Pityriasis is a long—term fungal disease with damage to the epidermis, which is manifested by the appearance of pigmented spots of various shades on the skin: yellow, pink, brown, brown and characteristic bran-like peeling. There are no signs of inflammation. Pityriasis is diagnosed using a Balzer iodine test, luminescent examination and microscopy of exfoliating scales. Treatment is carried out with antifungal ointments and solutions. Pityriasis of the common form requires general antimycotic therapy.
Pityriasis has received this name in connection with its typical peeling. The second name — multicolored lichen — arose due to the diverse coloring of the spots that appear with the disease. The popular name “solar fungus” also has to do with pityriasis. It is due to the fact that under the influence of sunlight, the affected areas of the skin become brighter and more noticeable. The most common cases of pityriasis are men and women of young age, most rarely children under 7 years old.
Pityriasis bran belongs to the group of keratomycosis — fungal skin diseases affecting only the stratum corneum of the epidermis and the hair cuticle. Its pathogens are the fungi Malassezia furfur, Pityrpsporum orbiculare and Pityrosporum ovale, and these species differ in the ability to transform one into another. Usually, pityriasis is characterized by low contagiousness, that is, infection occurs only in some cases with close and prolonged contact with the patient. At the same time, the probability of getting sick with pityriasis is largely due to predisposing factors.
Factors that form a favorable background for the development of pityriasis in the body are: weakening of the immune system, excessive sweating, endocrine disorders (diabetes mellitus, Itsenko-Cushing syndrome, obesity), changes in the chemical composition of sweat, vegetative-vascular dystonia, violation of the barrier function of the skin with frequent use of antibacterial gels and soaps, stress effects on the skin (excessive sunburn, tanning, etc.). The authors of some studies conducted in dermatology indicate that in some cases, pityriasis is associated with lymphogranulomatosis and pulmonary tuberculosis.
Pityriasis is caused by the multiplication of pathogens in the surface layers of the skin, which leads to disruption of the functioning of melanocytes — cells that produce the pigment melanin, which gives the skin a particular color. As a result, the affected area of the skin acquires a color different from the rest of the skin. The process begins at the mouth of the hair follicle, then the spot gradually increases in size.
With pityriasis , the formation of multiple rounded spots up to 1 cm in size is typical . As the spots grow, they merge with each other, forming significant areas that reach the size of more than the palm of an adult. Such spots do not protrude above the surface of the skin and have no signs of inflammation (swelling, redness, soreness). Their color can be yellow, coffee, pinkish-brown, dark brown. The edges of the spots of the pityriasis are clearly delimited, uneven, scalloped. The peeling of spots caused by the loosening of the stratum corneum of the epidermis is characteristic, which is easily detected when the skin is scraped.
Most often, pityriasis appears on the skin of the back and chest. The neck, the sides of the trunk and the abdomen are less often affected. In children and adolescents, spots can be localized on the skin of the extremities, in the axillary areas and on the scalp. There is no symmetry.
A patient with pityriasis, as a rule, does not notice any subjective sensations. In some cases, there is a slight itching in the areas of the skin lesion. The occurrence of soreness, burning or other unpleasant sensations indicates a secondary infection of the skin with bacterial flora.
Pityriasis is characterized by a long-lasting (for several years) the current. In the absence of systematic therapy after treatment, relapses of the disease may occur. Pityriasis is often cured by exposure to sunlight. Areas previously affected by lichen do not tan and remain white against the background of tanned skin (pseudoleucoderm).
Pityriasis is often immediately diagnosed at the consultation of a dermatologist during examination and dermatoscopy of skin areas with altered coloration. To confirm the diagnosis, a Balzer iodine test is carried out, which consists in applying 5% alcohol iodine to the skin. Due to the looseness of the affected areas of the epidermis, the skin in these places absorbs iodine better and is colored more intensively than in healthy areas. With the same success, solutions of aniline dyes can be used to conduct the test: zelenka, iodine, fucarcin. The presence of a symptom of Beignet or the “chip phenomenon” is also determined: peeling of the skin when it is lightly scraped off on the surface of spots of pityriasis.
Luminescent diagnostics carried out in a special darkened room reveals red-yellow or dark brown fluorescence of spots. Microscopic examination of scraping with pityriasis makes it possible to detect elements of the fungus in the scales of the epidermis.
Differentiate pityriasis from pink on the basis of the clinical picture. Pityriasis rosea is characterized by an oblong and diamond-shaped lesion foci, localization of spots along the skin tension lines. Foci of pseudoleucoderma remaining after the pityriasis is resolved differentiate from vitiligo, secondary hypopigmentation, leprosy.
It is also necessary to distinguish pityriasis from syphilitic roseola, and areas of pseudoleucoderm from syphilitic leukoderm. Syphilitic roseola does not peel off, has a pink color, disappears when pressed. Syphilitic leukoderma resembles a lace mesh in its appearance, and not drain spots of reduced pigmentation. To differentiate pityriasis from syphilitic manifestations, the patient may be prescribed the following tests: scraping microscopy for pale treponema, PCR diagnosis of syphilis or RPR test.
Treatment is carried out on an outpatient basis until the complete disappearance of the manifestations of pityriasis. Apply local antifungal agents: 5% salicylic ointment, 3-5% salicylic alcohol, 5-10% sulfur ointment, 3-5% resorcinol alcohol, terbinafine, bifonazole, clotrimazole, cycloperox, terbinafine, naphthyphine, etc. Common pityriasis or its recurrent course is an indication for general antifungal treatment. It is carried out by ingestion of antifungal drugs such as itraconazole, ketoconazole.
Prevention of recurrent pityriasis includes a repeated course of antifungal treatment, regular water procedures and hyperhidrosis therapy. To prevent infection of the patient’s relatives, disinfection of the patient’s clothes and underwear is carried out. People who are in constant contact with the patient are examined using a fluorescent lamp.