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Celiac Disease

Written by Ada’s Medical Knowledge Team

Updated on

What is celiac disease?

Celiac disease is a serious, lifelong condition caused by the immune system reacting to gluten, a protein found in wheat, rye, barley and several other grains. It causes inflammation and damage in the small intestine and can result in a wide range of symptoms throughout the body. 1 2

Symptoms of celiac disease in adults and children may include: 1 3 4

However, many people have no symptoms or only mild symptoms, which can make a timely diagnosis challenging. Celiac disease often goes unrecognized; only a small fraction of people with the condition are diagnosed. 5 4 2

Celiac disease can affect anyone, of any age, though it tends to be more common among women than men. It occurs in approximately one out of every 100 people. There seem to be two peak periods in the appearance of symptoms – one in the first year of life, between eight and 12 months of age, and the second between approximately 20-40 years of age. Celiac disease is linked to certain genes and is often found to run in families. 1 3 6

In people with celiac disease, eating food that contains gluten causes a severe response from the immune system; it mistakenly damages the lining of the small intestine, leading to difficulty absorbing nutrients and a number of potential complications. 1 4 2

There is currently no cure or way to prevent celiac disease. The only treatment for celiac disease is a lifelong gluten-free diet. Following a strict gluten-free diet allows the lining of the small intestine to heal, clearing up symptoms and reducing the likelihood of developing complications. Any ingestion of gluten will result in damage to the intestine and a relapse of symptoms. 1 3 4 2

Celiac disease symptoms

The symptoms of celiac disease can vary widely and range from mild to severe. If present, they are typically persistent.

Gastrointestinal (digestive tract) symptoms in adults may include: 5 1 3 4 7

  • Transient abdominal (belly) pain
  • Bloating
  • Flatulence or excess wind
  • Fatty, pale, smelly stools that float in the toilet
  • Diarrhea or, rarely, constipation
  • Poor appetite
  • Nausea and vomiting

Other signs and symptoms of celiac disease in adults may include: 5 1 4 8 7

  • Fatigue and lethargy
  • Anemia
  • Severe or persistent mouth ulcers, or canker sores
  • Dermatitis herpetiformis, a type of rash
  • Unintentional weight loss
  • Lack of menstruation
  • Infertility
  • Repeated miscarriage
  • Osteoporosis
  • Unexplained bone or joint pain
  • Dental enamel problems
  • Ataxia, loss of coordination
  • Peripheral neuropathy; tingling, numbness or pain in the hands and feet
  • Headaches
  • Irritability
  • Depression or anxiety
  • Dementia, in older people

Many adults with celiac disease do not have any symptoms, or only have mild symptoms. 4 People experiencing symptoms that they suspect may be linked to celiac disease can carry out an assessment using the free Ada app.

Causes of celiac disease

Celiac disease is caused by a severe response to gluten, a type of protein found in wheat, barley, rye and several other grains. In some people who carry genes called HLA-DQ2 and HLA-DQ8, eating foods containing gluten can trigger the body’s immune system to mistakenly damage the lining of the gut. 1 It is not understood exactly why this happens. 9

Reacting to gluten, the immune system causes inflammation and irritation in the lining of the small intestine. The villi, which are tiny, tube-like projections in the lining and play a key role in the absorption of digested food, become flattened. This is called villous atrophy and can lead to malabsorption, with serious nutritional deficiencies and health complications as a result. 5 1 3 4 2

Risk factors for celiac disease

Celiac disease can affect anyone, of any age and racial background. However, certain factors may make a person more likely to develop celiac disease. These include: 1 4 8

  • Having a close relative, e.g. a parent or sibling, with celiac disease; this significantly increases one’s risk
  • Having another autoimmune condition, e.g. Hashimoto’s thyroiditis, type 1 diabetes or rheumatoid arthritis
  • Turner syndrome, a disorder in which a female only has one out of two X chromosomes
  • Down syndrome, also known as trisomy 21

Celiac disease and “leaky gut”

The terms “leaky gut” and “leaky gut syndrome” are often encountered by people looking for information on celiac disease and/or gluten sensitivity. Leaky gut and leaky gut syndrome are not recognized medical terms. They refer to something known as intestinal permeability, which means the ease with which substances are able to move through the mucosal barrier, or wall, of the small intestine. 10 11 12 13

In a healthy intestine, the gaps between cells in the mucosal barrier are usually very small, only allowing appropriately digested nutrients and other substances through to the bloodstream. However, certain substances and conditions can cause the gaps to widen or the intestinal barrier to become “loose” or “leaky”. Celiac disease is one such condition. It is thought that gluten may cause increased intestinal permeability in a number of people without celiac disease, too. 10 11 12 13

There is a theory that increased intestinal permeability might allow potentially harmful substances, e.g. undigested proteins, bacteria and toxins, to pass from the gut into the bloodstream and cause widespread inflammation in the body, with a range of resulting health problems. 10 11 12 13

There is not enough evidence to confirm many of the ideas about leaky gut and the possible effects it may have in the body. Doctors generally recommend eating a balanced, healthy diet for optimal digestive and overall health. 10 11 12

If you have any questions about your digestive health, it is recommended that you consult a medical doctor.

