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Seborrheic dermatitis and dandruff
Last reviewed: 11.04.2020
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[What causes seborrheic dermatitis?
The cause of seborrheic dermatitis is the reproduction in the estuaries of the hair follicles of the lipophilic yeast-like fungus Pityrosporum ovale (Malassezic furfur). This fungus saprophytes on the skin areas abundantly provided with sebaceous glands. The frequency of its release in healthy people ranges from 78 to 97%. However, with certain changes in the protective biological surface system of the skin, P. Ovale receives favorable conditions for reproduction and exhibits the properties of a pathogenic fungus. Endogenous factors predisposing to the development of seborrheic dermatitis include seborrhea, endocrine diseases (diabetes mellitus, thyroid pathology, hypercorticism, etc.). Immunosuppression of any etiology plays an important role in the pathogenesis of seborrheic dermatitis, as well as other diseases caused by opportunistic yeast-like fungi. So, seborrheic dermatitis is an early marker of HIV infection. Its symptoms are often observed against a background of severe somatic diseases, hormonal disorders, in patients with atopic dermatitis.
Symptoms of seborrheic dermatitis
Depending on the localization and severity of the inflammatory process, several clinical and topographic types of seborrheic dermatitis are distinguished:
- Seborrheic dermatitis of the scalp:
- "Dry" type (simple dandruff);
- "Fatty" type (stearic, or waxy dandruff):
- "Inflammatory" (exudative) type.
- Seborrheic dermatitis of the face,
- Seborrheic dermatitis of the trunk and large folds
- Generalized seborrheic dermatitis.
- Seborrheic dermatitis of the scalp
- Dry "type (idle dandruff), or pityriasis sicca
Dandruff is a chronic lesion of the skin of the scalp, characterized by the formation of parakeratotic scales without signs of inflammation. In these cases, as with ichthyosis, scales are primary vysypnye elements. The appearance of dandruff is the earliest sign of the development of seborrheic dermatitis of the scalp.
Dandruff occurs in the form of small foci, mainly in the occipitol parietal region, but can quickly spread to the entire scalp. The boundaries of the lesion are not clear. Characteristic for seborrhea hyperplasia and hypersecretion of sebaceous glands is absent. Peeling is otrigious, scales are dry, friable, grayish-white, easily detached from the surface of the skin and contaminate the hair, as well as outer clothing. Hair is also dry. Typically, the absence of inflammatory phenomena and subjective disorders.
"Bold" type, or pityriasis steatoides
Oily (stearic, or waxy) dandruff occurs against the background of increased sebum, so scales have a sebaceous appearance, a yellowish tinge, are glued together, more firmly retained on the skin than with dry dandruff, and can form stratifications. From the surface of the skin flakes are usually separated by large flakes. Hair looks greasy. Itching can also be observed, erythema and excoriation.
Inflammatory or exudative type
On the scalp appears flaky erythema, which is insignificantly infiltrated, and spotty-plaque rashes of a yellowish-pink color with distinct contours are formed. They can merge into extensive psoriasis-shaped foci that capture almost the entire scalp. In the region of the forehead and temples, a distinct, slightly elevated edge of the lesion is located below the hair growth line in the form of the "seborrheic crown" (corona seborrheica Vnnae). The surface of the elements is covered with dry, otrigious or greasy scales. Patients are troubled by itching.
In some patients, serous or dairy scaly crusts of a yellowish-gray color appear on the surface of the foci, which have an unpleasant odor, after removing which the wetting surface is exposed.
The process from the scalp often goes over to the forehead, neck, ears and parotid zones. In the folds behind the auricles, deep painful cracks can be observed, and sometimes regional lymph nodes increase.
Seborrheic dermatitis of the face
The medial part of the eyebrows, the bridge of nose, and the nosocutaneous folds are affected. There are itchy patchy-plaque flaky elements of pinkish-yellowish color of various sizes and shapes. In the folds, painful cracks, layered scaly crusts can arise. Eruptions on the face, as a rule, are combined with lesions of the scalp and eyelids (marginal blepharitis). At men in the field of a mustache and on a chin the superficial follicular pustules can be observed also.
Seborrheic dermatitis of the trunk
The lesion is localized in the sternum, in the interscapular zone along the spine. Rashes are represented by yellowish or pinkish-brownish follicular papules covered with fat scaly crusts. As a result of their peripheral growth and fusion, faintly infiltrated foci are formed with distinct, large-faceted or oval outlines, paler in the center and covered with delicate scaly scales. On the periphery of the foci, you can find fresh dark red follicular papules. Due to the central resolution, some plaques can acquire ring-shaped, garland-like outlines.
In large folds of the skin (axillary, inguinal, anogenital, under the mammary glands, in the navel) seborrheic dermatitis manifests itself clearly limited erythema or plaques from pink with a yellowish hue to a dark red color, the surface of which is flaky, and sometimes covered with painful cracks and scaly- crusts.
Generalized seborrheic dermatitis
Foci of seborrheic dermatitis, increasing in area and merging can lead to the appearance in some patients of secondary erythroderma. Skin with a bright pink color, sometimes with a yellowish or brownish tinge, is edematous, large folds are exaggerated, cracks are observed, exfoliative peeling. There may be microveiculation, wetting (especially in the folds of the skin), scaling of scaly crusts. Pyococcal and candida microflora are often attached. Patients are concerned about severe itching, fever. Seborrheic dermatitis can be accompanied by the appearance of polyadenitis, worsening of the general condition of patients, which is an indication for hospitalization.
