heavy manual or assembly line work. There are no previous case reports in the literature in the dental profession. Were peritendinitis crepitans a purely work related condition one would have expected cases to have occurred in dentists in clinical practice when extractions were common and education and preventive work not a major feature of the dentist's working day. Furthermore the anatomy of the area where tendons cross muscles with no mechanism of separating and protecting the two conditions suggests that this condition may be triggered by, rather than caused by, work.