Eosinophilic Gastrointestinal Disease - Classification, Pathophysiology, Diagnosis, and Treatment

What Is Eosinophilic Gastrointestinal Disease?

Eosinophilic gastrointestinal diseases are rare conditions that affect the gastrointestinal tract. A triad of eosinophilic infiltration characterizes this disease condition in the different gastrointestinal tract segments. Eosinophils are white blood cells that are raised due to allergic reactions. It is a part of the immune system. When the eosinophil count increases, it will lead to redness and swelling. It affects both children and adults.

Organs affected by the disease are the esophagus, stomach, small intestine, and colon. The common symptoms include nausea, vomiting, malnutrition, and abdominal pain. The severity of the disease condition usually occurs based on the location, extent, and depth of bowel wall involvement. Gastrointestinal problems are the complications of the disease. Life-threatening conditions are rare with this type of disease. The other names of this disease are eosinophilic gastritis, eosinophilic gastro enteropathy, and eosinophilic gastrointestinal disease.

What Are the Causes of Eosinophilic Gastrointestinal Disease?

The exact causative agent which causes eosinophilic gastrointestinal disease is unknown. In some conditions, it is thought to be hypersensitivity to certain foods and unknown allergens.

What Type of Population Is Affected?

It affects both men and women. Men have slightly more chances of getting the disease, as per studies. The age group of 20 to 50 years is affected. Eosinophilic gastroenteritis is seen more in people with a history of allergy, eczema, and asthma.

What Is the Classification of Eosinophilic Gastrointestinal Disease?

1) Based on the Depth of Involvement:

• Mucosal.

• Muscular.

• Serosal.

2) Based on the Occurrence in the Area of the Gastrointestinal Tract:

• Eosinophilic esophagitis.

• Eosinophilic gastritis.

• Eosinophilic gastroenteritis.

• Eosinophilic colitis.

What Is the Pathophysiology of Eosinophilic Gastrointestinal Disease?

This condition involves any part of the gastrointestinal tract from the esophagus to the colon. Eosinophils are present in the mucosal layer as a defense mechanism. When these eosinophils invade the deeper layer, it becomes a disease condition. In disease conditions, eosinophilic infiltration and degranulation occur in the gastrointestinal walls. In this condition, factors cytokine interleukin-3 and cytokine interleukin -5, and granulocyte-macrophage cause migration and activation of eosinophils. In patients with allergies, the allergens will cross the intestinal mucosa, triggering an inflammatory response leading to the migration of eosinophils. In this condition, eosinophils in blood and serum immunoglobulin E are elevated.

When the eosinophils attack the mucosal layer, it leads to protein-losing enteropathy and malabsorption. When eosinophils invade the muscular layer, it will cause abdominal pain, vomiting, and bowel obstruction. When eosinophils go deeper and invade the serosal layer, it will lead to ascites (fluid collects in the space within the abdomen) with marked eosinophilia.

What Is Eosinophilic Esophagitis?

This type of eosinophilic gastrointestinal disease occurs in the esophagus. The eosinophils accumulate in the esophagus, causing redness, swelling, and damage in that area. The symptoms are:

• Difficulty in swallowing.

• Food sticks to the esophagus.

• Nausea (urge to vomit).

• Vomiting.

• Poor growth.

• Malnutrition (lack of proper nutrients required).

• A burning feeling in the esophagus.

• Abdominal pain (pain is usually dull or sharp and occurs in the chest, stomach, or intestine).

• Lack of appetite (the patient refuses to take food).

What Are Eosinophilic Gastritis and Eosinophilic Gastroenteritis?

Eosinophilic gastritis occurs within the stomach. Eosinophilic gastroenteritis affects both the stomach and small intestine. The white blood cell eosinophils accumulate in the stomach and intestine, leading to redness, swelling, and destruction. It affects any age group of people. It is usually diagnosed in 30 to 50-year age group patients. The symptoms are:

• Difficulty in eating.

• Weight loss.

• Nausea.

• Vomiting.

• Poor growth.

• Abdominal pain (it may be dull or sharp shooting pain).

• Anemia (blood count is reduced).

• Fatigue (overtired and feeling of low energy).

What Is Eosinophilic Colitis?

This type of eosinophilic gastrointestinal disease occurs in the large intestine. The eosinophils invade the large intestine causing redness, swelling, and inflammation in that area. Eosinophilic colitis is common in infants below six months of age. The symptoms are:

• Anemia (low blood count).

