COELIAC DISEASE
Coeliac disease is a condition in which there is sensitivity to gluten,
a component of wheat and some other dietary proteins. Exposure to foods
containing wheat causes damage to the small intestine and so interferes
with the normal absorption of food. Coeliac disease is a permanent condition
and has to be differentiated from the more common problem of transient
gluten intolerance.
Symptoms.
These are very variable and range from virtually none at all to life-threatening
illness. Coeliac disease most commonly presents in childhood soon after
the introduction of wheat products to the diet but it may become apparent
at any age and, especially if the symptoms are mild, may go unrecognised
for many years. The most characteristic symptom is the passage of frequent,
large, loose, pale and smelly stools which may look greasy and be difficult
to flush; this is due to a high fat content resulting from reduced absorption
of fat from the diet. This in turn reduces the absorption of essential
nutrients and energy. Affected infants may 'fail to thrive' (grow and gain
weight too slowly) and older children show delay in growth and puberty;
they lack fat and muscle yet typically have a prominent abdomen due to
excess air in the gut and poor muscle tone. Children with coeliac disease
also tend to be irritable and unhappy. Eventually they become pale and
tired from anaemia and lack of muscle bulk and strength. They may even
develop rickets from lack of vitamin D, which is fat- soluble, and sometimes
other late complications.
Diagnosis.
The key test for the diagnosis of coeliac disease is a jejunal biopsy.
This entails microscopic examination of a tiny piece of the lining of the
upper small gut (duodenum or jejunum) taken through an endoscope (a telescopic
instrument passed through the mouth). The appearance of the gut wall is
characteristic with complete flattening of the normal finger-like processes
which line the absorptive surface. This is an invasive test with potential
complications and in children requires an anaesthetic or heavy sedation.
Fortunately, the diagnosis can now be made with a considerable degree of
confidence from blood tests which detect the presence of antibodies to
gluten. There are differing views on whether all children should have a
biopsy to confirm the diagnosis. If a trial of a gluten free diet is planned
anyway, a biopsy may not be essential beforehand but it is then vital at
some time to review the continuing need for a gluten free diet in case
the problem may have been transient. This is usually done with a 'gluten
challenge' (see separate sheet). A biopsy is needed before any patient
is committed to a lifelong gluten-free diet. .
Cause.
In spite of a great deal of research, the cause of coeliac disease remains
obscure. There is a strong genetic element with an incidence of around
10% in close relatives of affected patients. The disease is much more common
in some parts of the world, such as Ireland, than others. The major theories
on the cause implicate either a biochemical or an immunological deficit
or both. In recent years the frequency of the disease seems to have fallen,
possibly because of the later introduction of cereal into the diet of babies.
Treatment.
This requires a strict gluten free diet; most patients with coeliac
disease have to avoid not only wheat but also rye and barley; some can
tolerate oats but others cannot; all can tolerate rice and maize. This
is not an easy diet to follow and continual vigilance is needed to avoid
exposure to wheat products in prepared foods. The advice of a dietician
with experience of the condition is therefore needed. A wide variety of
gluten free products is now available commercially and GPs can prescribe
many of these. It is recommended that families with affected members keep
in touch with the Coeliac Society which, among many other services, provides
a source of up to date information on all aspects of the condition.
Outlook.
Children with coeliac disease usually show a dramatic response to a
gluten free diet. Within days their mood has changed and all the symptoms
and secondary effects of the disease rapidly correct. Minor lapses in the
diet are generally well-tolerated but some children get brisk diarrhoea
and vomiting after any exposure at all. On a strict diet the long-term
outlook is good with the expectation of normal health, normal fertility
and a normal lifespan. Further understanding of the disease and progress
towards a cure seem very likely in the near future. |
