Pemphigoid: A rare autoimmune disorder

Pemphigoid is a rare autoimmune disorder that can develop at any age, including in kids, but that most often affects the elderly. Pemphigoid is caused by a malfunction of the immune system and results in skin rashes and blistering on the legs, arms, and abdomen.

Pemphigoid can also cause blistering on the mucous membranes. Mucous membranes produce mucous that helps protect the inside of your body. Pemphigoid can be found on the mucous membranes in your eyes, nose, mouth, and genitals.

It can also occur during pregnancy in some women. There is no cure for pemphigoid, but there are various treatment options.

Symptoms of Bullous Pemphigoid

The primary feature of bullous pemphigoid is the appearance of large blisters that don’t easily rupture when touched. The fluid inside the blisters is usually clear but may contain some blood. The skin around the blisters may appear normal, reddish or darker than usual. Some people with bullous pemphigoid develop an eczema or hive-like rash rather than blisters.

In most cases, the blisters appear on the lower abdomen, groin, upper thighs and arms. Blisters are often located along creases or folds in the skin, such as the skin on the inner side of a joint.

The affected areas of skin can be very itchy. You might also develop blisters or sores in your mouth. If the mucous membranes of your eyes and mouth are primarily where your blisters are concentrated, this type of condition is called mucous membrane pemphigoid. If you develop blisters on your eyes, you’re more likely to have scarring. This condition requires prompt diagnosis and treatment.

What causes Bullous Pemphigoid (BP)?

BP is an autoimmune disease. The immune system normally makes antibodies to attack bacteria, viruses, and other germs. In people with autoimmune diseases, the immune system also makes antibodies against a part or parts 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 autoimmune 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, but they are not thought to cause it.

They may be trigger factors. They include:

• Diseases such as ulcerative colitis and multiple sclerosis.
• Medications such as furosemide, non-steroidal anti-inflammatory drugs (NSAIDs), captopril, penicillamine and some antibiotic medicines.
• Other factors such as ultraviolet radiation and radiotherapy.

Who gets bullous pemphigoid?

Bullous pemphigoid often presents in people over 80 years of age, and mostly affects people over 50. It can occur in younger adults, but bullous pemphigoid in infants and children is rare.

• Bullous pemphigoid occurs equally in males and females.
• There are HLA associations indicating genetic predisposition to the disease.
• It is more prevalent in elderly patients with neurological disease, particularly stroke, dementia and Parkinson disease.
• The risk of developing bullous pemphigoid is greater in people with the skin disease, psoriasis, and it can be precipitated by treatment of psoriasis with phototherapy.
• There may be an association with internal malignancy in some patients.
• A drug, an injury, or skin infection can trigger the onset of disease.

Types of Pemphigoid

Bullous Pemphigoid

In cases of bullous pemphigoid (the most common of the three types), the skin blistering happens most commonly on the arms and legs where movement occurs. This includes the areas around the joints and on the lower abdomen.

Cicatricial Pemphigoid

Cicatricial pemphigoid refers to blisters that form on the mucous membranes. This includes the mouth, eyes, nose, throat, and genitals. The rash and blistering may begin in one of these areas and spread to the others if left untreated.

Pemphigoid Gestationis

When blistering occurs during or shortly after pregnancy, it is called pemphigoid gestationis. It is also called herpes gestationis, although it is not related to the herpes virus. The blistering typically develops during the second or third trimester, but may occur at any time during pregnancy or up to six weeks after delivery. Blisters tend to form on the arms, legs, and abdomen.

Risk factors

Bullous pemphigoid most commonly occurs in people older than age 60, and the risk increases with age.

Complications

If ruptured blisters become infected, this can lead to sepsis  a potentially life-threatening blood infection that affects your entire body. Sepsis is more likely to occur in older adults who are in generally poor health.

Rare forms of bullous pemphigoid involving the mucous membranes of the mouth or eye can lead to scarring.

What is the treatment of bullous pemphigoid (BP)?

Treatment involves suppressing the immune process, so that itching and blistering are reduced. The aim is to find the right balance of treatment. You need to feel comfortable and 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 having more side-effects.

Treatments used for BP are:

Steroids

Steroid creams, also called topical steroids, are a safe and effective treatment for BP. High-strength steroid creams (eg clobetasol) will normally be needed. Research suggests that steroid creams are a good option for most types of BP, even the more severe forms. This research also suggests that certain steroid creams are more effective than steroid tablets, have fewer side-effects and give better results overall.

Steroid tablets such as prednisolone are also used as treatment for BP. They are used when the rash is widespread, or there are practical problems applying the cream. 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.

Other treatments

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

• Skin treatments such as dressings and wound care, which will be needed if you have areas of raw skin.
• Medicines called dapsone and sulfonamides, which are sometimes used if steroids have not been effective. They tend to cause more side-effects and so are not used as often as steroids.
• A newer medication called rituximab, which has been useful in difficult-to-treat cases.