Dermatitis herpetiformis is a skin rash that develops as a result of gluten sensitivity.
The National Organization for Rare Disorders (NORD) consider dermatitis herpetiformis, or DH, a rare disease. It appears to affect people aged 30–40 years and rarely affects children. Men are at a slightly higher risk than women.
This article will discuss the symptoms, causes, and treatment of DH, and how it relates to celiac disease.
The symptoms of DH vary for different people, so not everyone may experience all symptoms. Typically, it affects three areas of the body — the skin, the gastrointestinal (GI) tract, and the mouth.
The most common effects of DH appear on the skin, with symptoms such as itchy blisters and raised clusters of lesions.
Commonly, areas that DH affects include elbows, knees, buttocks, and scalp. It may also affect the face and groin.
Many people feel an intense need to scratch itchy or burning areas.
The GI tract
Stomach inflammation and damage to the small intestine are common reactions in people with gluten sensitivity. These reactions usually develop a few days after a person ingests gluten.
People with DH may notice uncomfortable symptoms such as:
Some people develop problems with their tooth enamel, for example, horizontal grooves or discoloration.
Rarely, DH can also lead to oral ulcerations and canker sores.
Although doctors still do not fully understand the causes of DH, genetics and lifestyle factors are likely to play a role.
For a long time, doctors did not know the cause of this skin rash, which made the condition challenging to manage. Experts then observed that DH symptoms reduced considerably in people who altered their diets to include little to no gluten.
This observation led to the discovery that DH has a strong association with gluten sensitivity. Gluten is a protein in grains that include wheat, rye, and barley.
Examples of foods that contain gluten are:
- baked goods
Some studies show that close relatives of people with DH are at an increased risk of developing the condition themselves.
To diagnose the cause of a skin rash, doctors will usually take a skin scraping or a skin biopsy. These tests involve a doctor obtaining a small sample of skin to send off to a laboratory for examination.
A doctor may also recommend an intestinal biopsy, especially in people who show signs of gastrointestinal problems.
When a skin biopsy cannot confirm or rule out DH, doctors may recommend blood tests that search for antibodies called anti-gliadin, anti-reticulin, and anti-endomysial antibodies.
A strict gluten-free diet is the most effective treatment option for people with DH. A registered dietician can help identify and eliminate both obvious and hidden sources of dietary gluten and recommend alternatives for the short- and long-term.
Doctors often prescribe a medicine called dapsone to provide immediate relief from symptoms.
Some people, however, cannot tolerate dapsone treatment. These individuals can instead take other forms of medication that contain substances called sulfapyridine or sulfamethoxypyridazine.
People may continue to take this medication for anywhere between a few months to 2 years. After this, DH can go into remission. Remission is when a person has no symptoms for more than 2 years while not using medication or a special diet.
People may mistake DH for other conditions with similar symptoms, including:
- Eczema: Also known as atopic dermatitis, eczema is a group of skin conditions that cause skin inflammation or irritation. Common symptoms include dry skin, rashes, and itching, especially on the arms and behind the knees.
- Scabies: Scabies is a skin condition caused by a mite infestation. It is highly contagious and spreads by direct skin contact.
- Linear IgA disease: This disease is a rare and often long-term skin problem the characteristics of which are groups of itchy blisters and raised lesions on the skin. It is an autoimmune disease that certain medications can trigger.
DH is a long-term, chronic condition and tends to persist lifelong in most people.
People can control their symptoms with a combination of dapsone treatment and a gluten-free diet. After several years, the condition can go into remission.
People with DH can manage their condition by ensuring regular medical checkups and guidance from a specialist skin doctor, called a dermatologist, and a nutritionist.