Dermatitis herpetiformis (DH) is the skin manifestation of coeliac disease. It is less common than coeliac disease with a UK prevalence of 1 in 3,300 in the general population. DH can appear at any age, but is most commonly diagnosed in those aged between 50 and 69 years.
DH is characterised by red, raised patches, often with blisters that burst with scratching. DH is often seen symmetrically on the body, for example on both elbows or both knees.
Diagnosis of DH should be carried out by a dermatologist by taking a biopsy of a small sample of the skin from an area without the rash. People with DH should be referred to a gastroenterologist for endoscopy and biopsy. Most people with DH have damage to the lining of the gut, even though around 60% of people with DH do not have gut symptoms.
DH is managed by a gluten free diet and drug treatment may also be required. Once established on a gluten free diet it can often take several months before the rash improves and up to two years before it disappears completely. Both the skin disease and the intestinal disease return with the reintroduction of gluten to the diet.
Drugs, such as Dapsone (Diaminodiphenylsulfone), are important for managing DH. The skin symptoms in DH clear rapidly on treatment with Dapsone and can reappear rapidly if Dapsone is discontinued. Side effects of Dapsone include haemolytic anaemia, neuropathy, depression and headache.
Dapsone has no influence on intestinal abnormality. It is important to continue a gluten free diet alongside drug treatment.
Dr Teea Salmi provided an update on DH at our Research Conference, watch the presentation below.