Could stomach pain and diarrhea be a gastrointestinal allergy?

Authors: Pan Siyuan, Li Qingshang, East China Hospital Affiliated to Fudan University.

Review: Ma Jianxia, Chief Physician at Huadong Hospital, Fudan University.

Case Story

Xiao Wang is a 30-year-old man who has become a frequent visitor to the emergency room over the past six months, experiencing recurrent abdominal pain and diarrhea, sometimes accompanied by nausea and vomiting. Each visit, he assumed he was suffering from acute gastroenteritis. Blood tests, however, only indicated an elevated percentage of eosinophils. After taking anti-diarrheal and gastrointestinal medications, he found only temporary relief, with his symptoms persisting. Doctors advised that he might need further examinations, including gastrointestinal endoscopy, to make a clear diagnosis. Determined to find a solution, Xiao Wang chose to be hospitalized. Following a series of tests, a large number of eosinophils were detected in the gastric antrum mucosa, leading to a diagnosis of "eosinophilic gastroenteritis." After treatment with steroids, Xiao Wang's gastrointestinal symptoms gradually improved, and eosinophil levels in his peripheral blood returned to normal.

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Disease Unveiled

Eosinophilic gastroenteritis is a disease of unknown origin. Our bodies contain white blood cells known as "eosinophils," which act as "little guardians" that help us respond to allergic reactions and fend off parasitic infections. However, when these cells proliferate uncontrollably and accumulate in large numbers within the gastrointestinal tract, they can trigger an inflammatory response. This inflammation can lead to a range of digestive symptoms including abdominal pain, diarrhea, and nausea. The disease can manifest at any age, but it is more prevalent in individuals aged 30 to 50, with a higher incidence in men compared to women.

Clinical manifestations

1. Signals from the gastrointestinal tract: discomfort occurs where there is "invasion."

(1) Damage to the "mucosal layer" affects digestion and absorption: This leads to recurrent abdominal pain, diarrhea, nausea, and vomiting, similar to symptoms of acute gastroenteritis. However, conventional anti-diarrheal medications and stomach treatments provide only temporary relief and are prone to recurrence. In severe cases, blood vessels in the mucosa and submucosa may rupture, resulting in mucus and blood in the stool, which can appear bright red, dark red, or tarry. If the affected area of the small intestinal mucosa is extensive, it can impair nutrient absorption, leading to malnutrition, weight loss, and anemia. In children, this may result in growth and developmental delays.

(2) Involvement of the "muscle layer" can lead to a "rigid" gastrointestinal tract: If the esophagus becomes blocked, there may be constant acid reflux and difficulty swallowing, as if food is stuck. If the "pylorus," the connection between the stomach and the small intestine, is obstructed, it can cause frequent nausea and vomiting, along with abdominal bloating, where vomit may contain food from the previous night and have a sour smell. If the small or large intestine is blocked, it can trigger abdominal pain, bloating, nausea, and vomiting, or even lead to a lack of gas or bowel movements, indicating intestinal obstruction.

(3) Involvement of the "serous layer" can result in "fluid accumulation" in the abdomen and chest: this is less common and primarily presents as pleural or abdominal effusion, which may occur alone or with symptoms of inflammation in the mucosal and muscular layers. A hospital visit for fluid extraction for examination can reveal a high presence of eosinophils, which is vital for diagnosing lesions in this layer.

2. Non-gastrointestinal symptoms: Often linked to allergies and can easily be overlooked.

The most common symptoms are allergy-related. In addition to gastrointestinal discomfort, approximately 50% of patients may also display symptoms related to allergies, leading to misdiagnoses due to oversight. Respiratory allergy symptoms may include asthma, allergic rhinitis, and other conditions. Skin allergy symptoms can range from eczema to urticaria and allergic dermatitis. Many individuals with these symptoms who display elevated eosinophils in their blood may mistakenly believe they are only dealing with allergies, unaware that eosinophilic gastroenteritis could be the underlying issue.

Systemic symptoms are another category, often resulting from nutrient malabsorption in the gastrointestinal tract, and can include weight loss, anemia, and fatigue.

