Medicines for Dermatitis herpetiformis

What it is

Dermatitis herpetiformis is an intensely itchy, blistering skin rash that is closely linked to coeliac disease — in fact, it is considered the skin manifestation of coeliac disease (the same immune reaction to gluten, a protein in wheat, barley and rye). It causes clusters of very itchy small blisters and raised red or discoloured bumps, often symmetrically on areas such as the elbows, knees, buttocks, back, and scalp. The itching and burning are typically severe, and because of the intense itch, the blisters are often scratched and broken, so what is seen may be scratch marks, crusts and scabs rather than intact blisters. Most people with dermatitis herpetiformis have the underlying gut changes of coeliac disease, even if they have few or no digestive symptoms — so the rash can be the main clue to coeliac disease. It tends to be a long-term condition that flares and settles. It is diagnosed by a skin biopsy (with specific tests) and by assessing for coeliac disease. Because it is driven by gluten, the key to controlling it — and to protecting long-term health, given the link with coeliac disease — is a gluten-free diet.

How it is treated

Management has two main parts: a strict, lifelong gluten-free diet, and, usually, a specific medicine to control the rash. The gluten-free diet is the cornerstone and the treatment that addresses the underlying cause — because dermatitis herpetiformis is driven by gluten (as in coeliac disease), removing gluten from the diet gradually clears the rash and, importantly, treats the associated coeliac disease and its long-term health implications; this is a lifelong dietary change, ideally with support from a dietitian, and it can take many months for the diet alone to fully control the skin. Because the diet takes time to work and the itching is severe, a specific medicine (dapsone) is often used as well, which typically controls the itching and rash quite quickly and provides relief while the gluten-free diet takes effect; it is then often reduced or stopped over time as the diet controls the condition, though some people need it longer, and it requires monitoring. Confirming and managing the associated coeliac disease (including monitoring for its complications and nutritional aspects) is an important part of care. The reassuring message is that dermatitis herpetiformis is very treatable — a strict gluten-free diet controls it and addresses the underlying coeliac disease, and a specific medicine gives quicker relief from the intense itch while the diet takes effect.