Enteropathic ArthritisDz

Synonyms: Inflammatory bowel disease–associated arthritis, Crohn’s arthri- tis (also see Whipple’s disease [p. 312] or intestinal-bypass syndrome [p. 221]).

ICD-9 Code: Arthritis associated with inflammatory bowel disease, 713.1; Crohn’s enteritis, 555.9; Ulcerative colitis, 556.9.

Definition: Enteropathic arthritis refers to the inflammatory arthritis seen with Crohn’s disease or ulcerative colitis. It is the most common extraintestinal finding and occurs in 5% to 20% of patients. In both, clinical and histologic gut inflammation, altered intestinal permeability, and the onset of an inflammatory peripheral or axial arthritis may be seen.

Etiology: There is no association between HLA-B27 and colitic peripheral arthritis. However, HLA-B27 is found in 50% of patients with spondylitic colitis. Thus, in the presence of HLA-B27-negative AS, enteropathic arthritis should be considered.

Pathology: GI manifestations and pathology may be insidious or subclinical. In ulcerative colitis, mucosal lesions appear in the colon as ulceration, edema, friability, or microabscesses. In Crohn’s disease, lesions may be present anywhere in the GI tract, although the terminal ileum and colon are most common. Lesions may be ulcerative (aphthoid), patchy, or transmural, with evidence of granulomas. Synovial biopsy reveals chronic, nonspecific inflammatory changes.

Demographics: Peripheral arthritis affects men and women equally. All age groups are affected. Although the onset of arthritis follows established intestinal inflammation in adults, the converse may be seen in children. In contrast with peripheral arthritis, axial disease is more common in men and may precede the onset of colitis.

Cardinal Findings: Triad features of Crohn’s disease includes abdominal pain, weight loss, and diarrhea. Ulcerative colitis is characterized by diarrhea and intestinal blood loss. Disease onset is sometimes heralded by low- grade fever, painful oral (aphthous) ulcers, or ocular (conjunctivitis, anterior uveitis) or cutaneous manifestations (erythema nodosum, pyoderma gangrenosum). In most, GI manifestations antedate or coincide with the onset of arthritis.
Axial arthritis occurs in 10% to 15% of patients with inflammatory bowel disease and is clinically and radiographically indistinguishable from AS. Chronic low back pain/stiffness and limited range of motion are common. The activity of axial disease does not parallel gut involvement.
Peripheral arthritis is seen in nearly 20% of patients. Peripheral arthritis manifests as an inflammatory, nonerosive, asymmetric oligoarthritis or monarthritis affecting large joints (knees, ankles, elbows), especially of the lower extremities. It is usually chronic but may be migratory and resolve in weeks or months. Enthesitis (i.e., heel pain) and “sausage digits” (toes or fingers) may occur. The activity of peripheral arthritis parallels gut inflammation. Peripheral arthropathy more frequently occurs in those with extraintestinal manifestations (e.g., erythema nodosum, uveitis).

Uncommon Findings: Clubbing, erosive arthritis, pericarditis, amyloidosis, thrombophlebitis, and pyoderma gangrenosum are rarely seen.

Diagnostic Tests: Abnormalities may include increased ESR or CRP, thrombocytosis, and hypochromic anemia. Synovial fluid WBC counts ranges from 2,000 to 50,000 cells/mm3.

Imaging: Axial disease is radiographically indistinguishable from AS. Periostitis and radiographic enthesitis may be present.

Keys to Diagnosis: The presence of spondylitis or a seronegative oligoarthritis along with GI symptom evidence of inflammatory bowel disease may suggest this diagnosis.

Differential Diagnosis: Articular disease may be confused with seronegative RA, other spondyloarthropathies, or Behçet’s syndrome. Arthritis and GI manifestations may be seen in the vasculitides, Whipple’s disease, celiac sprue, intestinal-bypass syndrome, scleroderma, amyloidosis, Henoch-Schönlein purpura, FMF, postdysenteric reactive arthritis, and lymphoma and in those with GI toxicity related to antirheumatic therapies.

Therapy: Control of colitis may improve the peripheral arthritis but not axial disease. Treatment options are similar to those used in AS. NSAIDs tend to be helpful. Rarely will NSAIDs exacerbate the enteritis. Corticosteroids are not advised in spondylitis but may be useful in low doses for peripheral arthritis or when injected intraarticularly for uncontrolled mono- or oligoarthritis. Sulfasalazine, MTX, and azathioprine should be reserved for those with uncontrolled peripheral arthritis, with or without active colitis. TNF inhibitors may be indicated with refractory axial disease.

Surgery: Joint surgery is seldom indicated. Bowel surgery may be indicated but not for arthritis alone.

BIBLIOGRAPHY

Holden W, Orchard T, Wordsworth P. Enteropathic arthritis. Rheum Dis Clin North Am 2003;29:513–530.PMID:12951865