Spondyloarthropathies: Reactive Arthritis and Reiter Syndrome

Diseases such as gonococcal arthritis and inflammatory bowel disease can mimic reactive arthritis and should be excluded before making the diagnosis of reactive arthritis.

Articular manifestations
The most distinctive musculoskeletal manifestation of reactive arthritis is enthesitis, occurring in 70% of patients, most commonly in the heel or knee regions.

In reactive arthritis, the arthritis typically appears within 1 to 4 weeks of infectious exposure. Constitutional symptoms are usually mild, and fever, if present, is low-grade. Joint stiffness and myalgias are prominent early symptoms. The pattern of arthritis is typically an acute, additive, asymmetric oligoarthritis mainly involving the lower extremities.

Axial skeletal involvement including sacroiliitis and spondylitis occurs clinically in about 50% of patients, although radiographic changes are seen in only 20% initially. Occasionally, the upper extremities are involved in an asymmetric fashion, especially the hands and wrists. The knee can become markedly swollen, with inflammatory synovial fluid, popliteal cyst dissection, and rupture. Exuberant calcaneal spurs may eventually develop due to ossification of the tendinous insertions. Dactylitis or sausage digits may occur due to flexor tenosynovitis in the fingers or toes.

Extra-articular manifestations
Urethritis may be a principal feature of reactive arthritis, but genitourinary manifestations can also include cervicitis, salpingitis, vulvovaginitis, aseptic pyuria, and prostatitis. A sterile form of urethritis can be seen after Salmonella and Shigella infection, as well as after urogenital or chlamydial infection.

The precipitating episode of diarrhea is often mild, but occasionally it may be bloody and prolonged. Patients with Yersinia enteritis often have mild, recurrent abdominal complaints.

Small, shallow, painless ulcers of the glans penis and urethral meatus (balanitis circinata) have been described and may precede symptoms of arthritis. In uncircumcised patients, the lesions are moist and are asymptomatic unless secondarily infected. The foreskin has to be retracted during the physical examination to detect these lesions. On the circumcised penis, the lesions harden to a crust, which may scar and cause pain.

Keratoderma blennorrhagica is a hyperkeratotic skin lesion that is seen in 12% to 14% of patients. It begins as clear vesicles on erythematous bases and progresses to macules, papules, and nodules. The lesions are often found on the soles of the feet, but they may also be found on the toes, palms, scrotum, penis, trunk, and scalp. The lesions are indistinguishable clinically and microscopically from pustular psoriasis. Onycholysis may occur.

Superficial oral ulcers are an early and transient feature of the disease. Erythema nodosum is a feature of Yersinia enteritis, and can mimic inflammatory bowel disease.

Conjunctivitis is the most common ocular complication of reactive arthritis. It occurs in the majority of patients with Shigella infections and is often the initial symptom. It also occurs after Salmonella and Campylobacter infections. About 35% of patients with postvenereal reactive arthritis develop conjunctivitis. Uveitis may occur as an independent, asynchronous event due to the shared genetic susceptibility related to the B27 antigen.

Cardiac complications are reported as late sequelae in 10% of patients with severe, longstanding disease including conduction abnormalities and aortic regurgitation. Conduction disturbances range from a prolonged PR interval to complete heart block.(24)

Laboratory evaluation
The infection triggering the reactive arthritis should be sought and treated as warranted. Often, however, the local infection has resolved by the time features of reactive arthritis have developed. Prolonged antibiotic treatment courses have not been shown to reliably influence the course of the arthritis.

Radiographic evaluation
The characteristic radiographic feature is not joint erosion, as in rheumatoid arthritis, but reactive new bone formation at sites of enthesitis (Figure 4). The presence of bony proliferation as seen in reactive arthritis, psoriatic arthritis, and ankylosing spondylitis is the most helpful radiographic feature in distinguishing these diseases from rheumatoid arthritis. Linear periostitis along the metacarpal, metatarsal, and phalangeal shafts, and exuberant periosteal spurs with indistinct margins can be seen along the sites of tendinous insertion onto bone.

Figure 4.
Radiograph of the heel in a patient with Reiter syndrome, showing lesions
secondary to enthesitis including erosions (insertion of the Achilles tendon
on the calcaneus) and periosteal new bone formation
(insertion of the plantar fascia on the calcaneus) (arrow).

In the spine, asymmetric, paravertebral, comma-shaped ossification is a characteristic finding on plain radiography in reactive arthritis and psoriatic arthritis. It typically involves the lower three thoracic and upper three lumbar vertebrae. In contrast to ankylosing spondylitis, squaring of the vertebrae is uncommon. Plain radiographs of the spine are abnormal in up to 70% of cases of chronic reactive arthritis.

Cleveland Clinic Journal of Medicine
Volume 71, Number 3, March 2004

This paper discusses therapies that are experimental or are not approved by the U.S. Food and Drug Administration for use under discussion.