Coeliac disease

Coeliac disease, also known as celiac disease, is a common bowel condition that is caused by intolerance to a protein called gluten. Gluten is found in wheat, rye, and barley, which are often used to make foods such as bread, pasta, and biscuits.

What causes coeliac disease?

The exact cause of coeliac disease is unknown; however, the condition can be inherited (run in families).

Although it is linked to certain foods, coeliac disease is not a food allergy. It is an autoimmune condition, which means that it occurs as a result of the body's immune system attacking gluten in the digestive system.

In people with coeliac disease, their immune system mistakes gluten as being harmful and attacks it, damaging the lining of the intestines (gut) so that it cannot absorb food properly. This leads to symptoms such as diarrhoea, weight loss, and stomach pain.

Who gets coeliac disease?

Coeliac disease affects approximately 1% of people in the UK. However, some people with the condition may have few, or no, symptoms. Many people may also have the condition but be unaware of it.

Anyone can develop coeliac disease at any age, including babies and children, although it is most common among those who are between 40-50 years of age.

There is no cure for coeliac disease, but the symptoms can be kept under control by using a strict gluten-free diet. However, coeliac disease that is untreated, or undiagnosed, can cause several different complications.

The symptoms of coeliac disease vary from person to person, and the condition affects babies and children differently to the way in which it affects adults. However, some people who have coeliac disease may never develop symptoms.

The various symptoms of coeliac disease in babies, children, and adults are described below.

Symptoms of coeliac disease in babies

If your baby has coeliac disease, the symptoms will first appear soon after foods containing gluten are introduced into their diet, such as cereals and bread.

Your baby's symptoms may include:

• bulky and pale stools (faeces),
• smelly diarrhoea,
• vomiting,
• a swollen stomach, and
• failure to grow and gain weight.

Symptoms of coeliac disease in children

The symptoms of coeliac disease in children are similar to those that affect babies with the condition. If your child has coeliac disease, they may have symptoms such as:

• poor growth,
• pale, smelly, oily stools (faeces) that may be difficult to flush away,
• diarrhoea, and
• anaemia (tiredness, breathlessness, and an irregular heart beat, caused by a lack of iron in the blood).

Your child may develop anaemia because they cannot absorb enough vitamins and minerals, such as iron, from the food they eat. This is due to the damage in their digestive system caused by gluten intolerance.

Symptoms of coeliac disease in adults

If you have coeliac disease, your symptoms may include:

• stomach pain (which may come and go),
• excess flatulence (breaking wind),
• feeling bloated,
• diarrhoea,
• tiredness, or weakness,
• mouth ulcers,
• weight loss, and
• anaemia (tiredness, breathlessness, and an irregular heart beat, caused by a lack of iron in the blood).

As is the case in children, due to the damage to your digestive system, caused by gluten, you may develop anaemia alongside coeliac disease. This damage means that you cannot absorb enough vitamins and minerals, such as iron, from your food.

Dermatitis herpetiformis

Although it is not actually a symptom of coeliac disease, if you have an intolerance to gluten, you may also develop a type of skin rash, known as dermatitis herpetiformis. If you have coeliac disease, you may or may not also have dermatitis herpetiformis.

If you have dermatitis herpetiformis, you will have an itchy, stinging rash, with blisters that may burst when you scratch them. The rash usually appears on your elbows, knees, and buttocks, although it can appear anywhere on your body.

How does coeliac disease occur?

Coeliac disease is caused by an intolerance to gluten, a protein that is found in foods such as bread, pasta, cereals, and biscuits. Some people with the condition find that eating oats can also trigger their symptoms.

If you have coeliac disease, any gluten that you eat is attacked by your immune system when it reaches your intestines (gut). This happens because coeliac disease is an autoimmune condition, in which your immune system mistakes gluten for a harmful substance and produces antibodies against it. Antibodies usually fight off harmful foreign bodies, such as bacteria and viruses.

