Bullous pemphigoid is a fatal skin disease that causes fluid- filled, large blisters (known as bullae) on areas of the skin which often flex such as upper thighs, lower abdomen, or armpits. It is a rare disease and occurs mostly in people above the age of 60 years. It is an inflammatory, chronic, blistering, sub epidermal disease. Bullous pemphigoid can persist for years and months if left untreated with periods of exacerbations and remissions. For patients who are debilitated, it is more dangerous.
Bullous pemphigoid is categorized under the type II hypersensitivity reaction. The blisters developed in this disease are itchy and are filled with blood- stained, cloudy, or clear fluid. They may appear on inflamed or normal skin. A vague itchy, red rash may mark the beginning for several months or weeks before the actual blister appears. The rash may be mistaken as urticaria or dermatitis problems. They are often in circular shapes and have a dry surface. They might get cured in early stages without or with treatment. Bullous pemphigoid may be confined to a small area or may even spread on the proximal limbs and trunk. In worse cases, the blisters may be widespread and occurs all over the skin and even inside the mouth. After the blisters are healed, they usually leave brown colored marks caused due to post inflammatory pigmentation. Other post effects may be small cysts called milia; these cysts might take a few months to disappear.
The primary cause of bullous pemphigoid is an immune system attack on the outer layer skin tissues. The actual reason of this attack is still not known but it may be due to some type of medications. The treatment of this disease is done by suppressing the immune system using corticosteroids and other drugs. For older people this disease can prove to be quite fatal.
Bullous pemphigoid has many distinct clinical features such as:
- The most common bullous pemphigoid are the generalized bullous form. Fluid filled bullae arise on the folded areas of the skin
- The vesicular form is less usual than the generalized bullous form, it occurs as a group of tensed, small blisters on the erythematous or urticarial base
- The vegetative form is quite uncommon, in the areas such as neck, axillae, groin, and other intertriginous areas of the skin
- The generalized erythroderma form is another infrequent presentation which may resemble atopic dermatitis, psoriasis, or other exfoliative erythroderma caused skin diseases
- The urticarial form is initially marked by urticarial lesions that gradually convert into bullous eruptions. In some patients lesions may be the only symptoms of bullous pemphigoid
- The nodular form is another unusual form, called pemphigoid nodularis. The symptoms may resemble prurigo nodularis
- The acral form is associated with vaccination in childhood bullous pemphigoid. The face, soles, and palms are adversely affected by the bullous lesions
- The infant form usually has generalized blisters that are prey to bullous pemphigoid. They mostly affect the soles, palms, face, and rarely the genital areas.
The general features of bullous pemphigoid blisters are that they do not rupture easily on touch and the skin around them may be red or normal. Apart from the folded skin areas they may occur in mouth and the mucous membrane of the eyes.
As stated above the actual causes of bullous pemphigoid are still not well known and the cause of blisters is the abnormal reaction of the immune system. In this reaction, the immune system changes its default behavior of producing antibodies against viruses, bacteria, and other harmful foreign bodies and develops antibodies against some tissues of the body in particular. These antibodies cause inflammatory action on the skin’s basement layer. This is a thin fiber layer which connects the epidermis (outer skin layer) and the dermis (the next layer of the skin). Hence the itching and blisters of bullous pemphigoid are developed.
Other contributing factors can be some of the medical treatments like the drugs prescription of etanercept (Enbrel), penicillin, furosemide (Lasix), and sulfasalazine (Azulfidine). Treatments involving light and radiation like ultraviolet light therapy and other cancer therapies.
Unless severe condition, bullous pemphigoid can be treated without being admitted to hospital. The most common treatment involves steroid tablets, usually prednisone. The treatment usually continues for weeks until the blisters stops appearing. The dose of the drugs is adjusted and reduced gradually with time. There are many side effects of systemic steroids so other medications are included so as to reduce the quantity of prednisone to the minimum. The other medications included are:
- Tetracycline antibiotics
- Typical steroids such as clobetasol
The outlook for bullous pemphigoid is good and it is cured in about 1-5 years of treatment. The treatment reduces the blisters to a remarkable extent and the treatment may not be needed after 1-5 years.
Bullous Pemphigoid Pictures