• Nausea.

• Vomiting.

• Malnutrition.

• Poor growth.

• Weight loss.

• Weight gain difficulty.

• Bloody diarrhea (loss of stools containing blood. The blood's color appears bright red or black).

How Is Eosinophilic Gastrointestinal Disease Diagnosed?

If any of the above-mentioned symptoms are present, it is always good to take medical advice from the healthcare provider. The doctor will ask for the symptoms, onset duration, and medical history. The doctor performs a physical examination. The diagnosis is made based on the four criteria:

• Presence of gastrointestinal symptoms.

• Eosinophilic infiltration of the gastrointestinal tract.

• Exclusion of parasitic disease.

• Absence of systemic involvement.

The doctor will ask for laboratory tests to rule out the conditions. Laboratory tests are:

• Blood Count: It plays an important role in diagnosis. Complete blood count or eosinophil count is checked. The normal eosinophil count is 500 eosinophils (eos)/L. During eosinophilic gastrointestinal disease, the count ranges from 1000 eos/L to 8000 eos/L. The eosinophil count in patients with mucosal involvement is 2000 eos/L; in muscular involvement, it is 1000 eos/L, and in serosal involvement, it is 8000 eos/L. The value of mean corpuscular volume indicates iron deficiency anemia. Low serum albumin levels indicate eosinophilic gastrointestinal disease with mucosal involvement.

• Stool Test: It is done to identify any bacterial or parasitic infections. In stool, steatorrhea (excretion of fat in feces) is found in mild to moderate levels.

• Skin Prick Test: To identify the allergens.

• Alpha-1 Antitrypsin Levels: Fecal protein loss is measured by this method. It helps to identify the inability to digest and absorb the protein's gastrointestinal tract. The normal range of the value is zero to 54 mg/dl. The rise in the value of alpha-1 antitrypsin is a good marker for diagnosis.

• Computed Tomography Scan (CT scan): Nodular and irregular thickening of the distal stomach and proximal small bowel folds is seen. These types of changes are also noticed in Crohn's disease. So, it must not be the only test to evaluate the disease condition.

• Ultrasonography: Ascitic fluid, which is present in the serosal layer, is identified through this method.

• Endoscopy: It helps to view the upper gastrointestinal tract. During this procedure, the doctor passes a flexible tube with a camera at the tip known as an endoscope. The tube passes through the esophagus, stomach, and intestine. A doctor can view if any changes are present based on the history given by the patient. If any inflammatory changes are found, small scrapping of the tissue is done. The scrapped tissue is sent for biopsy.

• Colonoscopy: It helps to examine the lower portion of the gastrointestinal tract. The test is similar to that of endoscopy. A flexible tube passes through the anus, rectum, and colon.

How to Treat Eosinophilic Gastrointestinal Disease?

The treatment aims to reduce the redness, swelling, and damage caused by eosinophilic gastrointestinal disease.

1. Diet: The food that causes allergy is found out and eliminated because the food taken will cause more inflammation. Dietary changes help to reduce the symptoms of the disease condition. A dietician or a nutritionist helps to provide a good diet chart.

2. Corticosteroids: It is the most effective group of drugs. The action of corticosteroids is by limiting the action of the immune system and reducing the inflammation of the digestive tract. Studies have shown that it is effective in 90 % of people. The drugs prescribed usually are Prednisolone, Fluticasone inhaled, and Budesonide oral viscous suspension.

3. Antihistamines: These drugs act by blocking the inflammatory effect of histamine.

4. Mast Cell Stabilizers: These drugs limit the effect on certain immune system cells.

5. Proton Pump Inhibitors: It helps to get relief from reflux symptoms. These drugs affect the glands in the stomach and reduce the acid produced.

6. Nonsteroidal Anti-inflammatory Drugs (NSAID): Drugs like Ibuprofen help to reduce pain and swelling.

7. Surgery: Rarest treatment modality. Recurrence is possible even after surgery.

Conclusion:

Eosinophilic gastrointestinal disease is a rare disease of the digestive tract. The main cause of the allergy is food allergens. In order to avoid allergens, a trial elimination diet can be considered. In the trial elimination diet, most allergy-causing substances such as milk, egg, wheat, soya, and beef are avoided. By avoiding the food allergens, the symptoms will subside. This disease does not pose any life-threatening condition and becomes fatal. Eosinophilic gastrointestinal disease is a treatable type of disease.