Hives are temporary red, raised and itchy bumps and can be a sign of an allergic reaction. Most cases of hives go away on their own or can be treated with antihistamines. Skin testing can also be helpful after the hives have resolved to determine what allergen caused the reaction.
Hives that continue for more than six weeks without a specific trigger are called chronic hives. In some cases of chronic hives there is an underlying cause, although these types of hives usually are not related to a specific allergen.
Angioedema is swelling of the soft tissues of the skin and can occur with hives. Like hives, angioedema can occur in response to contact with an allergen. Either antihistamines or steroids can be used to treat the reaction if it involves the hands or feet. In some cases, angioedema will affect the face, throat and tongue, and requires immediate treatment.
Hereditary angioedema -- not associated with hives -- is a rare genetic condition that involves swelling of the hands, face, feet, stomach and airways. Special blood tests are required to make this diagnosis. Hereditary angioedema does not respond to antihistamines, but our allergists can prescribe special injections or intravenous medications to prevent and treat attacks.