Celiac Disease

Celiac disease is a digestive disease that damages the small intestine and interferes with absorption of nutrients from food. People who have celiac disease cannot tolerate a protein called gluten, found in wheat, rye, and barley. Gluten is found mainly in foods but may also be found in products we use every day, such as stamp and envelope adhesive, medicines, and vitamins.

The prevalence of celiac disease is about 1 in 250 people in Italy, and 1 in 300 people in Ireland. Recent findings estimate about 2 million people in the United States have celiac disease, or about 1 in 133 people.

Symptoms and Complications

Celiac disease affects people differently. Symptoms may occur in the digestive system, or in other parts of the body. For example, one person might have diarrhea and abdominal pain, while another person may be irritable or depressed. In fact, irritability is one of the most common symptoms in children.

Symptoms of celiac disease may include one or more of the following:

• gas
• recurring abdominal bloating and pain
• chronic diarrhea
• constipation
• pale, foul-smelling, or fatty stool
• weight loss/weight gain
• irritability
• fatigue
• unexplained anemia (a low count of red blood cells causing fatigue)
• bone or joint pain
• tingling numbness in the legs (from nerve damage)
• muscle cramps
• seizures
• missed menstrual periods (often because of excessive weight loss)
• delayed growth
• failure to thrive in infants
• pale sores inside the mouth, called aphthous ulcers
• tooth discoloration or loss of enamel
• itchy skin rash called dermatitis herpetiformis

A person with celiac disease may have no symptoms. People without symptoms are still at risk for the complications of celiac disease, including malnutrition. The longer a person goes undiagnosed and untreated, the greater the chance of developing malnutrition and other complications. Anemia, delayed growth, and weight loss are signs of malnutrition: The body is just not getting enough nutrients. Malnutrition is a serious problem for children because they need adequate nutrition to develop properly.

Complications

Damage to the small intestine and the resulting nutrient absorption problems put a person with celiac disease at risk for malnutrition, anemia, and several other diseases and health problems.

• Lymphoma and adenocarcinoma are cancers that can develop in the intestine.

• Osteoporosis is a condition in which the bones become weak, brittle, and prone to breaking. Poor calcium absorption contributes to osteoporosis.

• Miscarriage and congenital malformation of the baby, such as neural tube defects, are risks for pregnant women with untreated celiac disease because of nutrient absorption problems.

• Short stature refers to being significantly under the average height. Short stature results when childhood celiac disease prevents nutrient absorption during the years when nutrition is critical to a child’s normal growth and development. Children who are diagnosed and treated before their growth stops may have a catch-up period.

Dermatitis Herpetiformis

Dermatitis herpetiformis (DH) is a severe, itchy, blistering skin manifestation of celiac disease. Not all people with celiac disease develop dermatitis herpetiformis. The rash usually occurs on the elbows, knees, and buttocks. Unlike other forms of celiac disease, the range of intestinal abnormalities in DH is highly variable, from minimal to severe. Only about 20 percent of people with DH have intestinal symptoms of celiac disease.

To diagnose DH, the doctor will test the person’s blood for autoantibodies related to celiac disease and will biopsy the person’s skin. If the antibody tests are positive and the skin biopsy has the typical findings of DH, patients do not need to have an intestinal biopsy. Both the skin disease and the intestinal disease respond to a gluten-free diet and recur if gluten is added back into diet. In addition, the rash symptoms can be controlled with medications such as dapsone (4',4'diamino-diphenylsuphone). However, dapsone does not treat the intestinal condition and people with DH should also maintain a gluten-free diet. 

Causes

When people with celiac disease eat foods or use products containing gluten, their immune system responds by damaging the small intestine. The tiny, fingerlike protrusions lining the small intestine are damaged or destroyed. Called villi, they normally allow nutrients from food to be absorbed into the bloodstream. Without healthy villi, a person becomes malnourished, regardless of the quantity of food eaten.

Villi on the lining of the small intestine help absorb nutrients.

Because the body’s own immune system causes the damage, celiac disease is considered an autoimmune disorder. However, it is also classified as a disease of malabsorption because nutrients are not absorbed. Celiac disease is also known as celiac sprue, nontropical sprue, and gluten-sensitive enteropathy.

Celiac disease is a genetic disease, meaning it runs in families. Sometimes the disease is triggered—or becomes active for the first time—after surgery, pregnancy, childbirth, viral infection, or severe emotional stress.

Diseases Linked to Celiac Disease

People with celiac disease tend to have other autoimmune diseases. The connection between celiac disease and these diseases may be genetic. These diseases include

• thyroid disease
• systemic lupus erythematosus
• type 1 diabetes
• liver disease
• collagen vascular disease
• rheumatoid arthritis
• Sjögren’s syndrome

Diagnosis

Recognizing celiac disease can be difficult because some of its symptoms are similar to those of other diseases. In fact, sometimes celiac disease is confused with irritable bowel syndrome, iron-deficiency anemia caused by menstrual blood loss, Crohn’s disease, diverticulitis, intestinal infections, and chronic fatigue syndrome. As a result, celiac disease is commonly underdiagnosed or misdiagnosed.

Recently, researchers discovered that people with celiac disease have higher than normal levels of certain autoantibodies in their blood. Antibodies are protective proteins produced by the immune system in response to substances that the body perceives to be threatening. Autoantibodies are proteins that react against the body’s own molecules or tissues. To diagnose celiac disease, physicians will usually test blood to measure levels of

• Immunoglobulin A (IgA)
• anti-tissue transglutaminase (tTGA)
• IgA anti-endomysium antibodies (AEA)

Before being tested, one should continue to eat a regular diet that includes foods with gluten, such as breads and pastas. If a person stops eating foods with gluten before being tested, the results may be negative for celiac disease even if celiac disease is actually present.

If the tests and symptoms suggest celiac disease, the doctor will perform a small bowel biopsy. During the biopsy, the doctor removes a tiny piece of tissue from the small intestine to check for damage to the villi. To obtain the tissue sample, the doctor eases a long, thin tube called an endoscope through the mouth and stomach into the small intestine. Using instruments passed through the endoscope, the doctor then takes the sample.

Screening

Screening for celiac disease involves testing for the presence of antibodies in the blood in people without symptoms. Americans are not routinely screened for celiac disease. Testing for celiac-related antibodies in children less than 5 years old may not be reliable. However, since celiac disease is hereditary, family members, particularly first-degree relatives—meaning parents, siblings, or children of people who have been diagnosed—may wish to be tested for the disease. About 5 to 15 percent of an affected person’s first-degree relatives will also have the disease. About 3 to 8 percent of people with type 1 diabetes will have biopsy-confirmed celiac disease, and 5 to 10 percent of people with Down syndrome will be diagnosed with celiac disease.

Reference:

National Digestive Diseases Information Clearinghouse, USA.