The guidelines, The Diagnosis and Management of Urticaria: A Practice Parameter, were developed by a joint task force of allergists and are published as a supplement to the December issue of Annals 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 six weeks. Some cases are chronic, lasting more than six weeks.
"Urticaria, commonly known as hives, is one of the most common dermatological conditions seen by allergists," said co-editor Dr. David L. Goodman, Allergy and Asthma Consultants of the Rockies, Englewood, Colo. "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, Allergy and Asthma Consultants of the Rockies, Englewood, Colo.
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 exam 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 one out of five or six 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. Non-sedating, 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 side 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 American College of Allergy, Asthma and Immunology, the American Academy of Allergy, Asthma and Immunology and the Joint Council of Allergy, Asthma and Immunology.
A free patient brochure, Advice from your Allergist on Urticaria, is available on the Internet at www.medem.com or by calling the ACAAI toll free number at (800) 842-7777.
The ACAAI is a professional medical organization comprised of 4,100 qualified allergists-immunologists and related health care professionals. The College is dedicated to the clinical practice of allergy, asthma and immunology through education and research to promote the highest quality of patient care.
© The American College of Allergy, Asthma & Immunology