Coeliac Disease: Diagnosis and Care in Luxembourg

Confusing coeliac disease with the gluten-free trend is one of the most common mistakes about it. It is, in fact, a genuine autoimmune condition, in which eating gluten triggers an immune reaction that damages the lining of the small intestine. It has nothing to do with a dietary choice or a passing sensitivity: left undiagnosed and untreated, it can lead to lasting nutritional deficiencies. In Luxembourg, the gastroenterologist establishes the diagnosis, usually after a referral from the GP based on suggestive symptoms.

An autoimmune disease, not a diet

In someone with coeliac disease, gluten — a protein found in wheat, barley and rye — triggers an attack by the immune system against the lining of the small intestine. This attack damages the intestinal villi, the tiny structures that absorb nutrients, which is why the disease can cause deficiencies even in people who eat enough. This autoimmune mechanism sets it clearly apart from so-called "non-coeliac" gluten sensitivity, which can cause similar symptoms but without this measurable intestinal damage, and from the gluten-free trend chosen for comfort or belief without a medical diagnosis.

Symptoms that are not always digestive

The classic picture combines abdominal pain, bloating, diarrhoea or abnormal stools, and weight loss. But coeliac disease very often shows up differently: unexplained chronic tiredness, iron-deficiency anaemia resistant to usual treatment, joint pain, recurring mouth ulcers, fertility problems, or a characteristic skin rash called dermatitis herpetiformis. In children, it can show up as delayed growth or delayed puberty. This wide range of presentations is why the diagnosis is sometimes made late, after years of symptoms being attributed to other causes.

The trap to avoid before any diagnosis

This is the single most important point to remember: gluten should never be stopped before the diagnostic tests have been done. The screening blood tests (looking for specific antibodies) and the intestinal biopsy that confirms the diagnosis are only reliable if the person keeps eating gluten normally at the time of testing. Stopping gluten as a precaution, thinking it is the safe thing to do, can normalise the results and make the diagnosis impossible to confirm afterwards — sometimes requiring gluten to be reintroduced for several weeks to redo the tests, an uncomfortable period that could have been avoided.

The diagnostic pathway and care

Faced with suggestive symptoms, the GP orders an initial blood test, then refers to a gastroenterologist if the result is positive. The specialist performs an upper digestive endoscopy with biopsies to confirm the intestinal damage. Once diagnosed, no medication replaces strict, lifelong avoidance of gluten: it is the only treatment, but it is effective, with gradual healing of the intestine over several months. Regular follow-up with the gastroenterologist and sometimes a dietitian checks recovery and helps adjust the diet. Consultations and tests are covered by the Caisse nationale de santé under the usual rules, detailed on cns.lu.

Living gluten-free day to day

Avoiding gluten requires care with labelling — it hides in many processed products — but it does not mean a restrictive or joyless diet: more and more products and restaurants now offer reliable alternatives, and the choice in Luxembourg has grown noticeably in recent years. The key is consistency, including for small amounts that seem harmless, since even minimal exposure keeps the intestinal inflammation going in someone with coeliac disease.

A condition that can run in families

Coeliac disease has a strong genetic component: having a parent or a sibling with the condition raises the risk, which is why first-degree relatives are sometimes screened even without obvious symptoms. It is also associated with other autoimmune conditions — type 1 diabetes, thyroiditis — which is why the gastroenterologist stays alert to these particular backgrounds during follow-up. This family dimension, sometimes silent, is one more reason not to dismiss mild symptoms in a relative of someone already diagnosed.

Special attention in children

In children, coeliac disease can go unnoticed for a long time behind simple growth delay, tiredness at school, or recurring stomach aches put down to school stress. Paediatricians stay alert to these subtle signs, particularly during routine growth check-ups, since an early diagnosis avoids lasting effects on development. Once diagnosed, children often adapt to the gluten-free diet more easily than adults, especially when the whole family gets involved in adjusting eating habits at home.

Nutritional follow-up beyond the diagnosis

Because the intestinal damage affects nutrient absorption, some people are found to have iron, folate, vitamin B12 or vitamin D deficiencies at the time of diagnosis, sometimes requiring temporary supplementation alongside the gluten-free diet. A dietitian can help make sure the new diet stays balanced, since some ready-made gluten-free products are more processed and less nutrient-dense than their standard equivalents. This nutritional check-up is usually repeated a few months after diagnosis to confirm that the gut has properly healed and that absorption has returned to normal.