acne(redirected from acne tropicalis)
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acne,common inflammatory disease of the hair follicles and sebaceous glandssebaceous gland
, gland in the skin of mammals that secretes an oily substance called sebum. In humans, sebaceous glands are primarily found in association with hair follicles but also occur in hairless areas of the skin, except for the palms of the hand and soles of the feet.
..... Click the link for more information. characterized by blackheadsblackhead,
yellowish or blackish plug of material accumulated in the duct of a sebaceous gland. The material consists of keratin (horny cells of the epidermis) and modified sebum (oily secretions of the sebaceous gland). Blackheads are the primary lesions in acne.
..... Click the link for more information. , whiteheads, pustules, nodules and, in the more severe forms, by cysts and scarring. The lesions appear on the face, neck, back, chest, and arms. There are several types of acne, including tropical acne, a condition of light-skinned people who are exposed to unaccustomed heat and humidity, and chloracne, a form resulting from exposure to chlorinated hydrocarbons.
The most common type is acne vulgaris, a form prevalent among adolescents. Although its exact cause is not known, it is undoubtedly related both to genetic predisposition and to the increased hormonal activity that occurs at puberty, which causes an overproduction of sebum, the oily secretion of the sebaceous glands. Exposure to external oils and grease (e.g., oil-based cosmetics or hair products, occupational use of cooking oils) can worsen the condition. There is no connection between diet and acne.
Washing the skin removes surface oils and can prevent acne from spreading. The contents of blackheads and pustular lesions should be evacuated only by a physician under proper aseptic conditions to lessen the possibility of scarring. Application of benzoyl peroxide, retinoic acid, azelaic acid, and antibiotics to the skin can clear many cases; exposure to ultraviolet light may also be used. More severe cases of acne may require oral antibiotic treatment. Treatment of the most resistant cases of acne includes the use of isotretinoin (Accutane), a drug that decreases sebaceous secretions. Isotretinoin is a well-established teratogen (i.e., it causes birth defects) and is not given to women who are pregnant. In the past dermabrasion (scraping off of the top layer of skin) was used to improve the appearance of skin scarred by acne, but such severe effects can now be avoided with proper treatment.
the name used to designate various skin eruptions that are often associated with functional disturbances of the sebaceous glands. There are several types of acne.
Common acne occurs during adolescence, usually on the face, chest, and back. It appears in the form of pink papules that may attain the size of a pea; these papules sometimes develop sebaceous plugs, or comedones, which often suppurate. The causes of common acne include hormonal changes, infections, and hereditary predisposition.
Rosacea is a type of acne that is most common in women over 40. It is marked by dilation of the capillaries of the facial skin (telangiectasis) and by the development of red papules that sometimes suppurate.
Some types of acne are caused by exposure to certain substances or by the use of some medicines. They include petroleum acne, which results from contact with petroleum products, and halogen acne, caused by the use of preparations of such halogens as bromine and iodine. Acne may also result from the use of hormonal preparations.
Acne is treated externally with suspensions, ointments, and the application of alcohol. General treatment includes physical therapy and the administration of vitamins, antibiotics, and hormones.
REFERENCEKozhnye i venericheskie bolezni, 3rd ed. Moscow, 1975. Pages 236–38,242–44.
A. S. RABEN