Diagnosis of celiac disease

After taking the person’s medical history and performing a physical examination, a doctor will typically order blood tests if celiac disease is suspected. If the results suggest that celiac disease is present, a biopsy will then be recommended to confirm the diagnosis. 1 4

Good to know: If you think that you might have celiac disease, it is very important that you do not go gluten-free until you have spoken to a doctor and been tested, if necessary. Adopting a gluten-free diet can interfere with the blood test and biopsy results and may cause a false negative. 1 9

Celiac disease blood test

A blood test is used to check for the antibodies, proteins that typically fight infection and which are typical of celiac disease. These include IgA tissue transglutaminase (IgA tTG), endomysial IgA and IgG deamidated gliadin peptide. The levels of these antibodies are usually only high in people with celiac disease. 9 A doctor may also recommend blood tests to check for nutritional deficiencies, e.g. iron deficiency. 1

Celiac disease biopsy

If the blood test shows high levels of the antibodies found in celiac disease, a diagnosis will typically need to be confirmed with a biopsy of the duodenum, the first part of the small intestine. This involves a doctor taking a small sample of tissue, typically using an endoscope – a thin tube that is passed down the throat into the stomach and intestine. The sample is examined for signs of the characteristic damage caused by celiac disease. 1 9

Genetic test for celiac disease

In some cases, it may be possible to have a test to check for the presence of the genes that are associated with celiac disease. Not having HLA-DQ2 or HLA-DQ8 genes means that developing celiac disease is highly unlikely. However, having the genes does not mean that a person will develop celiac disease; the majority of people with a genetic predisposition to celiac disease never develop the condition. 14 15

Celiac disease treatment

There is currently no cure for celiac disease – treatment requires adopting a completely gluten-free diet. In addition, certain supplements and vaccinations may be recommended to help prevent complications from celiac disease. 5 1 4

Gluten-free diet

The only effective treatment for celiac disease is a diet that is 100 percent free of gluten. Following a strict gluten-free diet typically results in a rapid improvement in symptoms; a person will usually start to feel better within a couple of weeks, and the lining of the small intestine will start to heal. 5 1 3 4 2

A strict gluten-free diet must be followed for life; the consumption of even a very small amount of gluten can cause damage to the small intestine and trigger a relapse of symptoms. 1

Gluten is found in the following grains: 5 1 3 4

  • Wheat
  • Rye
  • Barley
  • Spelt
  • Einkorn
  • Kamut
  • Triticale

Any foods that contain the above, e.g. breads, pastries and many cereals, will therefore also contain gluten, and must be avoided. Sauces, snack foods, ready-made meals, beers and even medicines are among the many products that often contain gluten; labels should always be checked carefully.

Gluten is not found in the following unprocessed starches:

  • Rice
  • Potatoes
  • Corn

Oats and celiac disease

There are differing opinions on whether oats are suitable for people with celiac disease. Oats contain a protein called avenin, which is similar to gluten. For some people with celiac disease, this does not seem to be a problem. However, others find that it causes a relapse of symptoms and/or damage to the small intestine. Furthermore, some brands of oats may be contaminated with gluten from the factories they are processed in. Some celiac disease authorities advise that oats be included in a person’s diet, while others recommend avoiding all oats and oat products. A doctor may be able to advise on what is most appropriate for a particular person’s dietary needs. 16 8 17 18

Good to know: It is possible to enjoy a balanced, healthy diet that does not contain any gluten. Fruit, vegetables, dairy, soya, eggs, fish and meat are all gluten-free, and gluten-free breads, snacks and other products are increasingly available. A doctor will be able to offer advice and/or refer a person to a dietician, support groups and information resources.

Other measures

A doctor may recommend the following measures to help prevent nutritional deficiencies and other complications from celiac disease: 1 19

  • Taking a vitamin, calcium or iron supplement, for at least six months after diagnosis
  • Having the seasonal “flu jab”, the yearly influenza vaccination
  • Having other vaccinations, e.g. the Hib vaccine to prevent blood poisoning and pneumonia, and the pneumococcal vaccine 20

Complications of celiac disease

Maintaining a strictly gluten-free diet is essential to prevent symptoms and lower the likelihood of complications from celiac disease. Eating even a tiny amount of gluten can cause symptoms and increase the risk of developing complications. 1

Complications associated with poorly managed celiac disease include: 5 1 9

  • Vitamin D deficiency, iron deficiency and other nutrient deficiencies
  • Osteoporosis
  • Skin problems, e.g. dermatitis herpetiformis
  • Ulcers in the intestine, known as ulcerative jejunitis
  • Weakened functioning of the spleen and possibly the immune system as a result 20
  • Other autoimmune conditions, e.g. type 1 diabetes and Hashimoto’s thyroiditis
  • Anxiety and depression
  • Rarely, lymphoma, a cancer of the intestinal lymph system, and other cancers of the gastrointestinal tract 21
  • Infertility
  • In undiagnosed women having a child, low birth weight, premature birth or miscarriage
  • In children, stunted growth, delayed puberty and dental problems

