Psoriasis is a chronic skin disease of polyetiological nature. Genetic predisposition in the development of the disease is dominant. It is explained by several times increased growth of epidermal cells, a violation of the keratinization process and pathological T-cell immunity. Both men and women suffer from psoriasis. The disease has no age restrictions.
There are two main types of psoriasis. The first type is associated with a hereditary predisposition. It usually develops at a young age. The process is generalized . The second type is not associated with heredity, is localized in certain parts of the body, has a more favorable course. The disease begins after 50 years.
What do we see?
The pathological process is represented by a papulo- squamous rash. The primary element is a nodule (papule), the depth of occurrence is the border of the epidermis and dermis. Papules are located on unchanged skin and tend to merge. Psoriasis papules are covered with silvery white scales ( squam ). Over time, they disappear without a trace. The color of the rash is from pink to salmon. Shape – round, oval, annular, linear. A favorite place for rashes is the scalp, the extensor surfaces of the upper and lower extremities (“duty plaques”), the lumbosacral region, and the genitals.
In its course, the elements of the rash go through three stages:
1 – progressive
2 – stationary
3 – regressive
Signs of progressive psoriasis :
- combination of old and new elements of the rash
- the papule in its environment has a hyperemic corolla ( Pilnov’s symptom )
- with trauma (scratching, burns, etc.), new rashes appear
The stages of development of psoriasis are characterized by the mandatory detection of the so-called Tsumbush psoriatic triad :
1. Stearin spot. When papular rashes are scraped, peeling increases, which gives the papule the appearance of a “stearin spot”.
2. Terminal film. With further scraping, the scales fall off. A wet, translucent, shiny surface remains in their place.
3. The phenomenon of “pinpoint bleeding” (the phenomenon of Auspitz or “blood dew” of Polotebnov ). After scraping the terminal film, punctate bleeding occurs, which are caused by trauma to the papillary layer of the dermis.
Depending on the shape, localization sites, and the degree of the disease, the signs of psoriasis may vary.
In case of damage to the hair and scalp, patients do not go to the doctor for a long time, since psoriatic rashes are hidden under the hair. The rash spreads to the parotid and frontal regions and forms a ” psoriatic crown”.
In children and the elderly, psoriasis is localized in the skin folds – the intertriginous form. In this case, there is no peeling, the color of the papules is bright red, the surface is moist and macerated . In appearance, it resembles a fungal infection of the skin.
In 25% of all cases of damage, signs of psoriasis are found on the nail plates. There is an increase in the nail plate due to the growth of horny masses, its surface is deformed and resembles a “thimble”. A yellow-white spot resembling spilled oil is visible under the nail. The shape of the nail resembles a “bird’s claw”; there may be small- spot subungual hemorrhages ( Leventhal’s symptom ).
In severe advanced cases, psoriasis becomes systemic. Due to itching and scratching of the papules, a secondary infection joins, serous-purulent inflammation occurs, and abscesses (pustules) appear . Papules merge and form “purulent lakes”. This type of psoriasis is treated in an intensive care unit.
Currently, there is no convincing evidence that underlies the pathological process. A large share is occupied by genetic and viral theories, impaired immune response. Therefore, the treatment of patients with psoriasis is rather “palliative”. Despite the brightness of the clinical picture, psoriasis can be confused with other skin pathologies. Therefore, if such a rash is found, it is imperative to consult a dermatologist.