Bullous Pemphigoid

What is bullous pemphigoid?

Bullous pemphigoid is a skin condition that causes blisters. In some cases the condition becomes severe and serious.

Note: several skin conditions cause blisters and it is important to know exactly which disease you have. They have similar sounding names, for example, pemphigus vulgaris and other types of pemphigus. These different 'blistering' conditions vary greatly in their seriousness, outlook and treatment. See separate leaflet called 'Pemphigus Vulgaris' (which tends to be a more serious disease than bullous pemphigoid).

This leaflet is only about bullous pemphigoid (shortened to BP from now on).

Who gets bullous pemphigoid?

Bullous pemphigoid (BP) is rare. In the UK, it is estimated that between 7 and 40 people in a million develop it each year. Most people with BP are aged over 70. It is very rare in children. BP is not infectious and you cannot 'catch' it from an affected person.

What causes bullous pemphigoid?

BP is an auto-immune disease. The immune system normally makes antibodies to attack bacteria, viruses, and other 'germs'. In people with auto-immune diseases, the immune system also makes antibodies against part(s) of the body.

In people with BP, antibodies are made against the membrane between the top layer of skin (the epidermis) and the next layer (the dermis). This antibody attack causes fluid to build up as blisters between these two layers of skin.

It is not known why BP or other auto-immune diseases occur. It is thought that something triggers the immune system to attack the body's own tissues. Certain conditions and medications have been linked to BP, although they are not thought to cause it (they may be trigger factors). These are: diseases called ulcerative colitis and multiple sclerosis; medications such as furosemide, non-steroidal anti-inflammatory drugs (NSAIDs), captopril, penicillamine and some antibiotics; other factors such as ultraviolet radiation and radiotherapy.

What are the symptoms of bullous pemphigoid?

The first symptoms may be small patches of itchy skin. There may also be a pink rash which can look like eczema. Blisters then develop a week or more later. (In some cases, the blisters do not start until months later.)

The blisters are quite firm and dome-shaped. The blister fluid is usually clear, but may be cloudy or blood-stained. Any area of skin can be affected, but most often it is the arms, legs, armpits, and groin which have the blisters. 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.

The skin over the blisters is quite strong and may remain for several days before the blister bursts. A raw patch of skin is left when a blister bursts, which then heals. Some blisters do not burst, instead the fluid is absorbed into the body and the roof of the blister settles back down on the skin. The blisters heal without forming scars.

Some people with BP get small blisters inside the mouth. The blisters can break to form ‘erosions’ (like mouth ulcers).

BP may be itchy; the amount of itch can vary from severe to none at all.

How does bullous pemphigoid progress?

If untreated, the blisters and raw areas of skin can cause much discomfort. There is a danger of serious infection occurring on raw areas of skin.

BP commonly lasts 1-5 years and then often eases or goes away. Future recurrences may occur, but these tend to be milder.

How is bullous pemphigoid diagnosed?

The diagnosis may not be clear at first. There are other causes of skin blisters and mouth erosions. Also, the early symptoms (before blisters appear) may look like eczema or allergy. If your doctor suspects that you have BP, s/he will refer you to a skin specialist. Tests are usually done to confirm the diagnosis. These are:

• A biopsy (a small sample) of skin may be taken. This is looked at under the microscope and tested to confirm that the blisters are due to BP.
• A blood test can detect the antibody that causes BP (the BP auto-antibody). The antibody may also be detected in urine or in blister fluid.

What is the treatment of bullous pemphigoid?

Treatment involves suppressing the immune process, so that itching and blistering is reduced. The aim is to find the right balance of treatment, so that you feel comfortable and do not have many blisters, but without too many side-effects of treatment. Usually the best balance is the point where there may be a few blisters or symptoms which you can tolerate. This may be better than totally suppressing all symptoms, which could mean using large amounts of treatment and getting more side-effects. Treatments used for BP are:

Steroids

Steroid tablets such as prednisolone are the traditional treatment for BP. Steroids reduce inflammation and suppress the immune system. The dose of steroid depends on how severe the BP is. A medium or high dose is usually needed at first, and the dose can then be reduced once the blisters clear up. The aim is to find the lowest dose needed to control symptoms, which varies from person to person. (In the past, very high doses of steroids were sometimes used; nowadays, doctors think that such high doses are not necessary.)

Steroid creams, also called 'topical steroids' are an alternative to steroid tablets. High strength steroid creams will normally be needed. The creams are a good option if you have only a small area of blisters. Also, recent research suggests that steroid creams are a good option for most types of BP, even the more severe forms. This recent research suggests that certain steroid creams are more effective than steroid tablets, have fewer side-effects and give better results overall.

Steroid creams and tablets can be used together, and this may mean that a lower dose of tablets can be used.

All steroids, whether tablets or creams, can have side-effects. Side-effects from steroids can sometimes be serious, especially if you take high dose steroids for a long time. For example, you are more prone to certain infections if you take regular high dose steroids. Another side-effect is osteoporosis (thinning of the bones). If starting steroid treatment for BP, you will probably be advised to take vitamin D and calcium tablets to help prevent osteoporosis, and possibly other preventative treatment as well. Also be aware that long-term steroid treatment should not be stopped suddenly. See separate leaflets called 'Steroid Tablets' and 'Osteoporosis' for more details.

Other treatments

There are some other treatments which can help with BP. These are:

• Skin treatments such as dressings and wound care will be needed if you have areas of raw skin.
• An antibiotic (tetracycline) combined with another tablet (nicotinamide) can work well for BP which is mild or moderate. They can be the first choice treatment for this type of BP.
• Immunosuppressants such as azathioprine, methotrexate, mycophenolate mofetil or others. These work by suppressing the immune system. The dose of steroid needed may be less if you take an immunosuppressant. This means that any side-effects from steroids may be less severe.
• Other treatments which have been tried are: dapsone, antibiotics (erythromycin or sulphonamides), intravenous immunoglobulin and plasmapheresis. These have helped some patients. As with immunosuppressants, they may help to reduce the amount of steroids that you need.

What is the outlook (prognosis)?

The outlook is generally good. BP often goes away after 1-5 years, and meanwhile, treatment usually keeps the blisters away. Often, treatment can be stopped after about 1-5 years, as it is no longer needed. However, BP can sometimes cause serious illness which may cause death. This is because:

• Serious infection of raw skin is a danger. BP most commonly affects elderly people who are more prone to develop serious illness if a skin infection occurs.
• Side-effects from steroids and immunosuppressant medication may be a problem and can sometimes be serious.

Further help and information

Bullous Pemphigoid Support Group

17 Barley Mount, Redhills, Exeter EX4 1RP
Tel: 01392 431362 (evenings)

The International Pemphigus Foundation

Provides information about both pemphigus and bullous pemphigoid.
www.pemphigus.org

Dermnet NZ

Has information about skin conditions including bullous pemphigoid, with pictures.
Web: www.dermnetnz.org