itch(redirected from Mad itch)
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a distressing sensation caused by constant weak irritation of the cutaneous nerve endings that are pain receptors and accompanied by the need to scratch the skin.
Itching may be stimulated by a number of metabolic products—for example, bile acids in jaundice. There is localized and universal (generalized) itching. Localized itching is found in certain inflammatory diseases of the skin. Causes of universal itching may be diseases of the skin proper, diseases of various internal organs (jaundice, diabetes mellitus); certain allergic states, and decrease in function of the sex glands. The very notion of a habitual source of itching familiar through past experience (for example, an insect bite) may produce the corresponding sensation of itching (conditioned-reflex itching). Itching may be chronic or come in attacks lasting from a few hours to many weeks. Scratching leads to disruption of the integrity of surface layers of the skin and to infection of itching areas, which may cause a secondary inflammatory disease of the skin.
Treatment of an itch consists in eliminating the disease that is causing it. Sedatives (bromine, valerian, calcium preparations) are prescribed and menthol and sea baths are applied externally. Hormone preparations are used for climacteric and geriatric itching. Localized itching can be prevented by the observance of personal hygiene.
V. S. ROTENBERG