hives

hives
/huyvz/, n. (used with a sing. or pl. v.) Pathol.
any of various eruptive conditions of the skin, as the wheals of urticaria.
[1490-1500; orig. Scots; of obscure orig.]

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Allergic skin reaction in which slightly raised, flat-topped, very itchy swellings appear suddenly.

The acute form, probably most often caused by food allergies, subsides in 6–24 hours, but the chronic form, believed to be due to emotional and mental stress, lasts much longer. Acute hives may also be triggered by drugs, especially penicillin, inhaled allergens or toxins, or diseases. Treatment involves identifying and avoiding the allergen; epinephrine and antihistamines may help the acute skin symptoms.

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also called  urticaria 

      a hypersensitive skin reaction characterized by the sudden appearance of very itchy, slightly raised, smooth, flat-topped wheals and plaques that are usually redder or paler than the surrounding skin. In the acute form, the skin lesions generally subside in 6 to 24 hours, but they may come and go and persist much longer in the chronic form.

      Several specific causes of hives, as well as variant forms of its typical skin lesions, are denoted by qualifying the term urticaria with a descriptive word. Examples include urticaria bullosa, a rare type of allergic reaction characterized by the appearance of bullae or vesicles (large or small blisters); solar urticaria, produced by exposure to sunlight; and urticaria subcutanea, caused by swelling of the tissues underlying the skin.

      Allergy (immune system disorder) to a specific food is probably the most frequent cause of acute urticaria; fish, eggs, berries, and nuts head the list of common offenders. Hives may also be triggered by drugs, especially penicillin, by biologicals containing proteins, and by inhalants (e.g., pollens, insecticides, dust, feathers). Less frequently, physical agents, such as cold, heat, insect bites, and mechanical injury, as well as parasitic and other infectious diseases, may be triggers. Emotional and mental stresses are believed to be major and contributing causes of chronic urticaria.

      The mechanism by which psychogenic factors give rise to chronic urticaria is not clear, but the overall sequence of biological events that triggers acute urticaria has been clarified. The mast cells (mast cell) lining the blood vessels contain histamine, which is released following contact of the mast cells with the irritating substance. Histamine in turn increases the permeability of the capillaries, so that plasma escapes into the spaces between the cells of the skin, giving rise to swellings that constitute the wheals and plaques. The itching is also thought to be caused by histamine.

      Hives appear to show a familial incidence and are more common in persons with a history of allergic reactions. Treatment involves identification and subsequent avoidance of the allergen; administration of epinephrine and antihistamines may help to control the acute skin symptoms.

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Universalium. 2010.

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Look at other dictionaries:

  • Hives — Hives, n. [Scot.; perh. akin to E. heave.] (Med.) (a) The croup. (b) An eruptive disease (Varicella globularis), allied to the chicken pox. [1913 Webster] …   The Collaborative International Dictionary of English

  • hives — c.1500 hyvis itchy condition of the skin, origin unknown. Some writers connect it with heave because hives erupt out from the skin, but the phonetics of that are difficult to explain …   Etymology dictionary

  • hives — [ haıvz ] noun uncount a medical condition in which you get red ITCHY spots on your skin, often because you have eaten a particular food. The medical name for this is urticaria …   Usage of the words and phrases in modern English

  • hives — [hīvz] n. [orig. Scot dial.] [with sing. or pl. verb] an allergic skin condition characterized by itching, burning, stinging, and the formation of smooth patches, or wheals, usually red; urticaria …   English World dictionary

  • Hives — The Hives Sänger „Howlin“ Pelle Almqvist beim Southside Festival 2004 Gründung 1993 Genre Alternative Rock, Garage Rock …   Deutsch Wikipedia

  • Hives —  Pour l’article homonyme, voir The Hives.  Hives …   Wikipédia en Français

  • Hives — A raised, itchy area of skin that is usually a sign of an allergic reaction. It can be rounded or flat topped but is always elevated above the surrounding skin. It reflects circumscribed dermal edema (local swelling of the skin). The hives are… …   Medical dictionary

  • hives — noun plural but singular or plural in construction Etymology: origin unknown Date: circa 1500 an allergic disorder marked by raised edematous patches of skin or mucous membrane and usually intense itching and caused by contact with a specific… …   New Collegiate Dictionary

  • hives — (hīvz) An eruption of the skin …   Dictionary of microbiology

  • hives — noun Itchy, swollen, red areas of the skin which can appear quickly in response to an allergen or due to other conditions. Syn: urticaria, nettle rash …   Wiktionary

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