Dermatitis herpetiformis is an autoimmune disorder that causes a chronic and very itchy rash, usually on the elbows, knees, and buttocks, although it can affect any area of the skin.

The name “herpetiformis” often creates confusion and people tend to think that the condition is caused by the herpes simplex virus. However, the name herpetiformis is used because the skin lesions that develop in this disorder often resemble those seen in herpes-related infections, and not because dermatitis herpetiformis is caused by the herpes virus.

Causes

Dermatitis herpetiformis is strongly associated with celiac disease, an autoimmune disorder that occurs in response to eating gluten and causes the small intestine to become inflamed.

People who develop dermatitis herpetiformis are also sensitive to gluten and around one quarter of individuals who have celiac disease also develop this skin rash. There is a hereditary aspect to dermatitis herpetiformis, with 10% of sufferers having a family history of the condition.

Herpes, on the other hand, is a commonly seen skin infection caused by the herpes simplex virus.

Symptoms of herpes infection are skin redness, temperature, soreness and blisters in the lips, mouth or other areas of the skin, and swollen lymph glands. It can be transmitted from one person to another via physical contact.

The virus can remain dormant for years and become active again causing rashes on the skin. Herpes commonly affects the lips and genital areas.

In both herpes and dermatitis herpetiformis, the lesions arise in small groups. In the case of herpes, symptoms may go away on their own in a few days or weeks but the virus remains dormant in the patient’s body.

In rare cases, the infection recurs and needs to be treated with anti-virals and some lifestyle changes. Other infections such as flu or cold, exhaustion, skin injuries, or sunburn can promote the virus’ activity.

Dermatitis herpetiformis usually affects people aged 20 or older, although in some cases, onset occurs in childhood. It affects both men and women, though men are slightly more susceptible than women.

In contrast, primary herpes infections occur in infants and young children, especially in underdeveloped countries. Type 2 herpes infections are mostly sexually transmitted and occur after puberty.

Symptoms

The first sign that a skin rash may be dermatitis herpetiformis is that it is extremely itchy. By the time a patient does seek help, the blisters that form are usually broken due to the patient scratching  them.

The rash is usually seen on the elbows, knees or buttocks  in a bilateral, symmetrical fashion, with the rash forming on both sides of the body.

Once a person is diagnosed with dermatitis herpetiformis, symptoms can usually be relieved with appropriate treatment and by sticking to a diet that is free of gluten.

Primary infections of herpes simplex, on the other hand, are usually mild in children aged 1 and 5 years causing fever and restlessness.

Swollen and bleeding gums and painful swallowing are some other symptoms that can be present. Yellowish ulcers can also be found on throat, tongue, and inside of cheeks. Type 1 herpes is called oral herpes and typically affects the mouth, tongue and lips. Type 2 herpes is called genital herpes and affects genital areas.

Treatment

Dermatitis herpetiformis can be managed with antibiotics such as dapsone, which can lead to dramatic improvement within 48 to 72 hours.

Alternative antibiotics that may be used include sulfapyridine or sulfamethoxypyridazine. However, the underlying celiac disease can only be treated through adherence to a gluten-free diet for a long term.

In the case of herpes, mild infections often need no treatment. Severe infections need to be treated with antiviral drugs such as acyclovir, valaciclovir, and famciclovir.