Gluten allergy is called Coeliac disease as well. It affects the small intestine.
Gluten refers to a substance that is found in wheat, barley and rye. This is a cause of damage on the lining of bowels. It brings negative effect because the lining damaged is used to absorb the nutrients and vitamins needed by the body.
The allergy can be detected at any age. However, for children it can easily be diagnosed immediately after they are being introduced to their diets. This is not a typical allergy because if left uncured, it can result to anaemia and other cancerous diseases.