Bullous pemphigoid is a rare, blistering skin disease which can occur anywhere on the skin, but is more commonly found on the folds of the skin, particularly the groin area and the armpits. The disease is more prevalent in the elderly, but an increasing number of people are being diagnosed when in their early fifties. The average age of onset for the disease is between 65 and 75. The condition affects males and females in equal proportion and is rarely life-threatening. In approximately 30% of people the condition burns itself out after a number of years, although a recurrence can occur in later life.
Bullous pemphigoid is an autoimmune disease, where an immune response is triggered to the body's own skin cells. Separation occurs between the epithelial and dermal layers of the skin. The reason for this immune response remains the subject of research. The condition is not contagious and may not be passed on by skin contact.
During a flare-up a non-specific rash first develops on the folds of the limbs. The skin becomes inflamed (erythematous) and very itchy (pruritic). The patient reports feeling very tired and agitated. The disease is at times very debilitating and distressing, with simple tasks becoming a real effort to perform. The stress of the disease can exacerbate the condition. These changes can resemble other skin diseases, such as urticaria, erythema multiforme and dermatitis herpetiformis. Consequently GPs often do not recognise these signs as the early symptoms of bullous pemphigoid. Following this (prodromal) phase, fluid-filled blisters develop. A diagnosis of the condition is confirmed by examination of a blister by skin biopsy. The prodromal phase can last from a single week to several months. Although the condition sometimes remains localised, it is more common for dense bullae to progressively cover both inflamed and normal skin over the majority of the body area. The skin feels hot, itchy and very tender. The lesions, which can be several centimetres in diameter, are particularly concentrated in body folds. Lesions may also develop in the mouth and other mucosal membranes.
When a widespread blistering flare-up occurs, the patient is usually admitted to hospital. As yet there is no cure for bullous pemphigoid, but the condition can be controlled using potent medications. Depending on the severity of the blistering and the patient's general health, it can be treated very successfully using steroids and/or immunosuppressants. A large initial dosage of steroids is administered during a flare-up, in order to bring the blistering under control. These treatments can have harmful side effects, and over the subsequent weeks and months the dosage is gradually reduced until the lowest efficacious dose is attained which will control the condition. A low dosage of the drug treatment is administered for several months or years in order to maintain the condition. It is important to be aware of the risk of infection to the skin, especially when blisters are broken. An antibacterial ointment is routinely applied to the skin for this purpose. In between flares, although the majority of people experience no outward evidence of the disease, it is advisable to keep the skin well hydrated using emollients (creams, lotions and bath oils). Some people find bathing with a non-scented oil very soothing, whilst others have reported an intolerance to any bathing. Some people report adverse reactions to strong sunlight. Although exposure to ultraviolet (UV) light has not been proven to precipitate or to exacerbate the condition, exposing the skin to strong sunlight is inadvisable as the use of steroid creams will have thinned the skin, thereby increasing the risk of skin damage due to sun exposure.