When the antibodies attack gluten, they can also damage the lining of your gut, causing inflammation. Normally, the surface of the gut lining is covered with millions of tiny tube-shaped growths called villi, which increase the surface area of your gut, helping it to digest food more effectively. However, in coeliac disease, the damage and inflammation to the lining of your gut flattens the villi, reducing their ability to aid digestion.

As a result of this, your gut can no longer digest all of the nutrients that you need from the food you eat. This leads to the symptoms of coeliac disease, including diarrhoea and weight loss.

Why does coeliac disease occur?

The exact reason why coeliac disease occurs is not fully understood and, in some cases, it may not be possible to identify a cause at all. It is possible to develop an intolerance to gluten at any point in your life, for no apparent reason.

However, several possible causes of coeliac disease have been identified and are outlined below.

Family history

Coeliac disease can be inherited and often runs in families. If you have a close relative with the condition, such as a parent, sibling (brother or sister), or child, you have an increased risk of also developing it. This increased risk is approximately 10%, compared with 1% for those who do not have a close relative with coeliac disease.

Other conditions

You are more likely to develop coeliac disease if you have certain conditions, including Type 1 diabetes (insulin-dependent), or an under-active thyroid (hypothyroidism).

As with coeliac disease, this may be because these conditions are also caused by an autoimmune reaction. Type 1 diabetes occurs when your immune system attacks cells in your pancreas that produce insulin, and hypothyroidism commonly occurs when your immune system targets your thyroid gland.

Coeliac disease is also more common among people who have osteoporosis (weak and brittle bones) or ulcerative colitis (inflammation and ulcers in the large intestine).

Stress or trauma

In some cases, it is thought that coeliac disease may be brought on by severe stress, although the reason for this is unknown.

Similarly, you may have an increased risk of developing coeliac disease after a stressful event, or a trauma on your body. For example, it is possible for people to develop coeliac disease after an infection or injury, after surgery, or after pregnancy.

See your GP if you think that you, or your child, may have coeliac disease.

However, it is very important that you do not cut gluten out of your or your child's, diet before a positive diagnosis has been made. Doing so could mean that the results of any tests that you have may not be accurate.

You should continue to eat your normal diet, including any foods that contain gluten, such as bread and pasta. If you have already stopped eating gluten, you will need to start eating it again for at least six weeks before a diagnosis of coeliac disease can be confirmed.

In order to be diagnosed with coeliac disease, you will need to have two tests - a blood test and a gut biopsy.

Blood test

Your GP will take a sample of your blood and test it for certain antibodies that are usually present in the bloodstream of people with coeliac disease. However, it is possible to have coeliac disease and not have these antibodies in your blood.

If coeliac disease antibodies are found in your blood, your GP will refer you for a biopsy of your gut.

The symptoms of coeliac disease can appear to be similar to those of other digestive conditions, such as irritable bowel syndrome (IBS), and Crohn's disease (a disease of the small intestine). For this reason, you will not usually be referred for a gut biopsy unless you have coeliac disease antibodies in your blood.

Gut biopsy

A gut biopsy is carried out in hospital, usually by a gastroenterologist (a specialist in conditions of the stomach and intestines). It can confirm a diagnosis of coeliac disease.

If you need to have a gut biopsy, a thin flexible tube with a light and a tiny cutting tool on the end (an endoscope) will be inserted into your mouth and gently fed down to your small intestine. Before the procedure, you will be given a local anaesthetic and a sedative to numb your throat and to help relax you.

The gastroenterologist will use the endoscope to cut away a small tissue sample from your small intestine. This sample will later be examined for signs of coeliac disease.

Tests after diagnosis

If you are diagnosed with coeliac disease, you may also have a number of other tests to assess how the condition has so far affected you.

You may have further blood tests to check the levels of iron and other vitamins and minerals in your bloodstream. This will show whether or not coeliac disease has caused you to develop anaemia (a condition where there is a lack of iron in the blood) due to poor digestion.

