HOW IS COELIAC DISEASE DIAGNOSED?

Blood tests for antibodies against alpha-gliadin (AGA), endomysial antibody (EmA) or tissue transglutaminase (tTG) are helpful in screening for coeliac disease, but are insufficient to make a definite diagnosis.

The only way to diagnose coeliac disease properly is by taking a sample (biopsy) of tissue from the lining of the small intestine (usually the duodenum, sometimes the jejunum) for examination under the microscope. The standard way to take the biopsy is through a gastroscope.

The procedure of upper gastro-intestinal endoscopy (or oesophagogastroduodenoscopy, OGD) is usually carried out as an outpatient. An OGD and biopsy takes about 10-15 minutes (excluding waiting times!). To confirm the diagnosis correctly, a biopsy is taken when on a normal (gluten-containing) diet and may be repeated after a period of gluten exclusion to make sure that the initial abnormalities are responding to treatment. It may take over a year for the gut lining to recover completely on a gluten-free diet.

DERMATITIS HERPETIFORMIS

Dermatitis Herpetiformis (DH) is a very itchy skin rash. It usually effects the outer aspects of the elbow and the knees, across the shoulders and over the buttocks. In very severe cases the rash may be more widespread, and in mild cases confined to the elbows or shoulders alone.

( See dermatitis herpetiformis picture )

Each little spot goes through four stages:
1. A small itchy flat red patch about 2-3mm in diameter
2. The flat area becomes thickened and a bump develops above the level of the surrounding normal skin.
3. The centre of the bump degenerates and fills with a clear pale yellow fluid (looks like a tiny water blister).
4. The fluid is absorbed and a tiny scar is left in the skin.

Stage 3 is not often seen, as the sufferer has usually scratched the spot so much that the surface is broken and the fluid is never able to collect in the blister.
The little blisters look like the rash of Chicken Pox and Shingles, but unlike these two conditions DH is neither infective or contagious. In Chicken Pox and shingles a virus causes the problem and the latin name for the virus is Varicella/Herpes Zoster virus. When doctors started naming rashes they used latin words. The term dermatitis herpetiformis means a skin problem (DERMATITIS) which looks like Chicken Pox (HERPETIFORMIS).

DERMATITIS HERPETIFORMIS AND COELIAC DISEASE

There is a strong link between DH and Coeliac Disease. It has been discovered that over half of all patients with DH have the same intestinal abnormality with damage to the villi on biopsy as do coeliacs. In a further third of the remaining patients there are signs of slight damage to the intestinal biopsy. The gut abnormality whether slight or more severe corrects itself when gluten is excluded from the diet.

DERMATITIS HERPETIFORMIS TREATMENT

In the vast majority of patients the skin rash responds dramatically within 12-48 hours of treatment with dapsone tablets, but unfortunately when this treatment is stopped the itch and the rash tend to reappear.
All DH patients with intestinal damage respond to treatment with a gluten free diet. Over a period of weeks or months the dose of dapsone required to control the rash may be decreased and in the majority of patients eventually no tablets are required. Even those patients with no signs of inflammation in the intestine benefit from gluten free diet. It is thought that the skin damage is something to do with gluten antibodies. As with coeliac disease the diet has to be continued for life or the intestinal damage will recur and the skin rash relapse

COLUMBIA GENETIC STUDY

The Columbia Genome Center, in conjunction with Dr. Peter Green of the Department of Medicine, Columbia-Presbyterian Medical Center, is conducting a research program at the Columbia University College of Physicians and Surgeons to identify the gene responsible for Celiac Disease. Professor of Genetics and Development, T. Conrad Gilliam, renowned for mapping the genes responsible for Wilson disease and Spinal Muscular Atrophy, is leading the investigation. The key to this type of study is the participation of families in which there are at least two family members affected with Celiac Disease.

Participation of unaffected, as well as affected family members, may be needed. Those individuals who consent to participate will be asked to provide a sample of blood for DNA analysis and give permission for release of their diagnostic record. Blood mailing kits with instruction can be mailed directly to family members. The blood can be drawn by a local physician or laboratory and mailed directly to the Genome Center at no cost to the individual. All interested persons who have at least two biopsy-proven family members with Celiac Disease should contact the Genetic Coordinator, Michele Pallai, at (203) 438-3582, or E-mail: celiac@genome3.columbia.cpmc.edu.