Classical rheumatoid arthritis in a patient with Reiter's syndrome

A 44 year old white male presented with sterile urethritis, anterior uveitis, painless oral ulcers, low back pain, and synovitis of the knees and left ankle. Unilateral sacroiliitis and limited spondylitis further supported a diagnosis of Reiter's syndrome. Serum rheumatoid factor was present. The patient subsequently developed morning stiffness, symmetrical polyarthritis of the hands and wrists, and an olecranon subcutaneous nodule. Histology of the nodule and synovium was consistent with rheumatoid arthritis. Histocompatibility antigen typing established the presence of HLA B27. The occurrence of rheumatoid arthritis and Reiter's syndrome in the same patient is quite rare, and the infrequent co-existence of these two inflammatory rheumatic diseases is discussed.