Dermatitis herpetiformis

Dermatitis herpetiformis, or 'DH', is a skin condition caused by gluten intolerance. It affects fewer people than coeliac disease - around one in 10,000. It can appear at any age but is most commonly diagnosed in those aged 15 - 40.

Symptoms are:

• Red, raised patches, often with blisters that burst with scratching
• Severe itching and often stinging 
• A rash which most commonly occurs on the elbows, knees and buttocks but can affect any area of the skin.
  

How is it diagnosed?

Confirmation of a diagnosis is made by a simple skin biopsy. A dermatologist (skin specialist) takes a small sample of skin from an unaffected area. This is checked for presence of the  'IgA'  (Immunoglobulin A). Antibody blood tests, or a small intestinal biopsy - the same tests used for diagnosing coeliac disease - should also be considered and the dermatologist will ask a gastroenterologist to arrange the biopsy. Even though they may not have gut symptoms, most people with dermatitis herpetiformis have gut inflammation.

How is it treated?

Although a gluten-free diet is the main form of treatment, and the most effective in the long term, it will not work immediately as it does for gut symptoms associated with coeliac disease. Consequently, drug treatment may be necessary. This will control the rash within days, though it will reappear if the drugs are discontinued before a gluten-free diet has taken effect.

It can take at least six months before the dose of drugs can be reduced and approximately two years before they can be discontinued completely. The most commonly prescribed drug for this condition is Dapsone.
It is essential to find the lowest effective dose of drug, as side effects are relatively common and can include a form of anaemia, nerve damage, depression and headache.

It is important to realise, too, that Dapsone will not benefit other problems caused by gluten sensitivity that the patient with DH might have, such as villous atrophy, anaemia or osteoporosis. A gluten-free diet is, therefore, an important part of treatment, as it is for any coeliac patient.

Does this condition increase other risks?

Any possibility of complications is reduced once a gluten-free diet has been established and adhered to. The same complications occur in DH as in coeliac disease, which include osteoporosis, gut cancer and an increased risk of other autoimmune diseases such as thyroid disease.

Further information is available free to members (join here) or you can buy information on related conditions  at our shop.