OVERVIEW
Enteropathic arthritis (enteropathic arthritis) is a type of arthritis associated with inflammatory bowel disease and is a separate type in the classification of seronegative spondyloarthropathies. Arthropathic lesions can be associated with a variety of gastrointestinal disorders, such as inflammatory bowel disease arthritis, reactive arthritis after intestinal infections, Whipple’s disease, and small bowel bypass arthritis. However, enteropathic arthritis refers specifically only to arthropathy associated with ulcerative colitis and Crohn’s disease. Ulcerative colitis and Crohn’s disease are inflammatory bowel diseases with different characteristics, but both involve the intestinal mucosa and submucosa to cause chronic inflammation, and both arthritis manifestations are similar, so the combined arthritis of the two diseases can be considered a disease.
Etiology
The etiology of this disease is still unclear, there can be a variety of theories.
1. Genetic factors
Studies have found that ulcerative colitis, Crohn’s disease and ankylosing spondylitis all have genetic factors involved, and all three diseases are related to HLA-B12 to some extent.
2. Immune factors
There are the following findings in the immune basis of this disease: (1) there are non-specific anti-colonic antibodies in serum; (2) lymphocytes can damage colonic epithelial cells in tissue culture; (3) it is often accompanied by immune disorders, such as ocular uveitis and scleritis, erythema nodosum, autoimmune hemolytic anemia and so on.
3. Neurological factors
It is believed that cortical activity disorders can lead to autonomic dysfunction, causing intestinal hypermotility, intestinal vascular smooth muscle spasm, tissue ischemia, increased capillary permeability, resulting in the formation of intestinal mucosal inflammation, erosion and ulceration.
Symptoms
1. Intestinal manifestations
Most patients have abdominal pain, diarrhea, bloody stools or constipation, and the diagnosis of ulcerative colitis or Crohn’s disease is confirmed by colonoscopy and pathological tissue examination.
2. Spinal lesions
10% to 20% of patients with inflammatory bowel disease have spinal arthropathy, which may be symptomatic or asymptomatic. Spinal arthropathy may occur before or after inflammatory bowel disease, and some studies show that intestinal symptoms account for about 70% of the first symptoms, a small portion of the patients start their disease with low back pain or arthritis of the lower limbs of the knees and ankles, and about 10% of the patients have the onset of intestinal and arthropathy at the same time.
3. Other lesions
Pestle finger, uveitis, and skin lesions can be seen. These lesions are more common in patients with Crohn’s disease, and the cause is unknown. Skin lesions include erythema nodosum, erythema multiforme, and, rarely, pyoderma gangrenosum.
Tests
1. Laboratory tests
Erythrocyte sedimentation rate is elevated, RF and ANA are generally negative, and platelets are elevated.
2. Imaging
The X-ray or CT presentation of the spine and sacroiliac joints is similar to that of spondyloarthritis, but appears to be milder in patients with enteropathic arthritis. In sacroiliac arthritis, most patients with enteropathic arthritis present with unilateral lesions. A few patients may present with spinal vertebral bridges, widening of the pubic symphysis, narrowing of the hip joint space, and bone erosion.
3. Enteroscopy
In ulcerative colitis, colon examination reveals diffuse congestion, edema and erosion of the intestinal canal at the lesion site, small shallow ulcers with pus, or thickening of the intestinal canal, stenosis, and pseudo-polyps. Barium enema can be seen mucosal folds coarse and disorganized or fine granular changes, multiple shallow niche shadows or small filling defects, shortening of the intestinal tube, the disappearance of the colonic pouch can be tubular. Crohn’s disease has a wide range of lesions, the clinical manifestations can be similar to ulcerative colitis, but often no bloody stools, abdominal pain, mucus stools are common, and intestinal obstruction can also occur. The lesions are segmental with normal mucosa between the lesions.
Diagnosis
1. Clinical manifestations of enteropathy such as diarrhea, abdominal pain or intestinal obstruction.
2. ulcerative or granulomatous lesions of the intestinal tract confirmed by fiberoptic colonoscopy or surgery and diagnosed as ulcerative colitis or Crohn’s disease by gastroenterology specialists.
3. All are associated with arthritis or low back pain and may have imaging evidence of sacroiliac joint involvement.
Treatment
1. Immunosuppressant
Currently in clinical practice, sulfasalazine is often used as the first choice of drug, mainly because of the good efficacy of this drug on the intestinal lesion itself, in addition to methotrexate, leflunomide, azathioprine and other drugs are also widely used.
2. Biological agents
Studies have shown that infliximab has significant efficacy in 60% of Crohn’s disease, while etanercept is not as effective. Meanwhile, biological agents seem to be ineffective in ulcerative colitis.
3. Non-steroidal anti-inflammatory drugs (NSAIDs)
Although widely used and well tolerated, these drugs should be used with caution as there is evidence that they increase intestinal permeability, which may exacerbate intestinal inflammation.
4. Glucocorticoids
Glucocorticoid therapy may be added as appropriate in some patients.