Celiac disease: pathophysiology, diagnosis, and management

Celiac disease is considered to be one of the most common inflammatory diseases of the bowel. It is caused by a dietary source and occurs in those individuals who are genetically predisposed to be intolerant to gluten. In Celiac disease, the patient is intolerant to a protein that in called gluten, and is commonly found in wheat, barley and oat products. If a patient with celiac disease ingests a gluten containing substance, then he or she immediately has an immune system response that damages the first layer of the small intestine and causes interference with the absorption of nutrients from other foods. To be more specific, there inflammatory response causes damage to the tiny, fingerlike protrusions within the small bowel called villi. The villi function to absorb foods into the bloodstream and when damaged can cause problems for the patient.

The actual prevalence of celiac disease has been shown to be far more frequent than what was previously believed. It is the most common genetic disease in Europe although it is rarely diagnosed in African, Chinese and Japanese people. It has been noted that with the discovery of serological testing for population, the prevalence may be even higher in these populations than what was previously supposed. The diagnosis of celiac disease is a difficult one, in part because of the wide rage of clinical symptoms, either related to or unrelated to the digestive systems.

Celiac disease tends to effect different people in different ways. There is a bimodal presentation with the diagnosis in childhood and in the 4th and 5th decade of life. There appears to be some association with whether or not a patient was breastfed, as breastfeeding tends to stave of the symptoms of the disease as well as preventing some of the more atypical disease symptom logy. Celiac disease has also been associated with early intake of foods that contain gluten, and how rich the diet is in foods that contain gluten. The symptoms may be digestive or occur outside of the digestive systems. Presentation may be very variable. Symptoms may include (but are not confined to) recurring abdominal bloating and pain, chronic diarrhea, weight loss, pale, foul smelling stools, unexplained anemia, abdominal distention and gas, bone pain, behavior changes (especially common when the condition is diagnosed in children), muscle cramps, fatigue, delayed growth or failure to thrive, pain in joint, seizures, tingling and numbness in the legs, sores in the mouth (canker sores or aphthous ulcers), painful skin rash called dermatitis herpetiformis, tooth discoloration, abnormal periods and other dyspeptic symptoms. The anemia, growth delay and weight loss can all be attributed to the malnutrition, which occurs with celiac disease. There are also patients in whom the disease is completely asymptomatic. In these patients, there are some, undamaged portions of the bowel which are still able to absorb the nutrients, therefore allowing enough to be taken in to prevent the symptoms occurring.

The diagnosis of celiac disease can be a problem, since the symptoms are so diffuse and also mimic some other diseases like Crohn's disease, ulcerative colitis, chronic fatigue, depression, infection, fibromyalgia, etc. Clinicians must be aware of the subtleties of the disease and inspect the patient for things like emaciation, pallor, low blood pressure, peripheral edema, easy bruising, abdominal distention, decrease in deep tendon reflexes or muscle spasms, all which may be due to vitamin deficiencies. A skin condition that is called dermatitis herpetiformis is often seen with celiac disease, and would tip the clinician off to the presence of the disease, especially in light of the other nebulous symptoms. It presents as an intensely itchy skin eruption with small papules or vesicles. The symptoms of intense burning, stinging and itching cannot be overemphasized. The lesions are usually symmetrically distributed on the extensor surfaces of the body: over the elbows, knees, buttocks, scalp, posterior, neck, sacral (lower end of the spinal column) and shoulder areas. The face and facial hairline are occasionally affected. Very rarely the lesions occur within the mouth. Varying in its severity, the condition usually persists indefinitely and is a lifelong condition. There are only a few patients in whom the disease remits for long periods of time.

The lesions may first appear as discolorations and next consist of small bumps called papules and small blisters called vesicles. These lesions tend to occur in groups much like the lesions of Herpes, hence the term herpetiformis, meaning "like Herpes." Because of the intense itching, the lesions are often scratched; these scratched areas will then develop crusts and often then heal with changes in color, either those of hypopigmentation or hyperpigmentation. Most DH patients can usually predict the location of a new lesion as much as 8 to 12 hours before the actual onset because of the symptoms of localized burning and itching. Though the blisters tend to come out in crops, all stages can be seen at any one time. The blisters may take from 7 to 10 days to lose their itching and burning sensations and then begin to crust. They are rarely inflamed and don't contain pus. Although there are recorded cases of the lesions occurring on the lips and within the mouth, it is extremely unusual for lesions to occur on mucous membranes (soft tissues at body openings) in other areas of the body.

Patients who have celiac disease develop elevated levels of certain antibodies in the blood. It is known that the body produces antibodies in response to something which is physically threatening. There are antibody tests, which can be measured in the blood, which are specific for celiac disease and include AEA (Immunoglobulin A anti-endomysium antibodies), AGA (IgA anti-gliadin antibodies), AGG (IgG anti-gliadin antibodies) and tTGA (IgA Anti-tissue transglutaminase).