Hives are a common skin condition that may occur in as much as 10-15% of the population at some time in their lives. The skin outbreaks (or lesions) can have a variable appearance but they are almost always itchy and red. At times there is a “wheal and flare” response, with a raised pale swelling 1/8 to 2 inches in diameter surrounded by a red flare. At other times the skin outbreaks consist of lesions that are raised and red all over. Individual lesions can come and go over several hours or last for several days. Excessive scratching can cause a breakdown of the skin and the formation of scabs.
Hives can occur on all parts of the body but in certain areas they tend to have a different appearance. On thick skin (such as the palms of the hands, soles of the feet, or scalp) they can be itchy or even painful with a swelling that is less well defined. On soft areas of the skin such as around the eyes and mouth or on the genitalia, all that often occurs is a poorly circumscribed swelling without the discrete red areas (this is called angioedema by doctors). There is another group of diseases that go by the name “angioedema” in which there is a localized swelling without redness or itchiness (this can be hereditary or caused by a class of blood pressure medications called “ACE inhibitors”).
Sometimes hives can involve non-skin areas of the body such as the tongue and back of the throat. This is a potentially dangerous and requires special precautions. As a rule if the hives have been present for a number of weeks and involvement of the mouth has not occurred it is unusual that they would spread to this location. Rarely hives can involve the stomach and intestines and produce nausea, cramps and diarrhea. What makes hives confusing to patients and doctors alike is that hives can change the way they manifest themselves over time.