Diagnosis Strategy

The diagnosis of eosinophilic gastrointestinal disease is based on the "Tally criteria." In simple terms, three conditions must be met.

1. Symptoms of gastrointestinal discomfort should appear.

These include abdominal pain, bloating, nausea and vomiting, diarrhea, and indigestion. In severe cases, symptoms may include the presence of mucus or blood in the stool and cessation of bowel movements or gas. Only with clear symptoms indicating "abdominal issues" will the disease be considered.

2. An elevated proportion of eosinophils is detected.

This is key to diagnosis, relying on two types of examinations to "collect evidence": first, "gastroscopy + biopsy," which involves taking tissue samples from areas such as the esophagus, stomach, and intestines. If eosinophils cluster under a microscope, this indicates characteristics of the disease. The second type involves "radiological examination + blood tests." If CT scans or barium meals reveal abnormalities in the colon, and blood tests show increased eosinophils, a diagnosis can be made.

3. Exclusion of other easily confused diseases.

Many other diseases can also cause gastrointestinal discomfort and elevated eosinophil levels, such as parasitic infections, Crohn’s disease, and ulcerative colitis. These can lead to multi-systemic diseases like connective tissue diseases, eosinophilia, and lymphoma. During diagnosis, doctors will consider these possibilities to avoid misdiagnosis.

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Treatment Plan.

1. Dietary Therapy: First, investigate issues related to "eating."

(1) Immediately discontinue any food or medications identified or suspected to be unsafe.

(2) Attempt to "eliminate 6 common allergens": milk, eggs, soy (e.g., tofu and soy milk), wheat (e.g., steamed buns and noodles), nuts (e.g., walnuts and peanuts), and seafood shellfish (e.g., shrimp, crab, and clams).

(3) Maintain a "Food Diary": Keep a small notebook to record daily food intake (e.g., if you had milk and bread for breakfast) and note any subsequent symptoms such as stomach pain or diarrhea. This practice can help identify "suspicious foods" to inform your doctor about potential allergens.

While dietary control may not cure this condition, it is a fundamental approach for all treatment strategies.

2. Medication Treatment: Tailored to the Situation

(1) Glucocorticoids: The primary medication for rapid symptom relief. A dosage of prednisone ranging from 0.5 to 1 mg/(kg·d) can lead to improvements in gastrointestinal symptoms for approximately 80% of patients within 1 to 2 weeks, alongside a gradual decrease in peripheral blood eosinophils. Subsequently, the glucocorticoid dosage should be gradually reduced to a maintenance level of 5 to 10 mg/d. Some patients may experience a relapse after discontinuing this medication.

(2) Immunotherapy: For patients who do not respond well to glucocorticoid treatment or who relapse during dosage reduction or experience recurrent flare-ups, additional immunomodulatory drugs may be introduced, such as azathioprine or interleukin-5 antagonists.

(3) Other antihistamines: Medications like ketotifen, sodium cromoglycate, montelukast, and anti-IgE humanized monoclonal antibodies (omalizumab) can also provide supportive care.

3. Surgical treatment: An "emergency measure" used only as a last resort.

In general, surgery is not necessary and is only considered under two specific circumstances: 1) obstruction that cannot be resolved through hormonal treatment; 2) the emergence of other surgical emergencies, such as perforation, ineffective treatment of bleeding, or necrosis.

Following surgery, if abdominal discomfort or a high eosinophil count persists, the doctor may suggest a low dose of hormones for a period to prevent relapse.

Precautions

Although eosinophilic gastroenteritis is generally a benign condition that may resolve spontaneously, attention must be paid to its tendency for "recurrence." Daily care and regular monitoring are crucial. Patients should adopt healthy lifestyle and dietary habits, avoid late nights and emotional fluctuations, and schedule regular medical follow-ups to monitor any changes in their condition.

In conclusion, while eosinophilic gastroenteritis is rare, it can significantly impact patients' quality of life. It is vital to seek prompt medical attention, undergo appropriate treatments, and make necessary lifestyle adjustments when dealing with such conditions. I hope every patient can recover their health under scientific guidance and return to a normal life soon. A healthy diet and positive mindset are goals that everyone should strive for.