Coeliac disease, also spelled celiac disease, and called celiac sprue, is an autoimmune disorder of the small intestine that occurs in genetically predisposed people of all ages from middle infancy onward. Symptoms include pain and discomfort in the digestive tract, chronic constipation and diarrhoea, failure to thrive (in children), anaemia and fatigue, but these may be absent, and symptoms in other organ systems have been described. Vitamin deficiencies are often noted in people with coeliac disease owing to the reduced ability of the small intestine to properly absorb nutrients from food.
IgA deficiency is present in 2.3% of people with coeliac disease, and in turn this condition features a tenfold increased risk of coeliac disease. Other features of this condition are an increased risk of infections and autoimmune disease. Dermatitis herpetiformis, an itchy cutaneous condition, has been linked to a transglutaminase enzyme in the skin, features small-bowel changes identical to those in coeliac disease, and may respond to gluten withdrawal even if no gastrointestinal symptoms are present
Serological blood tests are the first-line investigation required to make a diagnosis of coeliac disease. Antiendomysial antibodies of the immunoglobulin A (IgA) type can detect coeliac disease with a sensitivity and specificity of 90% and 99%, respectively. Serology for anti-tTG antibodies was initially reported to have a higher sensitivity (99%) and specificity (>90%) for identifying coeliac disease. However, it is now thought to have similar characteristics to anti-endomysial antibody
It found the rate increased from 5.2 per 100,000 in 1990 to 19.1 per 100,000 in 2011. This is a diagnostic phenomenon, not an incidence phenomenon Previous studies have suggested around 1% of the population would test positive for the condition - but the data from this study suggests only 0.25% are diagnosed. Coeliac UK say this means many are unaware they have the condition.