Rheumatoid subcutaneous bursitis.

We reviewed 11 patients with rheumatoid subcutaneous bursitis involving the olecranon bursa in 10 and an adventitious bursa in 1. All patients had a positive latex fixation test for rheumatoid factors. The mean bursal fluid white blood count (WBC) was 2,924/mm3 compared with a mean joint fluid WBC of 15,608/mm3 in 32 consecutive cases of classical or definite rheumatoid arthritis (p less than 0.001). Bursal fluid glucose and complement concentrations were low. Cholesterol crystals were present in 5 of 6 nodular bursae, and in none of the 5 non-nodular bursae (p less than 0.05). Two patients had acicular cholesterol crystals that had previously led to an erroneous diagnosis of gout.