Generalized pustular psoriasis is a rare type of severe psoriasis with exudative-proliferative processes in the dermis, alternating remissions and relapses. It is clinically manifested by erythema, against the background of which a bubble rash erupts, over time turning into small bright pink pustules. Rashes have no preference in localization, merge with each other, regressing, opening, peeling, infiltrating the affected areas of the skin. The main diagnostic criterion is the presence of a psoriatic triad: the phenomenon of stearin stain, terminal film, drip bleeding. Treatment is aimed at relieving inflammation and suppressing proliferation.
L40.1 Generalized pustular psoriasis
Generalized pustular psoriasis (Tsumbush’s disease) is a chronic, recurrent immuno–mediated dermatosis of severe course, posing a danger to human life. Unlike vulgar psoriasis, which accounts for about 3% of all skin diseases, pustular psoriasis is not widespread. It has no gender coloring, can make its debut at any age, but mainly occurs during puberty. Although not endemic, pustular psoriasis gives a high incidence in areas where eating “fatty” foods leads to lipid metabolism disorders (atherogenic nutrition profile).
The first mention of psoriasis under the name of “leprosy”, “psora”, “lichen” is already in the writings of Hippocrates. Varieties of psoriasis were described by A. Celsus, R. Villan, D. Wilson, but F. united them into one whole. Coat of arms in 1841. Pustular psoriasis was first described by the Austrian dermatologist Zumbusch in 1910, giving his name to this dermatosis. In 1917, under the guise of vesicular psoriasis, this type of pathology was described by the German doctor A. Kismaier, in our country in 1965 – Professor L.N. Mashkilleyson. The relevance of generalized pustular psoriasis is associated with the possibility of a fatal outcome.
There is no consensus on the cause of the occurrence and development of the disease. It is known that generalized pustular psoriasis occurs in 60% of cases in patients already suffering from vulgar psoriasis, in 40% it develops “spontaneously”, against the background of complete well-being. If the cause of the disease in the first case is practically clear – it is inadequate therapy of vulgar psoriasis with “overkill” in the dosage and duration of use of cytostatics, corticosteroids, topical drugs, causing a kind of allergic contact dermatitis, then with the “spontaneous” development of pathology, everything is much more complicated. The reason for this onset of the disease is unknown.
The mechanism of development is not fully understood. Currently, two theories are considered to be the main ones in dermatology: immune and metabolic. Modern researchers believe that the most likely immune mechanism for the development of generalized pustular psoriasis with a pronounced genetic accent. The trigger mechanism is exo-endogenous “provocateurs” (hereditary predisposition, stress, alcohol, infection, medicine, skin injury).
The malfunction of the immune system occurs at the cellular-humoral level. In peripheral blood, the ratio of immune complexes, T- and B-lymphocytes is disrupted, which leads to skin sensitization, the development of an antigen-antibody reaction. In this case, the role of the antigen begins to play, including the cells of their own epidermis. In parallel, intracellular regulation is disrupted, causing hyperproliferation of healthy skin. Aggressive changes in the behavior of keratinocytes contribute to the development of inflammation in the dermis, a new activation of T-lymphocytes, forcing them to re-perform the role of mediators of inflammation, proliferation. This creates a vicious circle that determines the chronic course of dermatosis.
The metabolic theory of the pathogenesis of generalized pustular psoriasis is based on dyslipidemia: low HDL (high density lipoproteins), high total cholesterol, triglycerides (TG), oxidized modified lipids, LDL (low density lipoproteins). In this case, the skin cells begin to secrete special proteins – cytokines. Enzymatic processes are intensified in the skin, the cycle of development of epidermocytes is accelerated, the process of hyperkeratosis formation is activated. The exchange theory is supported by the fact that in generalized pustular psoriasis, a metabolic syndrome is expressed, including dyslipidemia as the main component.
