Enteropathic Spondyloarthropathy

Enteric spondyloarthropathy can occur in one of three patterns. One is a peripheral asymmetric arthritis with fewer than five joints involved. Second is a peripheral symmetric polyarthritis with five or more joints involved. And the third pattern is characterized by spinal involvement with sacroiliitis and spondylitis, sometimes with peripheral joint involvement.(28,29)

The peripheral arthritis may precede the diagnosis of inflammatory bowel disease and, once established, often parallels the activity of the inflammatory bowel disease. Spondylitis rarely occurs prior to the diagnosis of inflammatory bowel disease and does not correlate with the disease activity of the underlying bowel disease.

Extra-articular manifestations
Clubbing of fingers, uveitis, erythema nodosum, and pyoderma gangrenosum are also observed in inflammatory bowel disease, with a higher frequency in Crohn disease.(4) Subclinical inflammatory lesions in the gut are common, as observed on colonoscopic mucosal biopsy studies in patients with spondyloarthropathy but no gastrointestinal symptoms. Follow-up studies of such patients indicate that 6% develop inflammatory bowel disease and, of those with inflammatory gut lesions, 15% to 25% develop clinical Crohn disease.(30) This suggests that patients with subclinical inflammatory bowel disease can present with extraintestinal manifestations, making diagnosis more challenging.

Undifferentiated Spondyloarthropathy
"Undifferentiated spondyloarthropathy" represents a working diagnosis for patients who have manifestations consistent with a spondyloarthropathy but who do not meet the criteria for its well-defined forms. At present, it is unclear if these patients have an early, incomplete form of a defined spondyloarthropathy.

A good history and physical examination documenting inflammatory back pain, enthesitis, or dactylitis (Figure 5) should raise the suspicion of a spondyloarthropathy. Often, the passage of time with repeated history and examinations will clarify the nature of any underlying disease.

Figure 5.
Dactylitis involving the left fourth toe in a patient with undifferentiated spondyloarthropathy

Treatment of Spondyloarthropathies
It is difficult to test treatments for the spondyloarthropathies because the disease- especially the spinal involvement-progresses slowly. In the absence of specific treatments, the general goals of therapy are to control symptoms of morning stiffness and pain, to slow or stop disease progression, and to help the patient maintain erect posture and functional ability.

Drug therapy
NSAIDs have been the mainstay of therapy, but they have not been shown to slow or stop disease progression. Cyclooxygenase-2 inhibitors are likely effective and have an improved gastric safety profile compared with nonselective NSAIDs. Nonselective NSAIDs are often avoided in spondyloarthropathy associated with inflammatory bowel disease. NSAIDs are often very beneficial in patients with undifferentiated spondyloarthropathy.(31,32) If patients do not response to NSAIDs, one of the following second-line therapies should be considered.

Sulfasalazine
Sulfasalazine has been shown to be effective for controlling inflammatory symptoms of spondyloarthropathy over the short term, especially peripheral musculoskeletal involvement. (33-35) Sulfasalazine was effective in reducing synovitis in patients with peripheral polyarticular involvement but had no effect on axial involvement.(36) Although sulfasalazine has disease-modifying activity in rheumatoid arthritis, this has not been documented for spondyloarthropathy.(37)

Methotrexate
Methotrexate has been shown to be effective in the treatment of the articular and skin manifestations of psoriatic arthritis.(38) In small studies of patients with ankylosing spondylitis, there was apparent benefit for peripheral but not axial involvement.(39-42)

Corticosteroids
Oral corticosteroids are occasionally used in patients with a spondyloarthropathy who have severe polyarticular symptoms unresponsive to other treatments, especially patients with psoriatic arthritis. Intra-articular injections are used for monoarticular or oligoarticular flares. In our experience, spondyloarthropathy does not respond as well to oral or injected corticosteroids as does rheumatoid arthritis. However, some patients' axial or peripheral arthritis may respond dramatically to a therapeutic course of corticosteroids.

Tumor necrosis factor inhibitors
Infliximab has been used in the treatment of spondyloarthropathies, including ankylosing spondylitis (43,44) and psoriatic arthritis, (45,46) in relatively small studies that showed benefit. Etanercept has been shown to effectively control the articular and cutaneous manifestations of psoriatic arthritis (47,48) and can inhibit radiographic progression as well. (49) A recent double-blind, placebo-controlled trial showed etanercept to be effective in treating the musculoskeletal symptoms of ankylosing spondylitis.(50) Etanercept recently was approved by the US Food and Drug Administration for the treatment of active ankylosing spondylitis.

Other therapies
Physical therapy, especially extension exercises for the spine, is believed to help the patient maintain erect posture. Orthopedic surgery-including total joint arthroplasty of the hips and knees and, in rare cases, corrective spinal surgery-may be beneficial. However, heterotopic bone formation may occur after total joint arthroplasty, especially at the hip joint, and prophylactic treatment should be considered.

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.