Non-responsive celiac disease

About one in 10 people with celiac disease will continue to experience symptoms after they have switched to a strict gluten-free diet. This is often caused by hidden sources of gluten in the diet, but may also be the result of: 5 9

  • Food intolerances, e.g. lactose, a sugar found in cow’s milk
  • Food allergies
  • Bacterial overgrowth in the small intestine
  • Irritable bowel syndrome
  • Microscopic colitis
  • A deficiency of pancreatic enzymes
  • Refractory celiac disease

Refractory celiac disease

A small number of people with celiac disease may continue to experience gastrointestinal symptoms even on a confirmed gluten-free diet, or experience short-term relief when going gluten-free and then a recurrence of symptoms. This is called refractory celiac disease. The cause is unknown, and the condition requires treatment with immunosuppressive medication, e.g. steroids. 9

Prevention of celiac disease

Previously, it was thought, by not introducing gluten into a baby’s diet until they were 4-6 months old, it might be possible to prevent or slow the development of celiac disease. However, recent research shows that the period at which gluten is first introduced does not affect the development of the condition. It is not yet possible to prevent celiac disease in children or adults. 22 23

Nonetheless, early diagnosis and treatment can help to prevent further development of, and complications from, celiac disease. It is recommended that anyone who experiences symptoms, or could be considered to be at risk for the condition, ask a doctor about screening. For people who are diagnosed with celiac disease, following a strict gluten-free diet can help to prevent further damage to the digestive tract and other complications. 23

Celiac disease in children

Celiac disease can affect people of any age, including infants and children. If present, symptoms of celiac disease in children are typically persistent.

Gastrointestinal (digestive tract) symptoms in children may include: 24 25

  • Diarrhea or constipation
  • Fatty, pale and smelly 1 stools that float in the toilet
  • Bloating or abdominal (belly) pain
  • Flatulence, commonly known as gas
  • Weak appetite
  • Nausea and vomiting 1 4

Other signs and symptoms in children may include: 24 25

  • Fatigue
  • Anemia
  • Unexplained weight loss or difficulty gaining weight
  • Delayed growth and/or puberty
  • Severe or persistent mouth ulcers, or canker sores
  • Dermatitis herpetiformis, a type of rash
  • Dental problems, e.g. discolored teeth or grooves in the teeth
  • Thinning of the bones
  • Anxiety and/or irritability 26
  • Sleep disturbances

Many children with celiac disease do not have any symptoms, or only have mild symptoms. 4

If a child is suspected of having celiac disease, a doctor will typically recommend blood tests before making any dietary changes and, if the result is positive, a biopsy to confirm the diagnosis.

Treatment for celiac disease in babies and children is the same for adults and requires a strictly gluten-free diet. While this may be challenging for the family, it is necessary at all times, without exception and must be continued for the rest of the person’s life to avoid complications. Support groups are available to assist families in adjusting to and managing a 100 percent gluten-free lifestyle.

Other names for celiac disease

  • Coeliac disease (UK spelling)
  • Celiac sprue
  • Non-tropical sprue
  • Gluten-sensitive enteropathy
  • Gluten intolerance (however, celiac disease is more serious than the mild sensitivity to gluten experienced by many people)

Celiac disease FAQs

Q: Is celiac disease genetic?
A: Yes. Celiac disease is said to be genetic, because it typically develops in people who carry genes called HLA-DQ2 and HLA-DQ8. These genes are found in about 30 percent of people. However, not everyone who has these genes will develop celiac disease; only about one in every 30 people will develop the condition. It is triggered by a combination of genes and environmental factors. If a close relative has celiac disease, a person’s likelihood of developing it is higher, and screening may be recommended. 5 2 26

Q: Is there a test for celiac disease?
A: Yes. There is a blood test that can detect the antibodies – proteins that typically fight infection – found in celiac disease. If the test is positive for these antibodies, diagnosis is typically confirmed with a biopsy, where a small sample of tissue is taken from the small intestine and checked in a laboratory. 1

Q: What is the difference between celiac disease and gluten sensitivity?
A: Some people who do not have celiac disease may nonetheless experience similar symptoms when eating foods containing gluten, and they may feel better when they exclude gluten from their diet. This is called non-celiac gluten sensitivity, or simply gluten sensitivity. 14

Q: What is the difference between celiac disease and a wheat allergy?
A: Celiac disease is a severe response to gluten, a type of protein which is found in wheat and many other grains. Eating foods containing gluten causes a long-term autoimmune reaction, where the body is attacked by its own immune system. Symptoms may not appear immediately. A wheat allergy, on the other hand, is an immediate, short-term reaction to proteins found in wheat specifically. Eating foods containing wheat or being exposed to wheat in other ways causes the immune system to try and attack these proteins as if they were invading germs. The immune system does not attack the body. The symptoms of celiac disease and wheat allergy are different. 27 28

Q: Is there a celiac disease vaccine?
A: Not yet. A vaccine for celiac disease is currently being researched and tested in clinical trials to see whether it works and whether it is safe for people to receive. It is called Nexvax2® and aims to desensitize people with celiac disease to gluten, so that it no longer triggers an autoimmune response. 29 30