Autoimmune blistering dermatoses

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As pemphigoid a group of is referred to skin diseases in which the body antibodies forms against structures in the skin so that the skin dissolves and form bubbles. These antibodies are directed against components of the epidermis , the so-called desmosomes , or against components of the basement membrane that separates the epidermis and dermis .

Classification

Classification according to ICD-10
L10-L14 Bullous dermatoses
L10 Pemphigus diseases
L11 Other acantholytic dermatoses
L12 Pemphigoid diseases
L13 Other bullous dermatoses
L14 * Bullous dermatoses in diseases classified elsewhere
ICD-10 online (WHO version 2019)

A distinction is made between the following subgroups:

Pemphigus diseases

The antibodies are directed against the desmosomes of the epidermis , special protein molecules that connect the individual keratinocytes (horn cells) with one another. A distinction is also made here between pemphigus vulgaris , in which deeper epidermal layers are affected, so that larger, flaccid blisters develop that contain some liquid, pemphigus foliaceus , in which the superficial epidermal layers are affected, so that the skin peels off like puff pastry and no real blisters arise, as well as other, very rare forms of pemphigus. Pemphigus diseases are very rare in Central Europe and mainly affect patients around the sixth decade of life.

Pemphigoid Diseases

This leads to a loss of contact in the area of ​​the basement membrane. The antibodies are directed against the hemidesmosomes, protein molecules that connect the lowest keratinocyte layer with the basement membrane. Here, too, blisters form, but since the blister cover is formed by the entire epidermis, the blisters in pemphigoid diseases are tight and full. The most important pemphigoid disease is bullous pemphigoid , which is much more common than is often assumed, as many skin symptoms appear even before the blister forms, which are often treated as eczema or psoriasis . There are other forms of pemphigoid, but they are less common. Linear IgA dermatosis and epidermolysis bullosa acquisita also fall into this group. All the diseases mentioned so far - with the exception of the M. herpetiformis Duhring - have in common that IgG antibodies are primarily formed.

Duhring's disease / dermatitis herpetiformis Duhring

The disease Duhring occupies a special position, as the blistering something takes place deeper here. The IgA-type antibodies occurring in this clinical picture are directed against epidermal transglutaminase. Here solid vesicles, urticas and papules (skin nodules) occur particularly on the extensor sides (elbows). The unbearable itching is typical. Flare-ups of the disease are provoked by gluten ( gliadins ) and iodine (sea fish).

Duhring's disease is the cutaneous manifestation of celiac disease (sprue, gluten intolerance). That said, not all sprue will occur with Duhring's disease, but everyone with Duhring's disease will have sprue. However, this need not necessarily be recognizable clinically. A lifelong gluten-free diet is nevertheless a cornerstone of therapy for this disease.

Epidermolysis bullosa acquisita

Here antibodies are directed against collagen 7, a long-chain protein that connects the basement membrane with the underlying connective tissue of the dermis . The disease is very rare. The blisters are plump as in bullous pemphigoid , but blisters seldom develop, but often other symptoms such as vulnerable skin and disorders on the nails.

Diagnosis

In autoimmune blistering dermatoses, the binding of antibodies in the skin is demonstrated. A small sample of unaffected skin is obtained and processed with a special fluorescent dye that binds to the antibodies. Then you look at the skin incision with a fluorescence microscope to see the distribution pattern of the antibodies. So found z. B. in pemphigus diseases a reticulate deposit in the epidermis, while in pemphigoid diseases the antibodies are to be found in a line on the basement membrane. This detection of the antibodies directly in the tissue is also known as direct immunofluorescence . If you want to detect the antibodies in the blood , you can mark them in the serum and then apply them to specially prepared tissue sections of animal and human origin. Evidence of autoimmune blistering dermatosis is not always successful. The advantage is, on the one hand, that a serum sample is much easier to obtain than a skin sample, is also easier to send and, on specially prepared skin, it is also possible to differentiate between pemphigoid and epidermolysis bullosa. This is also referred to as indirect immunofluorescence . The disease activity can also be tracked more precisely in some cases using an ELISA .

therapy

As with many autoimmune diseases , the therapy is also carried out with drugs that have to weaken the immune system. In addition to cortisone preparations , agents such as azathioprine , dapsone or mycophenolate mofetil are also used. In severe cases, the antibodies can also be removed from the blood by means of a type of blood wash ( immunoadsorption ). It may also be necessary to give other medication to avoid the formation of new antibodies.

literature

Web links

Individual evidence

  1. ↑ W. Dieterich u. a .: Antibodies to Tissue Transglutaminase as Serologic Markers in Patients with Dermatitis Herpetiformis. In: Journal of Investigative Dermatology . (1999) 113, pp. 133-136.