Idiopathic Eosinophilic Infiltration Syndrome

　　The etiology of idiopathic gastrointestinal eosinophilic infiltration syndrome has not been clarified to date. Due to the widespread infiltration of a large number of eosinophils in the lesion tissue, the peripheral blood of most patients shows an increase in eosinophils, and about 50% of patients have a personal or family history of allergic reactions, so this disease may be a systemic or local allergic reaction to endogenous or exogenous allergens. Increased levels of immunoglobulin IgG and IgA in serum also indicate the involvement of immune reactions.

　　After certain special allergens come into contact with sensitive mucosal tissue in the gastrointestinal wall, antigen-antibody reactions occur within the gastrointestinal wall, releasing histamine-like vasoactive substances, causing congestion, edema, and infiltration of eosinophils in the gastrointestinal mucosa, as well as spasm of gastrointestinal smooth muscle and increased mucus secretion, thereby causing a series of gastrointestinal symptoms.

　　Idiopathic gastrointestinal eosinophilic infiltration syndrome is prone to complications such as upper gastrointestinal bleeding, diarrhea, pyloric obstruction, and intestinal obstruction, which seriously harm the health of patients and must be treated in a timely manner.

　　Idiopathic gastrointestinal eosinophilic infiltration syndrome often presents with abdominal pain, nausea, and vomiting, with symptoms varying due to the location of the lesion. It usually has a chronic course, often with periodic attacks and spontaneous remission.

　　1, Type I

　　Type I is a generalized eosinophilic cell infiltrative gastroenteritis (abbreviated as eosinophilic gastroenteritis), including polyintestinal, monointestinal, and localized types, which is more common in people aged 30 to 50, with 80% having gastrointestinal symptoms. Half of the patients may have other allergic diseases, such as allergic rhinitis, asthma, etc. This type mainly presents with spasm pain in the upper abdomen, accompanied by nausea, vomiting, diarrhea, and other symptoms, with irregular attacks and may be related to certain foods. Severe involvement of the mucosa can lead to upper gastrointestinal bleeding, diarrhea, malabsorption, intestinal protein loss, iron deficiency, weight loss, and other symptoms. Marked involvement of the muscular layer can cause pyloric or intestinal obstruction, with corresponding symptoms and signs, and may be misdiagnosed as Crohn's disease or tumor. Peritoneal involvement can lead to the occurrence of ascites or pleural effusion containing a large number of eosinophils. Ascites is generally exudative.

　　2, Type II

　　Type II is a localized eosinophilic granulomatosis (abbreviated as eosinophilic granuloma), including localized and pseudopolypoid types, which is more common in people aged 40 to 60. This type often has a long history of gastric disease, with an acute onset, and may be accompanied by spasm pain in the upper abdomen, nausea, and vomiting. It is common to have peptic ulcers, often large ulcers. In pseudopolypoid types, upper gastrointestinal bleeding can be the only symptom. Lesions near the pylorus can cause pyloric obstruction. When the lesion is in the intestines, intestinal intussusception or obstruction can occur due to the formation of tumors, thickening of the intestinal wall, and edema, leading to functional disorders. Lesions in the ileum can cause an acute onset, and may be misdiagnosed as acute appendicitis due to right lower quadrant pain, tenderness, rebound pain, or local muscle tension.

　　The prevention of idiopathic gastrointestinal eosinophilic infiltration syndrome lies in avoiding the intake of allergenic foods or drugs. The key to the disease is to remove allergens and suppress allergic reactions. Actively seek out and exclude allergenic foods, and immediately stop eating foods or drugs that cause gastrointestinal allergies. For those without a history of food and drug allergies, a sequential method can be used to individually exclude possible allergenic foods, such as milk, eggs, shrimp, meat, and sensitive drugs. For those with mainly mucosal lesions, symptoms of abdominal pain and diarrhea improve rapidly after excluding allergenic foods or drugs.

　　What tests should be done for idiopathic gastrointestinal eosinophilic infiltration syndrome? Briefly as follows:

　　First, laboratory tests

　　1. Blood examination: 80% of patients have an increase in peripheral blood eosinophils, with (1-2)×109/L in patients with mucosal and submucosal lesions and muscular layer lesions, and up to 8×109/L in patients with predominantly plasma cell lesions. There may also be iron deficiency anemia, decreased serum albumin, increased blood IgE, and rapid blood sedimentation.