If you appear to have dermatitis herpetiformis (an itchy rash also caused by gluten intolerance), you may have a skin biopsy in order to confirm it. This is carried out in a similar way to a gut biopsy; where a small sample of skin is taken from an area unaffected by the rash so that it can be examined.

In some cases, you may also need to have a DEXA scan, which is a type of X-ray that measures your bone density. This may be necessary if your GP thinks that your condition may have started to damage your bones, which can result in osteoporosis (weak and brittle bones). In coeliac disease, a lack of nutrients, caused by poor digestion, can make your bones become weaker and less dense.

Simply excluding gluten and any foods that contain gluten, from your diet is usually how coeliac disease is treated. This prevents the damage to the lining of your intestines (gut) that is caused by gluten, and the associated symptoms, such as diarrhoea and stomach pain.

If you have coeliac disease, you must give up all sources of gluten for life because eating foods that contain it will cause your symptoms to return. This can be a daunting prospect, but your GP will be able to provide you with help and advice about ways that you can manage your diet.

Your symptoms should improve considerably within weeks of starting a gluten-free diet. However, it may take up to two years for your digestive system to heal completely. You will also need to return to your GP for check-ups on a regular basis.

A gluten-free diet

When you are first diagnosed with coeliac disease, you will be referred to a dietician who will be able to help you adjust to your new diet without gluten. They can also ensure that your diet is balanced, and contains all the nutrients that you need, including essential vitamins and minerals.

If you have coeliac disease, you will no longer be able to eat any foods that contain wheat, (farina, graham flour, semolina and durum), barley, or rye.

However, gluten as a protein is not essential to your diet and can be replaced by other foods. There are many gluten-free alternatives that are widely available in supermarkets and health food shops, including pasta, pizza bases, and bread. You may be able to get these gluten-free foods on prescription.

There are also many basic foods that are naturally free from gluten, which you can still include in your diet, such as meat, vegetables, cheese, and rice.

Your dietician will be able to help you identify which foods are safe to eat and which are not. However, if you are unsure, lists below provide a general guide.

Foods to avoid (containing gluten)

Unless they are labelled as gluten-free, and you have coeliac disease, you should not eat:

• bread,
• pasta,
• cereals,
• biscuits, or crackers,
• cakes and pastries,
• pies,
• gravies and sauces, or
• oats (although some people with coeliac disease may be able to eat foods containing oats, it is best to avoid them because they can often be contaminated with wheat).

It is important that you always check the labels of any foods that you buy. Many foods, particularly those that are processed, contain gluten in food additives, such as malt flavouring, and modified food starch. Gluten may also be found in some non-food items, including lipstick, postage stamps, and some types of medication.

You should also be aware that cross-contamination can occur if gluten-free foods and foods containing gluten are prepared together, or served with the same utensils.

Foods to include (gluten-free)

If you have coeliac disease, you may eat the following gluten-free foods:

• most dairy products, such as cheese, butter and milk,
• fruit,
• vegetables,
• meat and fish (although not breaded, or marinated),
• potatoes,
• rice, and
• gluten-free flours, including rice, corn, soy, and potato.

Other treatments for coeliac disease

Immunisations

If you have coeliac disease, it can cause your spleen to work less effectively, making you more vulnerable to infection from certain germs.

Therefore, you may need to have several immunisations including:

• the flu (influenza) jab,
• the HIB vaccine - which protects against blood poisoning, pneumonia, and HIB meningitis), and
• the pneumococcal vaccine - which protects against infections caused by the bacterium Streptococcus pneumoniae.

Supplements

As well as cutting gluten out of your diet, your GP, or dietician, may also recommend that you take vitamin and mineral supplements, at least for the first six months after your diagnosis.

This will ensure that you get all of the nutrients that you need while your digestive system is repairing itself. Taking supplements can also help to correct any deficiencies, such as anaemia, which is a condition that is caused by a lack of iron in the blood.

