Seborrhea

SEBORRHEA, seborrhoea (from the Latin sebum - fat and Greek rheo- to flow) (syn. seborrhagia, steatorrhoea), literally fat flow. In dermatology, S. is understood to represent two, generally distinct forms of a skin process: 1) the so-called oily, or liquid S. (seborrhoea oleosa) and 2) dry S. (seborrhoea sicca). Oily S. is characterized by abundant secretion of liquid skin fat on certain areas of the skin surface: the hairy part of the head, the face in the region of the forehead, nose, folds of the wings of the nose, nasolabial folds, less frequently in other areas (chest, scapular region). The skin in oleous S. appears greasy, shiny, as if smeared with oil, the hair is also excessively greasy and shiny; after washing the head they quickly (within 1-2 days) become greasy again. In this form of S., sebaceous glands produce an excessive amount of fat, more liquid than normal. This fat contains a larger amount of water and differs from normal in qualitative composition, since it contains an increased quantity of triglycerides (especially olein) and free oleic acid with a reduced content of cholesterol. Oleous S. is essentially a pathological state of the skin in the sense of excessive secretion of skin fat by sebaceous glands, although according to some data, the tubular glands also function intensively during this process. Excessive production of skin fat also occurs with normal skin function depending on racial and individual peculiarities of people (e.g., in Negroes, abundant secretion of skin fat with a peculiar smell from free fatty acids constitutes a normal phenomenon), as well as in connection with external factors (difference in external temperature, physical exertion, etc.) and general state of health. The abundantly secreted fat in oleous S. mixes with desquamating epidermal cells and can lead to the accumulation of fatty scales, as well as cause an inflammatory state of the skin. In newborns, an abundance of such "lamellar crusts" (crusta lactea) is noted. Dry seborrhea is not accompanied by excessive secretion of skin fat; in it, the skin and hair rather appear too dry. Dry seborrhea is characterized by abundant desquamation with small, branched scales. Dry S. of the skin of the hairy part of the head is most frequently encountered in the form of abundant desquamation with small whitish scales covering the skin and hair and falling onto clothing (the so-called "dandruff"). In some cases, desquamation with larger plate-like scales is noted (seborrhoea squamosa). The scales in dry seborrhea are nothing more than epidermal cells of the stratum corneum desquamating in excess; these cells, in the majority not fully keratinized and retaining nuclei (parakeratotic), contain an excessive amount of autochthonous epidermal fat; skin fat from sebaceous glands in the scales in dry S. is scanty, but there is an increased amount of the same fat which is secreted by the tubular glands of the skin together with sweat (hyper- and parasteatidrosis). In dry S., autochthonous epidermal fat is contained in excess in the superficial layers of the epidermis (Cedercreutz). Dry S. is nevertheless accompanied by excessive content of fat in the scales, which consist of ³/₅ fat and ²/3 epidermal cells (Pinkus). Because of this, dry S. cannot be confused with pityriasis simplex, characterized by non-inflammatory branched desquamation of keratinized epithelium. Dry S. usually begins in young age (at the 7-10th year of life) and can last for years and decades, causing characteristic premature hair loss. In some cases, dry S. leads to the development of the so-called seborrheic eczema, which it essentially represents as the initial degree. Dry seborrhea usually begins to appear on the hairy part of the skin of the head, usually not spreading to other parts of the body, but sometimes it spreads to the region of the eyebrows, beard, chest, pubic region, scrotum, etc., up to general involvement of the skin, although most often in such cases there are signs of seborrheic eczema. Histologically, in oleous S., thickening of the stratum corneum of the epidermis is noted, increase of sebaceous glands with non-dilated orifices, expansion of vessels of the papillary layer and around the ducts of sebaceous glands; around the dilated vessels, a slight infiltration of leukocytes and plasma cells. Significant accumulations of leukocytes in the intercellular spaces of the epidermis are not noted, sometimes formation of vesicular cavities, abundance of mitotic figures is observed. In dry S., slight expansion of vessels of the papillary layer; in the epidermis acanthosis with abundance