How to distinguish psoriasis from dermatitis: clinical presentation, causes and diagnostic methods

Dermatoses of various etiologies occupy one of the leading positions among all diseases. They can be caused by a variety of reasons, manifest at any age, there are frequent cases of the development of pathology in a newborn child. However, how to distinguish psoriasis from dermatitis is very important for a doctor, since the treatment regimen of the disease depends on the specific diagnosis. and further prognosis for the patient, because some skin pathologies are categorized as incurable and can give systemic complications.

Development mechanism

The question of how to distinguish psoriasis from dermatitis can be answered from the point of view of the pathophysiological mechanisms of the development of these diseases. In the first case, genetically predetermined violations of the process of cell division of the upper layer of the skin play a key role in the occurrence of symptoms of pathology. Everyone knows the ability of the epidermis to quickly regenerate, however, in psoriasis, the activity of keratinocytes is significantly higher than normal. This is the reason for the external manifestations of pathology.

Immunocompetent cells are involved in the development of allergic dermatitis, and primarily atopic. Upon contact with a specific stimulus, the lymphocytic system and immunoglobulins are activated. It is these compounds that cause a chain of reactions, ultimately resulting in an enhanced synthesis of various biologically active compounds that stimulate the inflammatory process.

If we are talking about seborrhea, then it is quite difficult to distinguish psoriasis from dermatitis of this type, because the main clinical signs of diseases are in many ways similar. But again, the reasons are dramatically different. The pathogenesis of seborrheic dermatosis is based on disruption of the sebaceous glands located in the deep layers of the epidermis.

As a rule, such disorders are provoked by the microbial flora in combination with immune disorders. But the same factors contribute to the development of almost all forms of dermatitis. First of all, it is a hereditary predisposition, endocrine pathologies, obesity, vitamin deficiency caused by either digestive disorders or dietary habits, lifestyle, harmful habits.

Clinical picture

The next stage in the difference between psoriasis and dermatitis is the clinical picture of the disease. First of all, pay attention to the localization of the rash. So, seborrhea is characterized by the appearance of symptoms in the area of ​​increased concentration of sweat glands. These are the scalp, armpits, folds around the nose.

Atopic dermatitis "loves" sensitive areas of the skin, this is the abdomen, the inner surface of the limbs, buttocks, face. For this type of dermatitis, it is very effective Dupilumab. Symmetrical eruptions are characteristic of psoriasis. They are mainly localized in the area of ​​the elbows, knees, shins. Sometimes the pathology covers the scalp with spread to the neck. Unlike other dermatitis, the nail plate, soles, palms are affected. A rash with contact allergic dermatosis occurs directly at the site of contact with an irritant.

The age at which the disease debuted is also of great importance. Symptoms of allergic dermatosis usually appear in young children, they often coincide with the introduction of the first complementary food, that is, 7-9 months. Sometimes this can happen earlier if you are hypersensitive to cow's milk proteins or if a nursing mother is in violation of the diet. Psoriasis symptoms tend to occur in young people in 20-25 years old.

Although there are known cases of the disease in infants, as well as in preschool and adolescence. This happens especially often if this pathology was diagnosed in both parents. As for the clinical picture, you can distinguish psoriasis from dermatitis as follows.

In allergic dermatosis, the appearance of redness in the overwhelming majority of cases is accompanied by peeling of the skin and severe itching, sometimes the child "combs" them until deep wounds form.

In addition, a clear relationship is monitored between the effect of the allergen on the body and the development of clinical symptoms. Psoriasis starts with small papules that connect to each other. Gradually, they become covered with silvery scales, which are abundantly crumbled when scraped. Under them, the skin is smooth, shiny, and when damaged, the blood appears in the form of small drops. Because of these manifestations, the disease was previously called scaly lichen.

In patients with seborrhea, scales also form on the areas of the affected skin, but usually they are of a cloudy yellowish tint, it is difficult to scrape off. Profuse dandruff is noticeable in the hair, the skin is very shiny due to excessive accumulation of sebaceous secretions. If you run your finger over the face of such a patient, a distinct greasy mark is left.

Analyzes

As a rule, a visit to any doctor begins with the delivery of standard laboratory tests: blood, urine and feces. It would seem that the latter has nothing to do with dermatoses, but this analysis can reveal signs of helminthic invasion, which is often accompanied by external manifestations on the skin, and according to the results of the coprogram, it can be assumed dysbiosis. When examining blood, attention is paid to the level of ESR (in psoriasis, it is increased due to an active inflammatory process) and the concentration of eosinophils.

An increase in their number almost always indicates an allergic reaction. In addition, an immunogram is mandatory. The main indicator of interest to doctors is the level of class E immunoglobulin.

With psoriasis, it does not exceed the norm, with allergic dermatitis, its value is increased. Scraping the skin will not help, however, it will differentiate them from infectious or fungal lesions of the epidermis. In some cases, in the presence of open wounds, the course of dermatoses can be complicated due to the ingress of pathogenic microflora.

However, scraping will help to adjust the treatment in time. Allergy tests, which are carried out in the process of diagnosing allergic dermatitis, are not done with psoriasis. This is due to the fact that the introduction of an additional allergen can provoke an exacerbation of the disease. Relatively recently, research methods have appeared in the arsenal of doctors that make it possible to assess the level of antigens and blood factors that are involved in the development of psoriasis. In other forms of dermatitis, their level remains normal. A general examination of the patient is also mandatory.

An ultrasound of the abdominal cavity is done, if necessary, the mucous membrane of the digestive tract is examined. A biochemical blood test is required to assess liver function. This will not help much to distinguish psoriasis from dermatitis, but it will help to identify the possible cause and complications of the disease.