Eosinophilic Colitis

Eosinophilic colitis (EoC) is a rare disease in which a type of white blood cell called an eosinophil builds up in elevated numbers in the large intestine. This causes inflammation and injury to surrounding tissue.

When seen in infancy, EoC is often a benign, food-triggered condition that can resolve once the offending food is eliminated and outgrown. In adolescents and adults, however, EoC is typically chronic and recurring.

What Causes EoC?

The cause of EoC is unknown for many patients, but allergic factors may play a role. EoC can also occur alongside other eosinophilic gastrointestinal diseases (EGIDs) or conditions such as parasitic infections, inflammatory bowel disease, autoimmune disorders, or drug reactions. Cow’s milk protein and, in some cases, soy (even through breastfeeding or formula) often exacerbate symptoms in infants.

Who is Affected?

Eosinophilic colitis may affect both adults and children, and may affect both males and females. It often presents before 6 months of age, and the condition is often outgrown by early childhood, usually within the first decade of life.

People with a personal or family history of allergic disorders such as eczema, hay fever, asthma, or food allergies, or those with other eosinophil-associated diseases, may be at higher risk of developing eosinophilic colitis.

What Are the Symptoms of EoC?

Symptoms can vary by age and disease severity.

In infants, EoC often presents with:

Sudden onset of bloody diarrhea
Possible anemia (from blood loss)
Difficulty feeding or gaining weight
Occasional vomiting or signs of discomfort
Some infants appear otherwise healthy despite symptoms

In older children and adults, common symptoms include:

Diarrhea (bloody or non-bloody)
Abdominal pain or cramping
Fatigue
Nausea or vomiting
Weight loss or poor growth
Malnutrition

Significant blood loss at any age can cause anemia.

How Is EoC Diagnosed?

Eosinophilic colitis is diagnosed by a lower endoscopy (colonoscopy). During this procedure, a gastroenterologist passes a thin, flexible tube through the anus, rectum, and colon to look for visual signs of inflammation, erosions, or ulcers, and to collect tissue samples (biopsies).

A pathologist examines the biopsies under a microscope to count the number of eosinophils visible. The colon typically has low numbers of eosinophils present, and there are no consensus guidelines to suggest a threshold for what is considered elevated.

Therefore, diagnosis is based on clinical symptoms, visual evidence in the endoscopy, the pathology report, and how well the patient responds to therapy. High eosinophil levels can also occur in other conditions such as parasitic infections, inflammatory bowel disease, or autoimmune disease, so these causes must be ruled out before confirming EoC.

How Is EoC Treated?

There are no standardized, consensus guidelines for treating EoC, but the goal is to reduce eosinophil levels and inflammation to relieve symptoms and prevent tissue damage. Treatment goals include reducing the number of eosinophils, and the associated symptoms, inflammation, and damage. Two main therapies are used to manage EoC:

Dietary Therapy: Food allergies have been identified as having a possible role in EGIDs. While allergy testing is not always effective in identifying specific food triggers for EGIDs, your doctor may suggest it to help guide an elimination diet. Elimination diets (eliminating specific foods or food groups) and/or specialized amino-acid based formulas (elemental diets) may be recommended to help reduce eosinophils and improve symptoms. For some patients with EoC, especially infants, removing milk (sometimes along with soy) can improve symptoms.
Medications: Steroids such as prednisone (a systemic medication) or budesonide (a topically active medication) may be prescribed. Anti-inflammatory medications or immunomodulatory medications may also be prescribed.

To monitor response, periodic colonoscopies with biopsies may be recommended.

What Is the Prognosis for EoC?

The EoC that develops in infancy carries a good prognosis. It tends to spontaneously resolve, often within days. Dietary management has also shown to put EoC in remission, especially in the infant population.

For young adults and adults with EoC, prognosis depends on the response to treatment. EoC is chronic with periods of activity and periods of apparent remission. More aggressive medical management is often necessary, and may include antihistamines, glucocorticoids, and leukotriene receptors antagonists.

EoC can have a significant impact on quality of life. Complications can include severe malnutrition or dehydration.

Resources

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