What are Hives?
Hives are itchy, red welts or small bumps that last from 15 minutes to several hours. They usually appear suddenly and leave no trace when they disappear. Crops of Hives may appear several times a day as swollen pink bumps or raised lesions on the skin. They may come and go for days or weeks, sometimes longer. Hives are harmless except when they cause throat swelling, which is rare but requires immediate treatment. Angioedema is a hive-like swelling of the lips, eyes, or other tissue. Angioedema may take 24 hours or more to go away.
What causes Hives?
Hives are usually the result of an allergic reaction. This causes release of histamine from cells in the skin. Histamine causes the blood vessels to dilate and leak fluid into the surrounding tissue causing the skin to swell. This irritates nerve endings resulting in itching. In severe reactions, feelings of nausea, vomiting, and dizziness may be present.
Medications such as penicillin, aspirin, or codeine can cause Hives in allergic people. Certain foods commonly trigger Hives. Infections such as infectious mononucleosis, urinary tract infections, colds, infected teeth or sinuses can also cause Hives. Only very rarely have Hives been the result of an internal disease such as an overactive thyroid. Occasionally physical agents such as pressure, heat, sunlight, exercise, or cold may cause Hives.
Since medications are the most common cause of Hives, please list all the medicines you’ve been taking, including headache tablets, allergy pills, and medicines for stomach discomfort, laxatives, tranquilizers, cough medicines, pain killers, and herbal medicines. List any unusual foods you ate in the last 2 days before the Hives first appeared. It is important to search for a cause of Hives if you are having other symptoms such as fever or joint pains, or if you have had Hives more or less daily for more than 6 weeks.
How can I treat Hives?
Diagnosis is the first step in treating hives and this can be done by visual inspection of the affected area or, in some cases, by a skin biopsy with one of our skin experts. This is particularly helpful in cases when hives are associated with vasculitis (inflammation of the blood vessels). The mainstay of treatment is oral antihistamines. At times, steroids may be used to bring severe cases under control.
Some other tips:
- Avoid hot baths, heavy physical exertion, and becoming overheated, especially near bedtime. If you stay relatively cool, the Hives will often be less uncomfortable.
- Avoid wearing tightly fitted clothes or clothes made from rough fabrics such as wool or coarse knits; as these may often worsen the itching of Hives. Clothes worn next to the skin should be soft and smooth.
- Pat dry after bathing or showering. Vigorous rubbing of the skin, such as toweling off after a bath should be avoided.
- Keep skin moisturized, as dryness of the skin often worsens Hives. It is almost always helpful to moisturize the skin frequently, since this decreases the amount of friction between your skin and your clothing.