Bullous pemphigoid is a skin disease (dermatosis).

The latter is characterized by the development of large bubbles on erythematous plaques (red plaques on the skin). The appearance of these bubbles leads to lesions and is often the cause of itching. (1)

It is an autoimmune disease, the consequence of a disruption of the immune system in the affected person. This regulation of the immune system consists of the production of specific antibodies against its own body.

This pathology is rare but can turn out to be serious. It requires long-term treatment. (1)

Although it is a rare disease, it is also the most common of autoimmune bullous dermatoses. (2)

Its prevalence is 1 / 40 (number of cases per inhabitant) and mainly affects the elderly (on average around 000 years old, with a slightly increased risk for women).

An infantile form also exists and affects the child during the first year of his life. (3)

Bullous pemphigoid is a dermatosis of autoimmune origin. The subject suffering from this disease therefore produces antibodies against his own organism (autoantibodies). These attack two types of proteins: AgPB230 and AgPB180 located between the first two layers of the skin (between the dermis and the epidermis). By causing a detachment between these two parts of the skin, these auto-antibodies lead to the formation of the bubbles characteristic of the disease. (1)

The atypical symptoms of bullous pemphigoid is the appearance of large bubbles (between 3 and 4 mm) and of a light color. These bubbles mainly occur where the skin is reddish (erythematous), but can also appear on healthy skin.

Epidermal lesions are usually localized in the trunk and limbs. The face is more often spared. (1)

A pruritus of the skin (itching), sometimes early when the bubbles appear, is also significant of this disease.

Several forms of the disease have been demonstrated: (1)

– the generalized form, the symptoms of which are the appearance of large white bubbles and itching. This form is the most common.

– the vesicular form, which is defined by the appearance of very small blisters in the hands with intense itching. This form is however less common.

– the urticarial form: as its name suggests, results in hives patches also causing severe itching.

– the prurigo-like form, the itching of which is more diffuse but intense. This form of the disease can also cause insomnia in the affected subject. In addition, it is not bubbles that are identifiable in the form of prurigo type but crusts.

Some patients may not have any symptoms. Others develop a slight redness, itching, or irritation. Finally, the most common cases develop redness and severe itching.

The blisters can burst and form ulcers or open sores. (4)

Bullous pemphigoid is an autoimmune dermatosis.

This origin of the disease results in the production of antibodies (proteins of the immune system) by the body against its own cells. This production of autoantibodies leads to the destruction of tissues and / or organs as well as inflammatory reactions.

The real explanation for this phenomenon is not yet known. Nevertheless, certain factors would have a direct or indirect link with the development of autoantibodies. These are environmental, hormonal, medicinal or even genetic factors. (1)

These autoantibodies produced by the affected subject are directed against two proteins: BPAG1 (or AgPB230) and BPAG2 (or AgPB180). These proteins have a structural role in the junction between the dermis (lower layer) and the epidermis (upper layer). These macromolecules being attacked by autoantibodies, the skin peels off and causes bubbles to appear. (2)

In addition, no contagion is to be associated with this pathology. (1)

In addition, symptoms generally appear spontaneously and unexpectedly.

Bullous pemphigoid is not, however: (3)

– an infection ;

– an allergy ;

– a condition related to lifestyle or diet.

Bullous pemphigoid is an autoimmune disease, in that sense it is not an inherited disease.

Nevertheless, the presence of certain genes would be a risk of developing the disease in people carrying these genes. Either there is a certain genetic predisposition.

This risk of predisposition is, however, very low. (1)

Since the average age of disease development is around 70, a person’s age may be an additional risk factor for developing bullous pemphigoid.

In addition, we must not overlook the fact that this pathology is also defined through an infantile form. (3)

In addition, a slight predominance of the disease is visible in women. The female sex therefore makes it an associated risk factor. (3)

The differential diagnosis of the disease is mainly visual: appearance of clear bubbles in the skin.

This diagnosis can be confirmed by a skin biopsy (taking a sample from the damaged skin for analysis).

The use of immunofluorescence can be used in the demonstration of antibodies following a blood test. (3)

The treatments prescribed in the context of the presence of bullous pemphigoid aim to limit the development of bubbles and to heal the bubbles already present in the skin. (3)

The most common treatment associated with the disease is systemic corticosteroid therapy.

However, for localized forms of bullous pemphigoid, topical corticosteroid therapy (only acting where the drug is applied), combined with class I dermatocorticoids (drug used in local skin treatment). (2)

A prescription for antibiotics of the tetracycline family (sometimes associated with vitamin B intake) may also be effective by the doctor.

Treatment is often prescribed for the long term and is effective. In addition, a relapse of the disease is sometimes observable after stopping treatment. (4)

After diagnosis of the presence of bullous pemphigoid, consultation of a dermatologist is strongly recommended. (3)