Coeliac disease is caused by an immune reaction to gluten, a protein found in wheat, barley and rye. The reaction causes inflammation and damage to the lining of the small bowel, which impairs its ability to absorb nutrients.
Coeliac disease occurs in people with a genetic susceptibility and can develop at any stage of life. Typical symptoms include fatigue, bloating, cramps and diarrhoea, but some people have no symptoms at all, and in others the only clue may be anaemia (due to iron or folic acid deficiency) or an unusual itchy skin rash (dermatitis herpetiformis). Coeliac disease often runs in families and can be associated with diabetes and/or thyroid disease.
Screening blood tests (to detect antibodies to tissue transglutaminase and gliadin) are available; if they are positive, a small bowel biopsy should be performed to confirm the diagnosis. The blood tests can become negative after a few months of strict gluten avoidance, so if you think there’s a possibility you might have coeliac disease it’s best to have the blood tests before you go on a gluten-free diet. If you’re already avoiding gluten, four to six weeks of regular gluten ingestion is required before having blood taken for screening.
Genetic testing. If you or another family member has coeliac disease, a genetic test (HLA DQ2/DQ8 typing) can be done to determine who else in the family is at risk.
Currently, a life-long gluten-free diet is the only known treatment. Untreated coeliac disease carries a long-term risk of nutritional deficiencies, osteoporosis and/or bowel malignancy.