Crohn's disease arthritis

　　The etiology of Crohn's disease arthritis is still unclear. There are theories of infection with bacteria, viruses, fungi, protozoa, etc.; theories of lymphatic obstruction and lymphocyte aggregation; and theories of inflammatory circulation disorders, etc., which are all difficult to determine. It has been confirmed that most patients with HLA-1327 are positive, indicating that genetic predisposition is a pathogenic factor for the disease. In recent years, considering the diversity of pathological morphology, the chronic inflammatory characteristics of the disease, the presence of granulomas, multi-systemic damage such as arthritis, skin damage, and the effectiveness of immunosuppressive treatment, immunoregulatory mechanism disorders are also an important cause of pathogenesis.

　　The local complications of Crohn's disease arthritis include fistulas or fistulas, perirectal infections, intestinal obstruction, intestinal perforation, and peritoneal abscesses; systemic complications include arthritis, nodular erythema, and vasculitis, etc.

　　Crohn's disease arthritis mainly occurs in young and middle-aged adults, with 15-35 years old being more common. Elderly patients are mainly affected by the colon, with ileocecal lesions accounting for more than 50%, lesions limited to the colon accounting for 10%, and both the colon and small intestine being affected accounting for more than 30%. The onset is usually gradual. The specific symptoms are as follows:

　　I. Digestive system

　　Abdominal pain is the most common symptom, with pain usually located around the umbilicus and the lower right abdomen. It is a mild colic or discomfort before defecation, which can be relieved after defecation. Diarrhea usually occurs 3 to 6 times a day. Due to malabsorption of bile acids, water, and fats, the stool is semi-liquid. When the lesion involves the colon, fecal incontinence may occur, with the feeling of urgent need to defecate. In the later stage of the disease, a mass can be palpated.

　　II. Skin

　　Erythema nodosum is a common skin lesion in this disease, usually parallel to the activity of the disease, mainly distributed on the extensor side of the lower limb, and some may form ulcers.

　　Necrotizing fasciitis is a deep, necrotic ulcerative skin injury, with marked pain, most often located in the anterior compartment of the tibia in the lower limb, often accompanied by systemic symptoms. The lesion is usually solitary, but can also be multiple or extensive. If not treated, the lesion can progress to the deep tissue and cause osteomyelitis. Other skin lesions include eczema, maculopapular rash, erythema, urticaria, and polymorphic erythema, etc.

　　III. Arthritis

　　1. Peripheral arthritis:10% to 20% of Crohn's disease patients may develop peripheral arthritis, which is the most common extraintestinal manifestation of Crohn's disease, mainly seen in patients with colonic involvement. The involved joints are similar to those in ulcerative colitis, and it is a subacute asymmetric oligoarthritis, most commonly affecting the knee joints, followed by ankle joints, then shoulder, wrist, elbow, metacarpophalangeal joints, and large joints are more susceptible than small joints. Lower limb joints are more susceptible than upper limb joints. Arthritis usually does not leave deformities, but can cause joint pain, tenderness, and sometimes joint effusion. Joint symptoms generally last for several weeks or even more than a month.

　　2. Spondylitis:1% to 25% of patients may develop ankylosing spondylitis, with about 5% determined by strict criteria. Most patients have no obvious sacroiliac joint symptoms, and the number of sacroiliitis detected by radiological examination is three times higher than that of symptomatic sacroiliitis. Spondylitis can occur before, after, or simultaneously with intestinal lesions, and is not parallel to the activity of intestinal lesions. Controlling intestinal symptoms will not alleviate spondylitis. Some patients may develop clubbing, particularly in those with involvement of the upper segment of the small intestine. Patients with clubbing have a higher incidence of internal fistulas and malabsorption.

　　IV. Urogenital system

　　Urolithiasis is a common complication of Crohn's disease, more common in patients who have undergone colectomy and ileostomy. This may be due to severe diarrhea or ileostomy causing the loss of a large amount of secretions, urine concentration, leading to a decrease in urine pH and the formation of uric acid stones. Impaired absorption of bile salts also leads to excessive absorption of oxalates in the small intestine, which is another cause of urinary tract stones. In addition, obstructive pyelonephritis, perinephric abscess, renal amyloidosis, and the formation of intestinal fistulas can also lead to urinary tract lesions and cause urolithiasis.

