Reproduced, in part from the NHS website http://www.nhs.uk/conditions/bullous-pemphigoid/Pages/bullous-pemphigoid.aspx
BP is the most common immunobullous disease in Western Europe with a reported incidence of 43 per million per year in the U.K. It is a blistering skin disease that tends to affect the elderly.
As with the other blistering diseases mentioned here, it is caused by a problem with the immune system. It usually goes away on its own within a few years and, in the meantime, blisters can be controlled with medication.
About one in 10,000 people are affected by bullous pemphigoid each year in the UK.
What are the symptoms of Bullous Pemphigoid?
Bullous pemphigoid typically starts with a red, itchy rash that looks a bit like eczema or hives. This tends to last several weeks or months.
Then, groups of large, itchy blisters usually appear on the red patches, just beneath the surface of the skin. They can be up to 5cm in diameter and full of fluid, with the thick skin of the blisters stretched tightly.
The fluid inside is usually clear, but can turn cloudy or blood stained.
Blisters last a few days before healing without leaving a scar, but a cycle develops in which more form.
The rash and blisters are usually seen on the upper arms and thighs, sometimes spreading to body folds and the abdomen (tummy).
However, some people have no symptoms, or just have mild redness and irritation.
Who is affected?
The condition is usually seen in older people aged over 70. Rarely, it can affect children and younger adults.
Both men and women are affected equally.
What causes Bullous Pemphigoid?
Bullous Pemphigoid is an autoimmune condition, which means the immune system attacks the body’s own tissues and organs.
In Bullous Pemphigoid, the person’s immune system produces antibodies against the skin. These antibodies attack the basement membrane, which lies between the skin’s top layer (epidermis) and next layer (dermis) and holds the skin together. The skin layers start to separate and fluid builds up in between.
It’s not understood why autoimmune diseases like Bullous Pemphigoid happen, but it’s thought that something triggers the immune system to attack the body’s own tissues. Certain medicines and sunburn have been known to act as a trigger.
Symptoms usually come on unexpectedly.
It’s not possible to cure the condition with treatment, but it usually goes away on its own within five to six years.
In the meantime, medication is effective in keeping the blisters under control.