Treatment for dermatitis herpetiformis

If you have dermatitis herpetiformis (an itchy rash that is sometimes caused by gluten intolerance), cutting gluten out of your diet may be enough to clear it. However, it can take longer for a gluten-free diet to clear the rash than it does to control your other symptoms, such as diarrhoea and stomach pain.

If this is the case, you may be prescribed medication to speed up the healing time of the rash. It is likely that this will be a medicine called Dapsone, which is usually taken in tablet form, twice a day. As Dapsone can cause side effects, such as headaches and depression, you will always be prescribed the lowest effective dose.

You may need to take medication for up to two years in order to control your dermatitis herpetiformis. After this time, you should have been following a gluten-free diet long enough to control the rash without the need for medication.

If you have coeliac disease that is untreated, or undiagnosed, (you are still eating gluten), several complications can occur. Therefore, if you have coeliac disease, it is crucial that you do not eat any gluten at all.

It is a common misconception that eating a little bit of gluten will not do you any harm. However, eating even tiny amounts of gluten can cause the symptoms of coeliac disease, and increase your risk of developing the complications outlined below.

Osteoporosis

Osteoporosis is a condition that causes your bones to become brittle and weak. Your bones need a wide variety of vitamins and minerals in order to stay dense and strong.

If you have coeliac disease, you have an increased risk of developing osteoporosis due to the effect on your digestion. The damage gluten causes to your intestines (gut) prevents enough nutrients being absorbed into your bones from the food you eat.

Malnutrition

As coeliac disease causes your digestive system to work less effectively, it can lead to a severe lack of nutrients in your body. This is known as malnutrition, and means that your body cannot function normally, or recover from wounds, or infections.

If you have severe malnutrition, you may become fatigued, dizzy, and confused. Your muscles may begin to waste away, and you may find it difficult to keep warm. In children, malnutrition can cause stunted growth and delayed development.

Lactose intolerance

If you have coeliac disease, you are more likely to also develop lactose intolerance, which is a reaction to milk sugar (lactose) found in dairy products. Lactose intolerance causes symptoms such as bloating and abdominal discomfort. The damage to your digestive system, caused by gluten, may also make it difficult for you to digest lactose.

Cancer of the bowel

Some research has suggested that having coeliac disease can increase your risk of developing bowel cancer, or gut lymphoma (a type of cancer that occurs in white blood cells). However, there is also conflicting research that disagrees with this, and suggests that there is no increased risk for people with coeliac disease.

Research also suggests that any increased risk of bowel cancer may return to normal within 3-5 years of following a gluten-free diet. After this time, it is thought that any increased risk of bowel cancer, for those with coeliac disease, decreases and becomes equal to that of a person without the condition.

Whether you have coeliac disease or not, it is important to be aware of the symptoms of bowel cancer, which include bloody or black stools (faeces), weight loss, and abdominal pain. See your GP if you develop these symptoms.

British Nutrition Foundation. (2000). Food Allergy and Intolerance [online] (Accessed 8th April 2008).

Coeliac UK. (2008). Coeliac disease [online] (Accessed 8th April 2008) (whole section).

Hicks, R. (2008). Coeliac disease [online] BBC Health. (Accessed 8th April 2008).

Mayoclinic. (2006). Celiac disease [online] (Accessed 9th April 2008) (whole section).

NHS Immunisation Information. (2007). Vaccines > Hib/Men C > The diseases [online] (Accessed 10th April 2008).

NHS immunisation Information. (2007). Vaccines > Pneumococcal > The disease [online] (Accessed 10th April 2008).

Patient Plus. (2007). Dermatitis Herpetiformis [online] (Accessed 10th April 2008).

Patient Plus. (2007). Malnutrition [online] (Accessed 10th April 2008).

Patient UK. (2008). Coeliac Disease [online] (Accessed 8th April 2008).