Celiac disease

Celiac disease can affect different organs and different parts of the body. But some people have celiac disease without any noticeable symptoms. The most common symptoms are:

• Tiredness and mood changes such as irritability, feeling down, or even depression
• Digestive problems such as abdominal pain, persistent diarrhea or constipation, a bloated belly
• Loss of appetite, weight loss (in adults) or lack of weight gain, delayed growth or development (in children and teenagers)

Younger children with celiac disease may have other symptoms such as vomiting or problems with tooth enamel.

A very rare form called Duhring’s disease (or dermatitis herpetiformis) affects the skin, leading to symptoms such as redness, burning and itching, clusters of blisters, a rash and bumps.

Celiac disease can develop in people who have certain genes (HLA gene types DQ2 or DQ8). Just over 30 out of 100 people in Germany have these genes. But only about 2 to 3 out of 100 people with these genes develop celiac disease. It is still not clear why they have an autoimmune reaction to gluten and others don’t.

The risk of celiac disease is also higher in people who already have another autoimmune disease such as type 1 diabetes, Hashimoto’s disease or rheumatoid arthritis. For example, up to 10 out of 100 people with type 1 diabetes have celiac disease.

Celiac disease runs in families, too. About 10 to 15 out of 100 first-degree relatives of people with celiac disease also have it. Because of this, it is recommended that the children and parents of people who are diagnosed with celiac disease are tested for it, too. It can also be a good idea to be tested if your siblings or grandparents have celiac disease.

Some experts believe that gastrointestinal infections (tummy bugs) during childhood can increase the risk of celiac disease, but it's not yet clear whether that's the case.

About 1 to 2% of people in Europe have been diagnosed with celiac disease.

If left untreated, celiac disease leads to permanent inflammation in the small intestine. The tissue changes: The finger-like protrusions (villi) in the mucous membrane become flatter and can no longer absorb as many nutrients. The grooves (crypts) between the villi in the small intestine get deeper, too.

Over time, that often leads to nutrient deficiencies that can cause anemia and constant fatigue. Even though the inflammation first occurs in the small intestine, it can spread to other areas of the body and cause a variety of symptoms – like a skin rash or movement and walking problems (e.g. trembling and balance problems).

In the vast majority of people who follow a strict gluten-free diet, the intestine recovers and the symptoms go away. If the symptoms don't go away after changing your diet, it is called “refractory celiac disease.” Fewer than 1% of people with celiac disease currently have this form. Refractory celiac disease is practically unheard of in children.

Chronic inflammation in the intestine isn't the only effect of untreated celiac disease. If you don't change your diet, it can cause bone problems and osteoporosis in the long term. Untreated celiac disease can already cause growth problems and damage bones in children and teenagers. That can also happen in children and teenagers who don't have many typical celiac disease symptoms, or don't have any symptoms at all.

If celiac disease is not discovered or treated, it can damage the liver and cause problems with nerves (neuropathies). It can also make it harder to have children and lead to complications during pregnancy.

Continuing to eat gluten over many years can increase your risk of cancer – for example, in your digestive tract, head, neck, and chest area. The risk of tumors in the lymphatic system (T-cell lymphoma) is especially high.

All of these effects and risks can be avoided or reduced by sticking to a strictly gluten-free diet.

Celiac disease often goes unnoticed for a long time. Because of this, it's important to tell your doctor about all of the symptoms you have, even those that are not typical of celiac disease.

If you're more likely to develop celiac disease – for example, because close relatives have it or because you have another autoimmune disease such as type 1 diabetes – it can be a good idea to see a doctor and be tested for it even if you don’t have any symptoms.

The diagnosis involves taking a sample of blood and testing it in a laboratory

• to look for immunoglobulin A (IgA) antibodies against an enzyme called tissue transglutaminase (tTG or TG2), and
• to measure the concentration of IgA, which is important for interpreting the above reading.

Increased levels of tTG-IgA antibodies are a sign of celiac disease. The results come back after about one week.

The test is only reliable if you eat enough gluten beforehand. Because of this, it's important not to avoid gluten if you think you might have celiac disease. People who have already reduced the gluten in their diet have to increase it again for about three months before they are tested for celiac disease.

As well as the blood test, the diagnosis usually involves taking tissue samples from the upper part of your small intestine during a gastroscopy (where a thin tube with a tiny camera is inserted through your mouth and stomach). If the tissue is found to be damaged in the typical way, that confirms that you have celiac disease. Children with very high tTG antibody levels may not need to have tissue samples taken.

If the tissue samples and blood test don't lead to clear results, identifying what type of HLA gene you have can help to rule out celiac disease. This is also done by taking a sample of blood and testing it in a laboratory, where they look for specific gene sections that are always present in those who have the disease.

In Germany, people who are diagnosed with celiac disease are given a “celiac disease passport” (Zöliakie-Pass) that contains all of the diagnostic test results. This document confirms that you have an official diagnosis, which can be important if you change doctors. Later test results can also be noted down there.

If you are diagnosed with celiac disease, following a strict gluten-free diet is usually enough for the lining of the intestine to heal and the symptoms to get better. You have to stick to the diet permanently because eating gluten will always lead to inflammation in the lining of the intestine. It is important to avoid even the smallest amounts of gluten because they also cause problems.

Digestive problems normally go away if you stick to a strict gluten-free diet. But that can take a number of weeks, or often even several months. Other symptoms such as exhaustion and tiredness often get better if you avoid gluten.

Permanently changing your diet means having to change some lifestyle habits, too. Practical tips and tricks can help here, as well as talking to others affected by the disease.

When people are ill or need medical advice, they usually go to see their family doctor or pediatrician first. People who think they may have celiac disease can also make an appointment to see a gastroenterologist.

In our topic "Health care in Germany" you can read about how to find the right doctor – and our list of questions can help you to prepare for your appointment.

The website of the German society for celiac disease (Deutsche Zöliakie Gesellschaft) offers a lot of practical information about living with celiac disease, including where to find support groups in Germany.