There is no consensus on the classification of generalized pustular psoriasis. Some authors interpret this dermatosis as a constructor consisting of 3 components: pustular psoriasis Tsumbush, generalized acrodermatitis Hallopeau, herpetiform impetigo. However, acrodermatitis Hallopeau, which affects only the extremities, and herpertiform impetigo, which occurs in pregnant women, in fact, are independent nosological units. Therefore, in our opinion, it is possible to classify Tsumbush’s disease only from the point of view of the stages of the process. At the same time, the following stages of the disease are distinguished:
- the stage of progression is the development of an inflammatory process accompanied by a rash of primary elements, itching, peeling;
- stationary stage – there are no changes in the clinical picture;
- the regression stage is the final of the skin process with the regression of the primary elements starting from the center, with the outcome in depigmentation.
Generalized pustular psoriasis is characterized by an acute onset: high fever, fever, chills, sudden appearance of bright hyperemia anywhere on the skin. The erythematous spot is hot to the touch, accompanied by a burning sensation of the skin. Almost immediately, against the background of erythema, the primary elements of the inflammatory process appear – small bubbles filled with transparent contents, which quickly become cloudy, transforming into pustules. The elements of the rash begin to merge with each other into foci of psoriatic inflammation, where the pustules open, dry out, form flake-crusts on the surface of the elements, begin to peel off. Foci tend to peripheral growth, as evidenced by a bright inflammatory corolla, devoid of scales, along the perimeter.
This is how the stage of “maturation” proceeds, the progression of the disease. It is followed by relative peace. The foci of inflammation take the form of plaques, no new elements appear, the skin is infiltrated, flakes off profusely. This is a stationary stage. Finally, there comes a stage of regression, when erythema and infiltration noticeably decrease, peeling stops, plaques begin to resolve from the center, a pseudoatrophic belt appears on the periphery. The outcome of regression is depigmentation.
With a generalized form of pustular psoriasis, nails are affected. They thicken, become cloudy yellow, crumble, break. Small indentations appear on the nail plate, the nail becomes like a needle-pierced plate, a thimble. The sub-elbow space is affected by pustules, the size of a pinhead, visually this process resembles an oil stain. Complete deformation (onychogryphosis), “dissolution” of the nail plate (onycholysis) often occurs. The scalp is affected on “general grounds”, the hair does not change, does not fall out.
The severity of generalized pustular psoriasis depends on the severity and speed of the spread of the pathological process, the final outcome of which may be fatal. In this regard, it becomes very important to predict the course of pathology using PASI – a special index calculated in points (72 in total), taking into account the area of the affected skin surface, the degree of hyperemia, infiltration, peeling. Severe forms are estimated at 50 or more points.
The diagnosis is made based on the identification of a specific triad of clinical symptoms that can be obtained on individual plaque elements of a common process: stearin stain when scales are scraped on the surface of the plaque, terminal film under the removed scales with drip bleeding appearing through it. Take into account the symptom of a “thimble” of nail plates, an “oil stain” in the subcutaneous space; the appearance of new elements in places of violation of the integrity of the skin as a result of an abrasion or injury (Kebner’s symptom). Generalized pustular psoriasis is differentiated with seborrhea, lichen planus, pink Zhiber’s lichen, neurodermatitis, parapsoriasis, toxicoderma.
Therapy of Tsumbush’s disease requires time, patience, perseverance. It is necessary to carry out symptomatic, anti-inflammatory treatment, to suppress proliferation, taking into account the severity and prevalence of the process. 50-point forms (and more) are treated inpatient, selecting an individual course of therapy for patients. Retinoids, immunosuppressants (cyclosporine), cytostatics (methotrexate), hepatoprotectors, phosphodiesterase inhibitors (vinpocetine) are used in the treatment. Plasmapheresis, hemosorption, selective phototherapy are shown. It is impossible to stop the process completely, but it is possible to achieve a long-term remission.
Forms with a score of less than 50 points are treated on an outpatient basis. Retinoids, vitamin therapy (D, C, E), antihistamines (clemastine), sedatives, PUVA therapy for psoriasis, hemodesis, UVI are used. Keratolytics, hormonal ointments are applied externally. Climatotherapy is shown: Matsesta, Naftalan, Dead Sea. The prognosis is relatively unfavorable, given the possibility of a fatal outcome.