Bullous pemphigoid

Also called Pemphigoid, Blistering skin disease

Large tense blisters in older people, usually starting as an intense itch weeks earlier. Frequently mistaken for eczema or scabies.

What it is

An autoimmune blistering disease in which antibodies attack the layer holding the outer skin to the layer beneath, causing large, tense, fluid-filled blisters.

It is the commonest autoimmune blistering condition, and it is overwhelmingly a condition of older people, most often over 75.

The part that gets missed is the beginning. For weeks or months before any blister appears there is often severe itching with non-specific red patches or hives, which gets treated as eczema, scabies or a drug reaction. Persistent unexplained intense itch in an older person, not responding to the usual treatments, should raise the question, and a blood test and skin biopsy can confirm it.

It is associated with neurological conditions, notably dementia, Parkinson's disease and stroke, which is one reason it is common in care settings.

Certain medicines can trigger it, particularly the gliptin class of diabetes drugs, and stopping the trigger can improve it considerably.

It is treatable, usually with strong topical steroid, which is as effective as tablets with fewer risks, and sometimes with oral treatment. It often goes into remission after a year or two.

Signs you might notice

Intense itching, often for weeks or months before anything else.

Red or darker patches, or raised hive-like areas.

Large, tense, dome-shaped blisters, often on the inner thighs, forearms, armpits, groin and abdomen. Unlike many blisters these are firm and do not burst easily.

Blisters that leave raw areas when they do burst.

Mouth involvement in a minority.

It is not usually painful in the way an infection is, and the person is otherwise well.

Same-day: widespread blistering, signs of infection with increasing pain, heat and pus, fever, or a person becoming unwell. Large areas of broken skin lose fluid and become infected easily.

How it can affect day-to-day life

Wound care is the daily work: large raw areas need dressings, and skin over the whole body needs handling gently. District nursing input is usually essential.

The itch alone is exhausting and disturbs sleep, and it is under-treated. Sedating antihistamines at night, cool environments and emollients all help.

Applying potent topical steroid over most of the body is a substantial task and is where treatment quietly fails in a care setting. It has to be somebody's named job, with enough time and enough ointment.

Frail older people with widespread blistering are at real risk from fluid loss, infection and reduced mobility, and mortality in this group is not trivial.

Because it looks alarming, families and staff often assume it is contagious. It is not.

Supporting someone well

For persistent unexplained itch in an older person, ask whether this could be pemphigoid and ask for a dermatology opinion and a biopsy.

Do not treat repeatedly for scabies without evidence; and do treat scabies properly if it is that.

Ask for a review of medicines, particularly gliptin diabetes drugs.

Apply the topical steroid properly, in the amounts prescribed, over the areas prescribed, and make it a named task with enough time allocated.

Do not deliberately burst blisters; leave the roof on where possible, as it protects the skin underneath.

Dress broken areas with non-adherent dressings, and ask for district nurse or tissue viability input.

Treat the itch at night so the person can sleep.

Watch for infection, fluid loss and reduced mobility, and weigh regularly.

Where to get help

A GP practice, asking for dermatology referral; urgent where blistering is widespread.

District nurses or the tissue viability service for wound care.

Same-day for infection or a person becoming unwell.

British Association of Dermatologists publish a patient leaflet on bullous pemphigoid.