of mitotic figures; abundant parakeratotic desquamation of the stratum corneum, and in the cells a significant amount of autochthonous epidermal fat is noted. The etiology of S. is unknown. Some authors consider bacteria (bottle microbes of Unna, located in groups of cocci, thin bacillus of Sabouraud, etc.) to be the cause of S., but this has never been proven in various experiments. The majority of researchers consider the cause of oleous S. to be increased function of sebaceous glands under the influence of endogenous factors. The fact that during the period of sexual maturation the function of sebaceous glands increases speaks in favor of the possibility of influence of the endocrine system, but the immediate cause of S. is not explained by this. General state of health (chlorosis, anemia, disorder of activity of the digestive tract, etc.) often has a significant influence on the appearance and persistence of seborrhea. Apparently, physiological secretion of fat by sebaceous glands and pathological changes in the function of sebaceous glands depend to a large extent on constitutional peculiarities of the organism (status seborrhoicus constitutional). The distribution and function of sebaceous glands in individual individuals differ in different areas of the body, and in different individuals there is a difference in the amount of fat produced on identical areas of the skin surface not only in adults but also in intrauterine fetuses (difference in the amount of vernix caseosa). Probably increased excretory activity of sebaceous glands can explain the appearance of acneiform formations (skin sebaceous cysts) in newborns. Increased function of sebaceous glands in intrauterine fetuses is influenced by hormones of the mother entering the fetus through placental circulation. In adults, disturbance of the function of sebaceous glands may depend on deviations in the activity of the endocrine system, as well as on disturbance of the functions of the digestive tract in the sense of delivery to the skin (sebaceous glands and epidermis) of unprocessed dietary fat, which creates a different biochemical state of the cells producing skin fat (Walter). In individuals with status seborrhoicus, increased sensitivity of the skin epithelium to various external irritations, as well as to fats, can be established. When rubbing various fats, vernix caseosa, alcohol-acetone-ether extracts of scrapings of seborrheic eczema and suspensions of bacterial cultures from foci of seborrheic eczema into the skin of such persons, inflammatory phenomena on the part of the skin were noted (in persons with oleous S. in 100%, in persons with vulgar acne in 50%), which speaks for sensitization of the skin to various fats, all the more so since with other irritants (chemical, physical, and bacterial) inflammatory phenomena were noted much less frequently (25-30%). Treatment of S. in dependence on its form, as well as on the causal factor and general state of health of the patient in each individual case has to be individualized. In the first place, general treatment has to be carried out according to the indications of the given case. In oily S., the application of ointments often causes only irritation of the skin, why ointment treatment is rarely prescribed, and in any case it is better to take Ung. Glycerini, Resorbin as a basis for ointments. More often, lotions or alcoholic solutions are prescribed. In dry S., ointments and alcoholic solutions containing fats in one form or another are present. The main medicaments for the treatment of S. are sulfur, resorcin, salicylic acid, tar preparations, chrysarobin, pyrogallol, white precipitate mercury, etc. We give a few sample prescriptions: Pr. Sulfur, pp. 12.0; Camphor, tr. 1.0, MuciL gummi arab. 6.0, Aq. rosar. + Aq. calcis aa 100.0 MDS (Aq. Kummerfeld). - Rp. Acid. salicyl. 1.0, Spirit, vini, Aether, sulfur, aa 50.0 MDS. - Rp. Tinct. benzoes 1.0, Spirit, vini 95.0, Glycerini 5.0 MDS. - Rp. Sulfur, pp. 3.0; Resorcini 1.0, Ung. cetacei 30.0 MDS. - Rp. Resorcini, Ac. salicyl. aa 1.0, 01. rusci 5.0, Sap. medic, q. s. ad emuls.; Sulf. pp. 5.0, Axung. benz. 50.0 MDS. - Rp. Sulfur, pp., Resorcini, Ichthyoli aa 2.0, Ac. salicyl. 1.0, Vaselini, Lanolini Sa ad 50.0. - Rp. Chrysarobini, Ichthyoli aa 5.0, Ung. cetacei 30.0. - For the hairy part of the head, instead of ointments, alcoholic solutions are better prescribed: Rp. Tinct. chin. compos. 5.0, 01. ricini 1.0-2.0, 01. bergamott. 0.25, Spiriti vini 100.0 MDS (instead of Tinct. chin. comp. one can take Liq. carb. deterg. 5.0 or Ac. salicyl. 1.0). In oily S., instead of 01. ricini take Glycerini 1.0-3.0.