Dühring's dermatitis herpetiformis

Dermatitis herpetiformis Duhring (synonyms: Duhring's disease, herpes pemphigoid, etc.) belongs to the group of herpetiform dermatoses.

This group of diseases includes dermatoses that are different in etiology and pathogenesis, but similar in clinical and morphological manifestations of rashes, which are characterized by a herpetiform grouping of rashes. In addition to Duhring's herpetiform dermatitis, this group also includes herpes of pregnancy and subcorneal pustulosis.

The name of this disease was given by Philadelphia dermatologist Duhring in 1884. At present, the disease is not rare and occurs in people of any age group. Men get sick more often than women.

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Causes and pathogenesis of dermatitis herpetiformis Duhring

The causes and pathogenesis of the disease remain unclear to this day. Duhring's dermatitis herpetiformis is considered to be a polysystemic disease of autoimmune origin. The polysystemic nature of the disease is confirmed by the fact that the signs of enteropathy are caused by increased sensitivity to gluten, in particular to gluten found in cereal proteins. In this regard, the prescription of a gluten-free diet for therapeutic purposes leads to both clinical improvement and normalization of the small intestinal mucosa. Detection of IgA antibodies in the papillary layer of the dermis or along the basement membrane of circulating immune complexes in the blood serum indicates the autoimmune nature of the dermatosis. Some dermatologists believe that hereditary predisposition, increased sensitivity to iodine, decreased antioxidant activity, in particular SH-groups, etc. are of great importance in the development of dermatosis. In some cases, Duhring's disease is considered a paraneoplastic process.

Most authors classify Duhring's dermatitis herpetiformis as an autoimmune disease with the presence of IgA antibodies against structural components of the dermal papillae near the basement membrane. V.V. Serov (1982) considers dermatitis herpetiformis to be an immune complex disease caused by various exogenous antigens. Indirectly, the immune nature of dermatitis herpetiformis is confirmed by its combination with other autoimmune processes. The role of gluten enteropathy in the development of the disease is indicated. Depending on the nature of IgA deposition (granular or fibrillar) on the tips of the dermal papillae or linear along the basement membrane, two variants of this dermatosis are distinguished. Granular deposits predominate, occurring in 85-95% of cases. According to S. Jablonska and T. Chorzelsky (1979), the granular type of IgA deposition is characteristic of patients suffering from gluten enteropathy.

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Histopathology of Duhring's dermatitis herpetiformis

A blister is noted under the epidermis, which is formed as a result of separation of the epidermis from the dermis under the influence of edema of the tsh in the upper part of the skin itself. The epidermis above the blister is unchanged. The blister is rounded and contains a significant number of eosinophils. IgA is detected in the dermo-epidermal zone or in the papillary layer of the dermis.

Pathomorphology of Duhring's dermatitis herpetiformis

A typical picture of herpetiform dermatitis is observed in the erythematous elements of the rash at the early stages of the process, which is expressed in the accumulation of neutrophilic granulocytes with an admixture of eosinophilic ones in the area of the apex of the dermal papillae, with an increase in the number of which microabscesses are formed. In the latter, in addition to neutrophilic and eosinophilic granulocytes, fibrin accumulates; the tissue of the papillae in these areas undergoes necrosis. Interpapillary outgrowths of the epidermis remain attached to the dermis, as a result of which the blisters are multi-chambered. After a few days, the connection of the epidermal outgrowths with the dermis is disrupted, the blisters increase, become single-chambered and clinically pronounced. Very often, papillary microabscesses characteristic of this disease can be seen histologically along the periphery of a single-chambered blister. Sometimes in long-existing foci, due to the regeneration of the epidermis, gradually covering the bottom of the blisters, they rise higher, becoming intraepidermal and can be located in the spinous and horny layers. In the subepidermal parts of the dermis, a moderate inflammatory infiltrate of neutrophilic and eosinophilic granulocytes is visible, among them there are many destroyed nuclei, forming the so-called nuclear dust. In the lower parts of the dermis - perivascular infiltrates consisting of mononuclear elements with an admixture of neutrophilic granulocytes. The above-mentioned signs are not always detected in biopsy specimens. Thus, according to B. Connor et al. (1972), papillary abscesses occur in 50%, subepidermal blisters - in 61%, "nuclear dust" in the upper parts of the dermis - in 77% of cases.

Histogenesis

The mechanism of blister formation is unclear. Direct immunofluorescence test in this disease reveals IgA deposits in the dermoepidermal junction of unaffected skin and in erythematous foci at the beginning of the process, mainly at the apex of the dermal papillae and also inside them. In some cases, IgG deposition is observed, less often - IgM. Antithyroid antibodies, antibodies against gastric parietal cells and IgA nephropathy have also been detected. In recent years, the significance of antibodies against gliadin, reticulin and smooth muscle endomysium has been studied. Specificity of IgA to gliadin has been shown, however, their frequency in herpetiform dermatitis is low, therefore, they have no diagnostic value. Sensitivity and specificity of antireticulin antibodies and antibodies against endomysium have been established. In most patients, the production of antibodies (IgA) is provoked by the gluten antigen, which is contained in the gluten of flour and grain products, which comes with food; it also causes enteropathy characteristic of the disease. There is an association of the disease with some antigens of the HLA system: HLA-B8, DR3, etc. The HLA-B8/D3 haplotype is found in patients with Duhring's dermatitis herpetiformis several times more often than in the control.

In 25-35% of patients with Duhring's dermatitis herpetiformis, circulating immune complexes are detected, which gives grounds to classify this disease as an immune complex disease.

Symptoms of Dermatitis Herpetiformis Duhring

Mostly middle-aged and elderly people get sick, and less often children.

