Pemphigoid and pemphigus Dr Rob Hicks These are rare autoimmune diseases that make the skin blister.

In this article

What is pemphigoid and pemphigus? Symptoms

Causes and risk factors Treatment and recovery

Pemphigoid and pemphigus are two superficially similar but separate autoimmune diseases that make skin blister. Both are very rare and neither can be cured.

Pemphigoid produces tense, tightly filled blisters that appear mainly on the trunk, arms, and legs and - unlike pemphigus - are rarely found inside the mouth. The blisters can be large, measuring up to 3cm across, and may be itchy and painful.

Pemphigus causes blisters to form that are fragile and burst easily, leaving raw patches of skin that don’t heal without treatment. If firm pressure is exerted on unaffected skin and a shearing strain applied, a blister will appear.

The blisters are frequently itchy and painful and feel as if the skin is burning. People affected by the conditions liken the sensation to having 'a candle burning in the throat'.

Three main types of pemphigus are:

• Pemphigus vulgaris - the most common form ('vulgar' means 'common'), blisters usually appear in the mouth first.
• Pemphigus foliaceus - blisters don't occur in the mouth and those on the skin are more itchy than painful.
• Paraneoplastic pemphigus - the rarest but most serious form, which often occurs when someone has a cancer.

In autoimmune diseases, the body mistakes part of itself as being foreign and triggers an immune reaction - it attacks itself, in other words. In pemphigoid it's the skin cells that are attacked. In pemphigus it's skin cells and often those of the mucosal membranes (the inside of the mouth, for example, as well as the covering of the eye).

When this happens it interferes with the normal structure and function of the cells, causing the burn-like blisters characteristic of these two diseases to appear.

Pemphigoid is the more common but less dangerous of the two and tends to affect older people, usually over the age of 60. There are several different sub-types of pemphigoid.

Pemphigus is less common but untreated can be fatal. It tends to start in middle age. As with pemphigoid, there are several subtypes.

Pemphigus can run in families and, although its precise cause is unknown, a number of possible triggers have been identified:

• Non-steroidal anti-inflammatory drugs such as ibuprofen.
• Drugs derived from penicillamine.
• Herpes simplex virus.
• Exposure to sunlight.
• Long-term stress

Neither pemphigoid nor pemphigus is infectious. Because of the visible nature of these and other skin diseases it's important that those affected get psychological support, as it's easy for anyone with a chronic illness to develop depression.

Both pemphigoid and pemphigus require initial treatment with oral steroids. Other drugs that damp down the response of the immune system so the body stops attacking itself are often used in combination.

Pemphigoid responds readily to this treatment. For more than half of those affected spontaneous remission occurs within a few years with no further recurrence.

Pemphigus may be more difficult to treat, and require a variety of immunosuppressant drugs.

Many of the long term problems and mortality from these two skin conditions result from the treatments, especially the immunosuppressants which can leave a person vulnerable to infection. Close monitoring of the disease and its treatment is needed.

This article was last medically reviewed by Dr Trisha Macnair in June 2009.