Hives - Urticaria

Overview

Hives are extremely itchy raised bumps that appear on the skin. They can resemble mosquito bites or have an oddly shaped appearance. They are often called wheals. The official name for hives is urticaria. A wheal typically last less than 24 hours. Urticaria can be acute or chronic. Urticaria is considered chronic if it lasts more than six weeks. There are many causes for urticaria. Acute urticaria can be caused by insect bites, food, infection or medication/supplements. Chronic urticaria can also be caused by infections or medication but can also be caused by many other factors including physical triggers such as stroking the skin, pressure, cold, water, sun and exercise.

Diagnosis

The diagnosis of hives can usually be made with a thorough history and physical examination although sometimes a skin biopsy may be necessary. It is important that you inform your treating physician of all over the counter medications, vitamins and herbal supplements as well as prescription medications you have taken. It is also important to reveal all current and previous medical diagnoses. For chronic urticaria, blood work is often ordered to rule out infection, autoimmune disease or other metabolic causes. An X-ray of the chest, sinuses or teeth may also be used to look for occult infection.

Management

Hives occur because of release of histamine from cells within the skin. Therefore, the mainstay of management of the intense itch associated with most hives is oral antihistamines. Antihistamines include H1 blockers such as diphenhydramine (Benadryl), loratidine (Claritin), zytrizine (Zyrtec) and H2 blockers such as cimetidine (Tagamet) and ranitidine (Zantac). High doses and a mix of several antihistamines is often required to control itching. Other oral agents called leukotriene receptor antagonists may also be used. Important treatment, however, is soothing the skin with the use of anti-itch lotions based on camphor, menthol or phenol such as Sarna and Calamine lotion. The use of oral steroids is rarely necessary.

Coping

Living with hives can be very challenging because of the intense itch. Following recommendations regarding use of oral antihistamines and topical skin soothing agents will help. The majority of hives are transient and resolve within a few days or weeks. For those episodes of longer duration, laboratory tests can provide reassurance that there is no underlying infection or illness. If a medication is suspected as the cause, the medication may need to be stopped under the guidance of the prescribing physician. Even if the offending agent is removed the hives generally do not stop immediately but may take weeks to vanish depending how long it will take for the offending agent to “wash out” of your body.

Prevention

Prevention of acute episodes of hives is rarely possible especially when the underlying cause is unknown. For chronic urticaria caused by physical stimuli, avoidance of these physical factors such as cold, pressure, water and sun can reduce flares. Continuing use of oral antihistamines can also be preventative.

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