Diseases characterized by high fever (e.g., scarlet and typhoid fevers), malnutrition, chemotherapy, and glandular disorders can all cause balding. Treatment of the disease or dysfunction will usually halt the loss of hair, and if the scalp and hair follicles are not severely damaged, hair will usually regrow spontaneously. Scalp infection, oiliness or dirtiness of the scalp and hair, and excessive teasing and lacquering of hair are also conducive to baldness. Alopecia areata is a disease of unknown origin characterized by noninflamed bald patches in the scalp hair and beard. It is recurrent but is usually of short duration.
Lack or loss of hair, either permanent (from destruction of hair follicles) or temporary (from short-term follicle damage). Male pattern baldness is inherited and affects up to 40percnt of men; treatments are transplanting of follicles from areas where hair still grows and application of drugs (e.g., minoxidil) to the scalp. Other causes of permanent baldness are skin diseases and injuries, inborn lack of hair development, and severe follicle injury. Temporary hair loss may follow high fever or come from X rays, drugs, malnutrition, or endocrine disorders. Alopecia areata, with sharply outlined patches of sudden complete baldness, is also usually temporary.
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