　　V. Other

　　Patients may have varying degrees of fever, and some patients may experience blepharitis, conjunctivitis, keratitis, corneal ulceration, and episcleritis, etc. Ocular manifestations generally occur during the acute exacerbation phase of intestinal lesions, disappear when the condition improves, but may recur.

　　Prevention methods for Crohn's disease arthritis:

　　One, Eliminate and reduce or avoid the factors leading to the disease, improve the living environment and space, develop good living habits, prevent infection, pay attention to dietary hygiene, and make reasonable dietary arrangements.

　　Two, Pay attention to physical exercise, increase the body's ability to resist diseases, do not overwork, over-consume, quit smoking and drinking.

　　Three, Early detection, early diagnosis, early treatment, establish confidence in overcoming the disease, and persist in treatment.

　　The clinical examination of Crohn's disease arthritis is as follows:

　　One, Blood routine and erythrocyte sedimentation rate:Anemia can be caused by hemorrhage or bone marrow suppression, as well as malabsorption of folic acid or vitamin B12. Different degrees of leukocytosis and increased erythrocyte sedimentation rate can reflect the activity and inflammation of the lesion.

　　Two, Biochemical examination:Elevated serum α2-globulin, and in patients with marked diarrhea, common symptoms of hypokalemia, hypomagnesemia, and hypocalcemia are due to widespread intestinal mucosal involvement and malabsorption of vitamin D. Hypoproteinemia is caused by protein leakage. The glycine and bile acid content ratio in duodenal fluid is increased, indicating widespread terminal ileal lesions. Serum lysozyme can reflect the degree of inflammation of active granulomas, with a normal value of 5mg/L, and in this disease, it is above 10mg/L, which can be used to judge the activity of the disease stage and observe the therapeutic effect. In extensive small bowel resection, there is an abnormal iodine-polyvinylpyrrolidone test (I-PVP) (normal fecal excretion rate)
　　Three, Immunological examination:Rheumatoid factor and lupus cells are all negative. Individuals with positive HLA-B27 are prone to peripheral arthritis or ankylosing spondylitis, and serum IgA indicates a good prognosis.

　　Four, X-ray examination:The site of onset is most commonly the terminal ileum. In the early stage, due to submucosal inflammation and edema, X-ray examination shows thickening, flattening, and disappearance of intestinal mucosal folds. The morphology of the involved intestinal tract is relatively fixed, but there is generally no obvious narrowing. Other intestines may show segmentation, dilation, and other functional changes. Due to increased secretion, barium often disperses in patchy form. With the progression of the disease, there may be a large amount of granulation tissue proliferation in the submucosa, and mucosal folds may appear as pebble-like or polypoid filling defects. After ulcer formation, when the intestinal lumen is filled with barium, the outline is often serrated or pointed, which is the location of the pit shadow. The外形 of the intestinal tract is often fixed, local peristalsis disappears, and the intestinal spaces may widen due to thickened intestinal walls. In the late stage, large amounts of fibrosis may occur in the intestinal segments, and when the intestinal lumen is significantly narrowed, X-ray shows the intestinal lumen as a linear irregular narrowing, mucosal folds disappear, and the length of the narrowed segment varies from 1-2 cm to a longer range, and can be discontinuous and multiple. Sometimes, X-ray manifestations of mechanical intestinal obstruction are seen, but it is mostly incomplete intestinal obstruction.

　　Limiting colitis is less common when it only invades the colon, mostly occurring in the right colon, especially in the cecum, and often accompanied by terminal ileal lesions. When the colon is involved, it can occur in multiple segments and affect the left colon as well. In the early stage, it is characterized by an increased colonic motility and obvious stimulatory signs, with barium not easily filling, and in the chronic phase, the intestinal lumen narrows, the colonic pouches become shallow or disappear, mostly unilaterally, but sometimes symmetrically. The edges of the intestinal tract may have papillary protrusions or longitudinal small ulcers.

　　In addition to changes in the small and large intestines, multiple peripheral arthritis can also occur, but joint erosion changes may not appear on X-rays. The X-ray changes of sacroiliitis are similar to those of ankylosing spondylitis. Acheson (1960) found that in 742 cases of limited ileitis, 2-3% had ankylosing spondylitis.

