Urticaria May be a Symptom of Serious Illness

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New Guidelines Say Urticaria May be a Symptom of Serious Illness

January 3, 2001

ls of Allergy, Asthma and Immunology/MedscapeWire

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According to new medical guidelines developed by a joint task force of

allergists, as many as 15% to 24% of the US population will experience urticaria

or angioedema during their lifetime, which can be symptoms of an allergic

reaction, a common viral infection, or a serious illness.

The guidelines, The Diagnosis and Management of Urticaria: A Practice Parameter,

are published as a supplement to the December issue of ls of Allergy, Asthma

and Immunology, the scientific journal of the American College of Allergy,

Asthma and Immunology (ACAAI). Most cases of urticaria are acute, lasting from a

few hours to less than 6 weeks. Some cases are chronic, lasting more than 6

weeks.

" Urticaria, commonly known as hives, is one of the most common dermatological

conditions seen by allergists, " said co-editor Dr. L. Goodman, of Allergy

and Asthma Consultants in Englewood, Colorado. " Traditional allergies to foods

or medications and viral illness are frequent causes of acute urticaria. "

" Chronic urticaria is more complex, given the vast number of potential triggers

and multiple causes, and the difficulty in identifying them. The interaction

between the immune system and some autoimmune diseases, such as autoimmune

thyroid disease, has come to light as a potential important trigger for chronic

urticaria, " Dr. Goodman said.

Urticaria usually strikes suddenly. First the skin itches, then it erupts into

red welts. The itching may be severe, sometimes painful or burning, and can keep

people from working or sleeping.

" Urticaria is not just an allergic disease. It can be caused by metabolic

diseases, medications, infectious diseases, autoimmune disease, or physical

sensitivity, " said co-editor Dr. Alan A. Wanderer, also of Allergy and Asthma

Consultants.

In contrast to urticaria, angioedema is a deeper, subcutaneous swelling, usually

in the areas of the face or mucous membranes involving the lips or tongue. If

angioedema involves the upper respiratory tract, life-threatening obstruction of

the laryngeal airway may occur.

Many patients with acute urticaria seek care from their primary care physicians

who, in many instances, can determine the probable cause by reviewing the

patient's history and performing a physical examination and a few simple

laboratory tests.

" The problem is first of all, making sure you are dealing with the correct

diagnosis of urticaria, and not some other disease process that mimics

urticaria. Chronic urticaria with angioedema presents a challenge in its

treatment in that it often requires long-term follow-up, " Dr. Wanderer said.

" Treatment of chronic urticaria/angioedema is more difficult because symptoms

can persist for a long duration and affected patients are frustrated as they

expect their physician to pinpoint the cause of their symptoms. Unfortunately,

the cause can be established in only 1 out of 5 or 6 adult patients with chronic

urticaria, " he said.

According to the literature on which the guidelines were based, the duration of

chronic urticaria/angioedema cannot be predicted. Spontaneous remissions often

occur within twelve months, but many patients continue to have symptoms for

years.

" It's common for patients with chronic urticaria or angioedema to go from one

physician to another, in part, because the physicians themselves are frustrated

identifying the cause of the problem. If a patient has a perplexing form of

urticaria or angioedema, it may be useful for them to seek out an allergy

specialist to make sure the more serious, underlying diseases have been ruled

out, " Dr. Wanderer said.

" Some mastery of the treatment is important in terms of identifying the right

combination of medications that can suppress the urticaria symptoms to the best

extent possible with the least side effects, " he said.

The mainstay of treatment for urticaria/angioedema is the use of antihistamines.

Nonsedating, second generation antihistamines are usually preferred. When these

fail, first generation antihistamines, such as hydroxyzine, diphenhydramine, or

doxepin, may be effective, but should be used with caution because of their

adverse effects. The new medical guidelines were designed both for the allergy

specialist and primary care physicians. Diagnostic and management algorithms

give physicians a better understanding of acute and chronic urticaria and

provide a simplified method for diagnostic work-up.

The peer-reviewed, evidence-based practice parameter is one of a series

developed by the Joint Task Force on Practice Parameters, representing the

ACAAI, the American Academy of Allergy, Asthma and Immunology, and the Joint

Council of Allergy, Asthma and Immunology. More information is available on the

ACAAI Wev site at http://allergy.mcg.edu/param/param.html.

http://rheumatology.medscape.com/MedscapeWire/2001/0100/medwire.0103.New.html