The course of seborrheic dermatitis is a chronic relapsing disease, the disease worsens in the winter season, and in summer almost complete remissions are observed. Seborrheic dermatitis, not associated with HIV infection, usually proceeds easily, affecting individual areas of the skin. Seborrheic dermatitis associated with HIV infection is characterized by a tendency to more severe and generalized, a common lesion of the trunk skin, large folds, the appearance of atypical manifestations of follicular pustules (like plaque eczema), high frequency of generalized seborrheic dermatitis, resistance to therapy, frequent relapses.
Complications of seborrheic dermatitis
Seborrheic dermatitis can be complicated by such conditions: eczematization, attachment of secondary infection (yeast-like fungi of the genus Candida, streptococci), sensitization to physical and chemical irritants (to high temperature, some synthetic tissues, external and systemic medicines).
Seborrheic dermatitis is diagnosed on the basis of a characteristic clinical picture. Differential diagnosis should be carried out between seborrhoeic psoriasis, allergic dermatitis, perioral dermatitis, seborrhoeic papular syphilis, smooth skin mycosis, lupus erythematosus, clinical keratosis, ichthyosis, facial scarring, lymphoma of the face and scalp, streptoderma of the scalp and other dermatoses. In case of isolated localization of the process on the scalp, it is also necessary to remember the head lice.
How to treat seborrheic dermatitis?
The main attention in the treatment of each patient who suffers from seborrheic dermatitis should be given to the identification of individually significant factors in the pathogenesis of seborrheic dermatitis and, if possible, their correction.
Etiotropic treatment of seborrheic dermatitis consists in the systematic use of external antimycotic agents acting on P. Ovale. These include ketoconazole (Nizoral) and other azole derivatives - clotrimazole (Clotrimazole, Kanesten, Candide, etc.), miconazole (Dactarin), bifonazole (Mycospor), econazole (Pevaril, etc.), isoconazole (Travogen), etc., terbinafines (Lamizil, etc.), olamines (Batrafen), amorolfine derivatives, zinc preparations (Kuriozin, Regecin, etc.), sulfur and its derivatives (selenium disulphide, selenium disulphide, etc.), tar, ihtiol. For the treatment of seborrheic dermatitis of smooth skin and skin folds, these fungicides are used in the form of a cream, ointment, gel and aerosol. When attaching pyogenic infection, antibacterial drugs are prescribed - creams with antibiotics (Baneocin, Fucidine, Bactroban, etc.), 1-2% aqueous solutions of aniline dyes (brilliant green, eosin, etc.).
When the scalp is affected, these funds are used more often in the form of therapeutic shampoos, which should be applied several times a week. The course of medical shampoos is usually 8-9 weeks. It should be remembered that these shampoos need to be applied with the mandatory application of foam for 3-5 minutes, and then - to wash off.
In the "dry" type of lesions of the scalp, it is inappropriate to use alkaline soaps and shampoos, as well as alcohol-containing products, as they degrease and dry the skin, enhance its peeling. Most preferably shampoos containing azoles (Nizoral, Sebozol) or zinc preparations (Friederm-zinc, Kerium-Cream), sulfur and its derivatives (Selezhel, Derkos dandruff for dry scalp ).
With hypersecretion of the sebaceous glands, antiseboric agents are effective, since removing from the skin of the lipid film means the elimination of a favorable environment for the life of P. Ovale. Rational is the use of detergents containing anionic and nonionic detergent acids (for example, lemon) and normalizing the pH of the skin surface. In the case of a fatty type, shampoos containing azoles ("Nizoral", "Sebozol", "NodeD. C "," Node. ("Friederm-tar"), ichthyol ("Curtiol", "Curtiol S"), sulfur and its derivatives (shampoo "Derkos for dandruff for oily scalp") and other products with antifungal activity ( "Saliker", "Kelyual D.S.", "Kerium-intensive", "Kerium gel", etc.).
In the inflammatory type of seborrheic dermatitis, a quick therapeutic effect is provided by solutions, emulsions, creams, ointments, aerosols containing glucocorticosteroid hormones (Elokom, Advantan, Lokoid, etc. Or combined agents (Pimafucort, Triderm, Travocort) with timely prescription of external antifungal agents. , that these drugs are prescribed for a short time within 7-10 days, and fluorinated glucocorticosteroids are not preferred.
Traditionally, keratolytic agents are used in the treatment of seborrheic dermatitis in low concentrations: salicylic acid (for the scalp - shampoos "Phytosilic", "Phyto-saret", "Salicher", "Kerium-Intensive", "Kerium-Cream", "Kerium-gel" , "Squafan") and resorcinol. Rational is the use of combined external drugs containing antimycotics, glucocorticoids and exfoliating agents.
After the onset of remission, careful care of the skin and scalp is shown. For washing recommend "soft" shampoos that do not change the pH of the skin surface ("Ecoderm", "Elijon", "pH balance", etc.). Also recommend a preventive head wash with detergents, including antifungal agents, once every 1-2 weeks.
Critical to the treatment of severe forms of seborrheic dermatitis has individual pathogenetic therapy. However, it is far from always possible to identify and eliminate factors that play a pathogenetic role in the onset of seborrheic dermatitis. Assign inside or intramuscular calcium preparations in combination with vitamin B6. In severe, generalized and resistant to external treatment of seborrheic dermatitis, systemic administration of azole agents (Ketoconazole - Nizoral 240 mg / day for 3 weeks or itraconazole - Orungal 200 mg / day for 7-14 days) is shown. In acute cases of generalized seborrheic dermatitis, in extreme cases, systemic steroids are prescribed (a rapid clinical effect is usually achieved with taking 30 mg prednisalone per day) concomitantly with active external or general therapy with antimycotics. In cases of secondary infection and the development of complications (lymphangitis, lymphadenitis, fever, etc.) antibacterial agents of a wide spectrum of action are shown. Sometimes patients who have seborrheic dermatitis are prescribed isotretinoin and selective phototherapy (UV-B).