Hives are an allergic reaction that causes 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. They may come and go for days or weeks, sometime longer.
Hives are harmless except when they cause throat swelling or breathing problems.
If there is a shortness of breath, wheezing or dizziness you should have someone take you to seek medical attention immediately. If your hives appeared following use of a medication, call your doctor today before taking another dose. The hives can be a reaction to almost anything, including cold, heat, foods, infections, medications and even emotional tension. Unless you already have a good idea what is causing the hives or if a new drug has just been taken, doctors are unlikely to be able to determine the cause. Most often a search for the cause is fruitless.