Arthritis of leprosy.

An inflammatory polyarthritis has been previously described in leprosy but accounts of the clinical characteristics have varied. All patients with joint symptoms admitted to a leprosy centre over 5 months were examined by a rheumatologist. Of 48 acute admissions, 20 (42%) had a symmetrical polyarthritis affecting the wrists and fingers. This was strikingly similar to RA in appearance. The arthritis occurred exclusively in patients with reactions mainly during anti-mycobacterial treatment. The clinical features of the joint disorder were identical in Type I (associated with alterations in immune status) and Type II (erythema nodosum leprosum) reactions. Synovial tissue from one patient revealed no mycobacteria. Four of five hand X-rays suggested small erosions of the finger joints.