Hives, Urticaria, and Angioedema

Urticaria, also known as hives, are raised, red-pink skin lesions that are very itchy and transient. They typically last less than 24 hours in a single location without leaving residual marks or bruising. Small hives can coalesce into large patches of hives. Urticaria can be divided into two categories: acute and chronic. Acute urticaria is defined as outbreaks of urticarial lesions that do not persist beyond 6 weeks. Chronic urticaria is defined as the recurrence of hives on a near daily basis for more than 6 weeks. It estimated that hives will occur in approximately 16% of the population at sometime during their lives. Women tend to get urticaria more than men and young people are more predisposed to get them.

Angioedema is a deeper swelling of the skin and can accompany hives, but can also occur independent of hives.

What causes urticaria and angioedema?

There are many potential causes which may or may not be allergic in origin. Allergic causes include dust mites, molds, pollens, animals, foods and chemicals. Urticaria can be secondary to other diseases such as lupus, thyroid disease, mastocytosis, liver disease, infections and autoimmune diseases. Medications can be a source of hives and angioedema. Certain types of urticaria and or angioedema can be caused by familial diseases. There are exercise-induced hives which may be related to other allergic items such as foods or contact allergens.

Should I see a doctor for my hives and/angioedema?

You should be evaluated if your hives do not respond to over the counter medication, cause discomfort or affect your quality of life.  Hives that cause bruising should be evaluated since they are an unusual finding and may point to the presence of a systemic disease. Hives accompanied by non-cutaneous symptoms such as difficulty breathing, dizziness or stomach pain, should be seen by a physician immediately.

Angioedema should be evaluated by a physician. If angioedema causes swelling of the tongue or throat or is accompanied by difficulty breathing, swallowing, speaking or abdominal discomfort, you should seek medical attention immediately.

How are urticaria and angioedema evaluated?

A thorough history of symptoms is very important with emphasis on possible triggers in daily activities or diet intake. A diary of symptoms is very helpful. Family history is important to evaluate hives. Physical exam can help to differentiate between different types of hives and or angioedema, as well as detect other diseases that might be cause the symptoms.

Laboratory tests are helpful to evaluate for other conditions. Allergy tests by either skin or blood can determine if allergies are involved. Allergy patch testing can help detect contact triggers for hives. Occasionally a skin biopsy is needed to determine the cause.

How are urticaria and angioedema treated?

If allergies are involved, avoiding known allergens will help to prevent symptoms. Initial treatment generally includes the use of oral anti-allergy medications. A patient may require multiple medications for control of symptoms. If there is an underlying medical cause, this will need to be treated. In addition, if there are severe life threatening symptoms, an emergency treatment plan needs to be in place which may include the use of injected adrenaline, like Epipen.

Xolair is a new treatment option for patients with chronic hives of unknown cause who have not responded to conventional treatment. This medication has been shown to be highly effective.