　　5. Endoscopic examination:Fiber colonoscopy can detect small and early lesions, and a definitive diagnosis can be obtained through biopsy. Endoscopic findings include: 1. Ulcers; 2. Mucosa呈铺路石形; 3. Congestion, edema; 4. Bag-shaped changes, stricture, and formation of pseudopolyps. There are two types of intestinal wall ulcers: one is a small ulcer, which is more common in the early stage; the other is a larger, round, elliptical, or linear ulcer, and typical granulomas and nonspecific inflammation can be found through biopsy at the lesion site. Sigmoidoscopy is only valuable for rectal and sigmoid colon lesions, and in some patients, granulomas can be seen. For patients with esophageal, gastric, duodenal, and jejunal lesions, fiberoptic endoscopy can be performed.

　　Patients with Crohn's disease arthritis should avoid seafood, and it is also not recommended to drink milk or dairy products during the active phase of the disease. It is advisable to avoid coarse fiber foods and rough processed foods. Try to limit dietary fiber, such as chives, celery, sweet potatoes, radishes, coarse grains, and dried beans. During the active phase of the disease, raw vegetables and fruits should be avoided, and they can be consumed in the form of vegetable broth, mashed vegetables, fruit juice, and pureed fruit. Large pieces of meat should not be cooked, and it is recommended to use minced meat, diced meat, shredded meat, minced meat, steamed egg custard, and boiled eggs. It is not advisable to eat greasy foods, spicy foods, and avoid chili, mustard, alcohol, and other spicy刺激性 foods. Eat less garlic, ginger, and scallions. Also, avoid eating overly cold or hot foods. It is not advisable to consume alcohol, tea, coffee, cold foods, and condiments.

　　There are three main treatment methods for Crohn's disease arthritis:

　　1. General treatment:This includes sulfasalazine (sulfasalazine), glucocorticoids, azathioprine, and others. Intestinal tuberculosis should be ruled out before use. For those who have difficulty in diagnosis, anti-tuberculosis treatment can be initiated for 2-3 months.

　　SSZ is the first-line medication, starting with 2-3g per day, taken orally in four divided doses. During the active phase, 4-6g per day is recommended, with a maintenance dose of 2-3g per day. If the medication is ineffective after 2 weeks, prednisone can be used at a dose of 30-40mg per day, taken orally in 3-4 divided doses. In severe cases, ACTH 20-40U can be administered intramuscularly or intravenously. Patients with descending colon lesions can also receive hydrocortisone enema. SSZ is effective for early cases, and the dose should be reduced as soon as possible after improvement. It is contraindicated in patients with intra-abdominal infection and sepsis, and should be used with caution in patients with fistula formation. Long-term use can cause dysbacteriosis, increasing the number of surgical cases and significantly raising the mortality rate.

　　Azathioprine or mercaptopurine (6-mercaptopurine) combined with corticosteroids can reduce the dosage of the latter, but it is not better than SSZ and corticosteroids when used alone. Metronidazole (Flagyl) 0.4-0.6g per day, taken orally in 2-3 divided doses, is effective for less refractory cases.

　　2. Surgical treatment:More than 70% of patients require surgery, and acute cases are often misdiagnosed as acute appendicitis and operated on. Once it is found to be the disease, appendectomy cannot be performed, otherwise an intestinal fistula may form. Indications for surgery include irreversible intestinal stricture or obstruction, refractory intestinal fistula, intra-abdominal abscess, perforation, massive hemorrhage, malignancy, and failure of medical treatment. The efficacy of surgery is not as good as that of ulcerative colitis, and the recurrence rate is as high as 50% or more. After surgery, due to changes in bile acid metabolism and changes in the intestinal flora, it can cause disturbances in organic acid metabolism, cholelithiasis, urinary tract stones, or articular disorders. Sometimes surgery can become a direct or indirect cause of death, so it should be handled with caution, and the extent of resection should not exceed 3.0 cm.

　　3. Symptomatic treatment:During the acute and active stages, it is advisable to rest in bed quietly, avoid fatigue and mental stimulation, and provide high-calorie, low-fat, low-fiber, and easily digestible food. Iron supplements, various vitamins and electrolytes (sodium, potassium, chlorine, calcium, magnesium), blood transfusions, plasma, human serum albumin, and various amino acid preparations should be administered. Parenteral hyperalimentation is beneficial to improve intestinal function and enhance the physical condition of the patient. It ensures that young people's development is not affected. Diarrhea caused by extensive ileal lesions or after resection can be treated with colestyramine (cholestyramine), and those with poor fat absorption can use medium-chain triglycerides. Infection should be treated with antibiotics, but attention should be paid to the possibility of causing ulcerative colitis-like enteritis with lincomycin and clindamycin (chloro-lincomycin). The above treatments can produce明显 effects in early patients.