Celiac Disease
Celiac disease (nontropical sprue, gluten enteropathy, celiac sprue) is a hereditary intolerance to gluten, a protein found in wheats, barley, and oats, which causes characteristic changes in the lining of the small intestine, resulting in malabsorption.
Celiac disease affects as many as 1 of 300 people in Italy and southwestern Ireland, yet it is extremely rare in Africa, Japan, and China. There is a genetic component; about 10% of people with celiac disease have a close relative with the disease. In this disease, gluten, a protein found in wheat and, to a lesser extent, barley, rye, and oats, is believed to stimulate the production of certain antibodies. These antibodies damage the inner lining of the small intestine, resulting in flattening of the villi. The resulting smooth surface leads to malabsorption of nutrients. However, the small intestine's normal brushlike surface and function are restored when the person stops eating foods containing gluten.
Symptoms
Some people develop symptoms as children, others not until adulthood. The severity of symptoms depends on how much of the small intestine is affected.
Adults with the more classic or typical form of the disease experience diarrhea, malnutrition, and weight loss. However, some people have no digestive symptoms at all. About 10% of people with celiac disease develop a painful, itchy skin rash with small blisters--a disease called dermatitis herpetiformis (see Section 18, Chapter 209).
In children, symptoms do not appear until foods containing gluten are introduced. Some children experience only mild upset stomach, whereas others develop painful abdominal bloating and have light-colored, unusually foul-smelling, bulky stools (steatorrhea).
The nutritional deficiencies resulting from malabsorption in celiac disease can cause additional symptoms, which tend to be more prominent in children. Some children develop growth abnormalities, such as short stature. Anemia, causing fatigue and weakness, develops as a result of iron deficiency. Low protein levels in the blood can lead to fluid retention and tissue swelling (edema). Malabsorption of vitamin B12 can lead to nerve damage, causing a pins-and-needles sensation in the arms and legs. Poor calcium absorption results in abnormal bone growth, a higher risk of broken bones, and painful bones and joints. Lack of calcium can also cause tooth discoloration and greater susceptibility to painful tooth decay. Girls with celiac disease may not have menstrual periods because of a low production of hormones, such as estrogen.
Diagnosis
The diagnosis is suspected when a person has the above-mentioned symptoms. Measurement of the level of specific antibodies produced when a person with celiac disease consumes gluten is a new and helpful test. The diagnosis is confirmed by an initial microscopic examination of a biopsy specimen revealing flattened villi of the small intestine and by a subsequent improvement in the lining after the person stops eating foods containing gluten.
Treatment and Prognosis
People with celiac disease must exclude all gluten from their diet, since eating even small amounts may cause symptoms. The response to a gluten-free diet is usually rapid. Once gluten is avoided, the brushlike surface of the small intestine and its absorptive function return to normal. Gluten is so widely used in food products that people with celiac disease need detailed lists of foods to be avoided and expert advice from a dietitian. Gluten is found, for example, in commercial soups, sauces, ice cream, and hot dogs.
Some people continue to have symptoms even when gluten is avoided. In such cases, either the diagnosis is incorrect or the disease has progressed to a condition called refractory celiac disease. In refractory celiac disease, treatment with corticosteroids, such as prednisone, may help. In rare cases, if there is no response to either gluten withdrawal or drug treatment, intravenous feeding is needed. Sometimes children are seriously ill when first diagnosed and need a period of intravenous feeding before a gluten-free diet is begun.
Although most people do well if they avoid gluten, long-standing celiac disease can be fatal in a small percentage of people who develop intestinal lymphoma. Whether strictly adhering to a gluten-free diet decreases the risk of long-term complications such as intestinal cancers or lymphoma is not known.
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