News tagged with hives
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Urticaria (from the Latin urtica, nettle (whence It. ortica, Sp. ortiga, Pg. urtiga, Fr. ortie) urere, to burn) (or hives) is a kind of skin rash notable for pale red, raised, itchy bumps. Hives is frequently caused by allergic reactions; however, there are many non-allergic causes. Most cases of hives lasting less than six weeks (acute urticaria) are the result of an allergic trigger. Chronic urticaria (hives lasting longer than six weeks) is rarely due to an allergy. The majority of patients with chronic hives have an unknown (idiopathic) cause. Perhaps as many as 30–40% of patients with chronic idiopathic urticaria will, in fact, have an autoimmune cause. Acute viral infection is another common cause of acute urticaria (viral exanthem). Less common causes of hives include friction, pressure, temperature extremes, exercise, and sunlight.
Weals (raised areas surrounded by a red base) from urticaria can appear anywhere on the surface of the skin. Whether the trigger is allergic or non-allergic, there is a complex release of inflammatory mediators, including histamine from cutaneous mast cells, resulting in fluid leakage from superficial blood vessels. Wheals may be pinpoint in size, or several inches in diameter. Angioedema is a related condition (also from allergic and non-allergic causes), though fluid leakage is from much deeper blood vessels. Individual hives that are painful, last more than 24 hours, or leave a bruise as they heal are more likely to be a more serious condition called urticarial vasculitis. Hives caused by stroking the skin (often linear in appearance) are due to a benign condition called dermographism.
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Prebiotic supplements in infant formula may help to prevent eczema, according to a systematic review published in The Cochrane Library. However, the review highlights a lack of high quality evidence for the effects of pre ...
Health Mar 27, 2013 | not rated yet | 0
An international team of researchers has found that a once-a-month, high-dose injection of a commonly used asthma drug is highly effective in treating teens and adults chronically afflicted with hives and severe, itchy rash. ...
Immunology Feb 24, 2013 | 5 / 5 (2) | 0 |
(HealthDay) -- Emily Kloser wasn't too concerned when her son's doctor first told her he had signs that pointed to a future with allergies.
Health Aug 03, 2012 | not rated yet | 0
If you are a steak lover, enjoy your meat while you can. An article by Susan Wolver, MD, and Diane Sun, MD, from Virginia Commonwealth University in the US, and colleagues, explains why if you have been bitten by a tick, ...
Immunology Jul 24, 2012 | 5 / 5 (1) | 0
(HealthDay) -- Nearly one in four people develops hives at some time or another, and they can be triggered by hot summer weather.
Immunology May 30, 2012 | not rated yet | 0