Urticaria or Hives are a common skin problem. 15 to 20% of people will have at least one episode of hives during a lifetime. Most of these will be of the short-lived variety (acute urticaria). Less commonly, an attack of urticaria may last for more than six to eight weeks. This is called chronic urticaria. In the acute type, a cause can usually be found; however, in chronic cases, the origin is usually not detectable.
The typical hive is a light red bump or swelling on the skin. Hives may vary from less than half an inch to many inches in diameter. As a rule, an individual hive lasts for less than 24-48 hours and then disappears. New lesions continue to develop for days, weeks, and less commonly, months.
There are a great number of causes for hives. Drugs, foods, inhalants, insect bites, creams, certain infections, emotional stress, and local injury to the skin (from such diverse causes as physical trauma, heat, cold, and sunlight) may all trigger an attack.
Laboratory tests are usually not necessary for the short-lived case. Occasionally, blood studies, urinalysis, x-rays, and allergy testing may be helpful in uncovering the cause of hives. Unfortunately, even extensive studies often fail to determine the cause in most cases of chronic (long duration) urticaria. But these studies will help to rule out the probability of a serious underlying disease.
The ideal treatment is the identification and removal of the causative agent. When this is not possible, non-specific measures should be taken. Alcohol, aspirin, heat, emotional stress, and excessive exertions should all be avoided if possible. Drug therapy affords considerable relief in most cases and antihistamines, and occasionally combinations of these are required to control an attack; however, most causes will respond to hydroxizine (Atarax). Most antihistamines cause drowsiness, especially in the first few days of use. Therefore, driving, drinking, and working around potentially dangerous machinery should be limited when first taking these agents. In the past two years, two antihistamines, Seldane and Hismanyl, which do not cause drowsiness have been approved for use.