Clinical manifestations of the disease are polymorphic, there are erythemato-edematous (urticarial-like), papular, papulovesicular, vesicular and, less frequently (mainly in the elderly), bullous rashes accompanied by burning and itching. The rash is often located symmetrically on the skin of the extremities, mainly in the area of large joints, shoulders, and buttocks. A tendency to grouping is characteristic, the development of hyperpigmentation at the sites of regressed rash is typical. Atypical (eczematoid, trichophytoid, strophuloid, etc.), mixed (having signs of Duhring's herpetiform dermatitis and pemphigoid) clinical variants are described, petechial-ecchymotic purpura localized on the skin of the palms is also possible. In atypical cases, as well as when the process develops in elderly people, paraneoplasia must be excluded. Nikolsky's symptom is negative, sensitivity to iodine preparations is increased. Many eosinophils are found in the blood and the contents of the blisters. The course of the disease is long, cyclic, with remissions and paroxysmal exacerbations. The mucous membranes are affected less often than in pemphigus, mainly in IgA-linear bullous dermatitis, which is considered a similar process to the classic Duhring's dermatitis herpetiformis. A feature of cases with a linear arrangement of IgA is the presence of clinical and morphological signs of Duhring's dermatitis herpetiformis and bullous pemphigoid. In children, similar manifestations are designated as a juvenile form of IgA-linear dermatosis, which, according to M. Meurer et al. (1984), is probably identical to the previously described benign bullous dermatosis of children.

Before the rash begins, some patients experience prodromal symptoms (general malaise, fever, tingling of the skin). The disease is characterized by true polymorphism and is represented by erythematous spots, urticarial papules, vesicles, blisters and pustules. Depending on the predominance of elements in the lesions, vesicular, erythematous, bullous and pustular types of the clinical course of Duhring's dermatitis herpetiformis are distinguished. But sometimes the rash is monomorphic.

Dermatosis is characterized by the appearance of rashes on an erythematous background, but sometimes on clinically unchanged skin. The elements of the rash (spots, urticaria-like papules, vesicles, blisters and pustules) differ from similar rashes in other dermatoses. Round erythematous spots are small in size, have a smooth surface, and clear boundaries. Urticaria-like elements and papules have bizarre and scalloped outlines with clear borders of pink-red color. Excoriations, hemorrhagic crusts and scales are visible on the surface of spots, urticaria-like elements and papules. Small blisters (0.2-0.5 cm in diameter) appear on an edematous erythematous base and have a pronounced tendency to herpetiform arrangement (the second characteristic feature), a tense cover and transparent contents, which over time become cloudy and may become purulent. There is a vesicular form of dermatosis. The size of the blisters is from 0.5 to 2 cm or more. The cover of the blisters is dense and thick, so they do not burst so quickly. They usually appear on an erythematous, slightly edematous background, but can develop on outwardly unchanged skin. The contents of the blisters are usually transparent, rarely hemorrhagic, and if infected, purulent. A combination of bullous and vesicular forms of the disease is often noted. When opening, the blisters form erosions with a weeping surface, along the periphery of which scraps of the covers of the blisters and blisters are visible. The blisters usually do not tend to grow peripherally. Crusts form on the surface of the erosion, under which epithelialization occurs quickly, leaving areas of hyperpigmentation. Nikolsky's symptom is negative.

The third characteristic feature of Duhring's dermatitis herpetiformis is the presence of intense itching and burning, especially at the onset of the disease.

The disease occurs in attacks, i.e. it recurs at different intervals. Sometimes, in the most severe cases, the rashes exist permanently for a long time, not disappearing even under the influence of the therapy. The predominant localization of the rash is the extensor surfaces of the extremities, the area of the shoulder blades, buttocks, sacrum, but the process can also affect any part of the body.

Mucous membrane lesions are not typical. In rare cases, vesicular-bullous elements are observed. In this case, superficial erosions of irregular shape are visible, along the circumference of which there are fragments of vesicle covers.

For Duhring's disease, the skin and internal test with potassium iodide (Jaddason test) are of great diagnostic value. Eosinophilia is detected in the blood and cystic fluid. Acantholytic cells are always absent.

Herpetiform dermatitis in pregnant women (herpes gestationis, herpes of pregnancy) usually begins in the 3rd-4th month of pregnancy, but sometimes after childbirth. Small cone-shaped vesicular or pustular elements appear on the skin of the trunk and limbs against the background of erythematous-urticarial spots. Generalized itching and widespread erythematous-vesicular rashes are usually observed, accompanied by more or less pronounced general symptoms. The blisters merge with each other, open, and their contents dry up into crusts. Sometimes blisters with a dense cover can be found. Mucous membranes are rarely affected. Relapse of the disease is noted during the next pregnancy.

In clinical practice, localized herpetiform dermatitis or herpetiform dermatitis of the Cottini type is rarely observed. The skin pathological process is located in the area of the elbows and knees, sometimes in the sacral area.

Diagnosis of Dermatitis Herpetiformis Duhring

The disease should be distinguished from the bullous variety of erythema multiforme exudative, bullous pemphigoid, various forms of acantholytic pemphigus, bullous toxicoderma, the vesicular variety of Darier's centrifugal erythema, etc.

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Treatment of Dermatitis Herpetiformis Duhring

First, it is necessary to follow a diet: exclude gluten-rich foods from the diet. Treatment depends on the severity of the disease. Diamino-diphenylsulfone (dapsone, diucifon) is prescribed orally at 0.05-0.1 g 2 times a day for 5-6 days with a three-day interval. In severe cases, glucocorticosteroids are recommended orally. The dose depends on the patient's condition and the clinical picture of the dermatosis (on average, 40-60 mg/day is prescribed). Aniline dyes and corticosteroid ointments are used externally.