Hives (urticaria)

Urticaria, also known as hives, is a dermatological medical condition in which red itchy bumps form on the skin. Hives are usually caused by an allergic reaction to a food or medication. People with allergies are more prone to develop urticaria; stress and infections can also cause it. Physical exercise may also cause hives.

Symptoms

Itching and the formation of red welts, called wheals, typify hives. The wheals have clearly defined edges and appear individually or eventually group together forming large reddish formations. A wheal when pressed in the center will turn white: this is called blanching. The wheals can disappear within minutes or remain for hours. "A hive often will go away in 24 hours or less, but bouts can last longer."

Examination

A healthcare provider can visually diagnose the presence of hives, and tests can determine whether the cause is an allergy.

Treatment

No treatment may be needed for mild hives. Patients can take an antihistamine such as diphenhydramine to help reduce the itching and swelling. Patients who have throat swelling due to hives may receive epinephrine (adrenaline) or steroids. In some severe cases those same medications may be used to treat the condition.

For chronic urticaria, omalizumab is a "an anti-IgE; a recombinant humanised monoclonal antibody which specifically binds to the C epsilon3 domain of immunoglobulin (Ig) E, the site of high-affinity IgE receptor binding"that may help.

Potential complications

Complications include anaphylaxis and swelling in the throat.