Bullous pemphigoid

What is bullous pemphigoid?

Bullous pemphigoid is a skin condition that can cause a rash, itching and blisters.

There are several skin conditions which cause blisters. It is important to know exactly which disease you have as they have similar sounding names but vary greatly in their seriousness, outlook (prognosis) and treatment. For example, see the separate leaflet called Pemphigus Vulgaris (which is generally more serious than bullous pemphigoid).

Symptoms of bullous pemphigoid

Symptoms of bullous pemphigoid include:

• Areas of itchy skin.

• Pink rash which can look like eczema or urticaria.

• Firm and dome-shaped fluid-filled blisters.

• Small blisters inside the mouth or on the lips.

The itch or rash can develop weeks or months before the blisters appear.

Any area of skin can be affected, but blisters mostly occur on the arms, legs, armpits and groin. The amount of blistering can vary: sometimes it is just one area, such as the lower leg. In severe cases, the whole body may be affected.

This photo shows the typical blisters:

Bullous pemphigoid leg blisters

By Mohammad2018, CC BY-SA 4.0, via Wikimedia Commons

How common is bullous pemphigoid?

Bullous pemphigoid is rare. In the UK it is estimated that between 4-5 people in 100,000 develop it each year. Most people with bullous pemphigoid are aged over 70. It is very rare in children. It is not contagious so you cannot catch it from an affected person.

It can come on in pregnancy, when it is called gestational pemphigoid and requires careful management by a dermatologist and an obstetrician together.

What causes bullous pemphigoid?

Bullous pemphigoid is an autoimmune disease. The immune system normally makes antibodies to attack bacteria, viruses, and other germs. In people with bullous pemphigoid, the immune system makes antibodies against the basement membrane between the top layer of skin (the epidermis) and the next layer (the dermis). This causes fluid to build up as blisters between these two layers of skin.

It is not known what causes bullous pemphigoid. but certain conditions and medications may trigger it. They include:

• Diseases which involve the nervous system such as dementia and multiple sclerosis.

• Medications such as furosemide, non-steroidal anti-inflammatory drugs (NSAIDs), captopril, some diabetes medicines and some antibiotic medicines.

Can stress cause bullous pemphigoid?

There is no evidence that stress causes or triggers this condition.

How is bullous pemphigoid diagnosed?

The diagnosis may take a while as it may look like eczema or an allergy at first. There are also several conditions which can cause blisters. If your doctor suspects that you have bullous pemphigoid, they will refer you to a skin specialist. Tests are usually done to confirm the diagnosis. These are:

• A small sample (biopsy) of skin may be taken. This is looked at under the microscope and tested to confirm that the blisters are due to bullous pemphigoid.

• A blood test can detect the antibody that causes bullous pemphigoid (the bullous pemphigoid auto-antibody).

Bullous pemphigoid treatment

Treatment aims to improve your symptoms and avoid side effects.

Treatments used for bullous pemphigoid are:

Steroids

Steroids are the main treatment for bullous pemphigoid.

High-strength steroid creams, also called topical steroids (for example, clobetasol) will normally be needed.

Steroid tablets such as prednisolone are commonly used with or without steroid creams, especially if the rash is on more than one body area, or there are practical problems applying the cream. Steroids reduce inflammation and suppress the immune system.

Side-effects

All steroids can have side-effects. Side-effects from steroids can be serious, especially if you take high doses for a long time.

If you take steroid treatment for more than a month, you will usually be advised to take additional medications to reduce the risk of serious side effects. It is important not to stop steroids without discussing it with your doctor first. For more information see the separate leaflet called Oral Steroids.

Other drugs to calm the immune system may be used if you cannot use steroids or they are not working to control your condition.

Looking after your skin is important with this condition, and you may be advised to use certain creams or moisturisers to wash with, or apply to your skin to keep it in the best condition possible.

What is the outlook for bullous pemphigoid?

Bullous pemphigoid usually goes away after 3-6 years. Treatment can then be stopped. In some people the condition unfortunately persists.

Widespread or severe bullous pemphigoid is a serious condition. In addition to the side effects caused by the treatments, it can be fatal due to the risk of broken areas of skin developing a bacterial infection.