　　2. Stool examination: The significance of stool examination in eosinophilic gastroenteritis is to exclude intestinal parasitic infection. Some cases may show Charcot-Leyden crystals, and the routine stool examination shows occult blood positivity. Some patients have mild to moderate steatorrhea. The Cr labeled albumin increases, the alpha-antitrypsin clearance rate increases, and the D-xylose absorption test is abnormal.

　　Second, other auxiliary examinations

　　1. X-ray examination: Eosinophilic gastroenteritis lacks specificity, and X-ray barium meal shows mucosal edema, widened folds, nodular filling defects, thickening of the gastrointestinal wall, stenosis, and obstruction.

　　2. CT examination: It can detect thickening of the gastrointestinal wall, enlargement of mesenteric lymph nodes, or ascites.

　　3. Endoscopy and biopsy: Endoscopy and biopsy are suitable for eosinophilic gastroenteritis with mucosal and submucosal lesions. Under the microscope, mucosal folds can be seen to be large, congested, edematous, ulcerated, or nodular. Biopsy can confirm a large number of eosinophilic infiltration pathologically, which is valuable for diagnosis. However, the biopsy tissue is not of much value for patients with lesions mainly affecting the muscular layer and serosa, and sometimes surgical pathological confirmation is needed.

　　4. Peritoneal puncture: Diagnostic peritoneal puncture must be performed in patients with ascites, as the ascites is exudative, containing a large number of eosinophils. It is necessary to perform a smear staining of ascites to distinguish eosinophils from neutrophils.

　　5. Laparoscopic examination: Under laparoscopy, there is a lack of specific manifestations, with mild cases showing peritoneal congestion; severe cases can be similar to peritoneal metastatic cancer. The significance of laparoscopic examination lies in the performance of biopsy of abdominal mucosal tissue to obtain a pathological diagnosis.

　　6. Surgical exploration: It is generally not recommended to perform exploratory laparotomy to confirm suspected eosinophilic gastroenteritis, but surgery is performed when there is intestinal obstruction, pyloric obstruction, or suspected tumor.

　　Patients with idiopathic gastrointestinal eosinophilic infiltration syndrome should avoid spicy foods, and it is best not to eat milk, fish, shrimp, and seafood products. Pay special attention to dietary hygiene, especially in summer, wash raw fruits and vegetables before eating, and do not eat deteriorated food. Because contaminated and deteriorated food contains a large number of bacteria and bacterial toxins, which have a direct destructive effect on the gastric mucosa. Foods stored in the refrigerator must be cooked thoroughly before eating, and if deterioration is found, it must be discarded resolutely and prohibited from being eaten. Eat less fatty, sweet, thick, greasy, spicy, and other foods, and drink less alcohol and strong tea.

　　What are the treatment methods for idiopathic gastrointestinal eosinophilic infiltration syndrome? The following is a brief description:

　　1. Actively seek and exclude allergens

　　It should be immediately stopped to eat foods or drugs that may cause gastrointestinal allergies, such as milk, eggs, shrimp, and allergic drugs, etc. After excluding the relevant sensitizing foods or drugs for those with mainly mucosal lesions, abdominal pain and diarrhea can be improved rapidly.

　　2. Corticosteroids

　　Corticosteroids have good therapeutic effects, can alleviate the condition, and most patients improve within 1-2 weeks after taking the medicine. It is suitable for patients with diffuse type, postoperative recurrence, and ascites as the main symptom. During the acute phase, prednisone can be given, and the dose can be gradually reduced to maintenance dose after the effect is seen. The duration of use of eosinophilic granuloma can be appropriately extended. If the effect of hormones is not significant, other immunosuppressants can be added, such as azathioprine, etc.

　　3. Disodium cromoglycate

　　Disodium cromoglycate is a mast cell membrane stabilizer. Clinically, for patients who are ineffective or have severe side effects from adrenocortical hormone treatment, this drug can be used as an alternative.

　　4. Surgical Treatment

　　Surgical treatment cannot remove the infiltrated areas, and mucosal edema makes it difficult to perform gastrointestinal anastomosis, and it is easy to recur after surgery. Therefore, since the use of corticosteroids, eosinophilic gastroenteritis does not require surgical treatment. Surgical treatment can be considered when there is gastrointestinal obstruction due to eosinophilic granuloma and内科 treatment is ineffective. Depending on the situation, low-dose prednisone can be taken orally after surgery to maintain it.