Dec. 07--Doctors should use the combination of a detailed medical history, physical examination and medical tests when diagnosing someone with a food allergy, according to new clinical guidelines released Monday by the National Institute for Allergy and Infectious Diseases.
The guidelines were developed in response to several concerns: The diagnosis and management of food allergies vary from one clinical practice to another. Patients frequently confuse nonallergic reactions with food allergies. Studies report inaccurate results from skin and blood tests.
The guidelines -- developed with input from 34 professional organizations, federal agencies and patient advocacy groups -- are an important step in advancing the care for patients with suspected or confirmed allergies, said Dr. Leonard Bacharier, director of the pediatric allergy and immunology division at St. Louis Children's Hospital.
"The availability of a set of 'best practice' guidelines that are based upon scientific research and the opinions of experts in the field will hopefully improve the care of patients with this common and often confusing set of clinical problems," Bacharier said.
About one in 20 children and one in 25 adults have a food allergy. The true prevalence is difficult to establish because of inconsistent studies and variations in the definition of food allergy. Even incidents of anaphylaxis -- a life-threatening allergic reaction -- have been difficult to quantify because of differing diagnostic criteria in hospitals.
While difficult to quantify, food allergies may be increasing in prevalence, the guidelines state. However, "there is an unfounded belief among the public that food allergy prevalence is actually higher than it truly is."
The guidelines define food allergy and contain 43 clinical recommendations to help health care professionals make a diagnosis, customize care and treat reactions. A summary of the guidelines will be available for patients early next year.
"The main thing I feel people should know is just having a positive test for an allergy doesn't mean you're definitely allergic to a food. It has to be taken into context with a person's history," said Dr. Bradley Becker, an allergy and immunology specialist at Cardinal Glennon Children's Medical Center.
Becker stressed that an allergy specialist is needed in cases where information gathered from medical histories and physical exams isn't clear-cut. Results from blood tests also vary depending on the food and person's age.
"Doctors are ordering these readily available food allergy test panels but are not fully aware how to interpret them," Becker said.
The guidelines recommend oral food challenges -- where patients are monitored closely while receiving increasing amounts of the food over several hours -- as an accurate tool for diagnosing food allergies. Because the hospital is the safest place for a food challenge, however, the wait is long. Getting an appointment at Cardinal Glennon and St. Louis Children's can take over a year.
The guidelines also state that an epinephrine injection should be the first line of treatment in cases of anaphylaxis. Dr. Ray Davis, an allergist at Allergy Consultants, said that is too often not the case and the consequences can be deadly.
"We need to have everyone in community -- including ER doctors, school nurses and EMTs -- on the same page and fully understanding this disease," Davis said.
-----
To see more of the St. Louis Post-Dispatch, or to subscribe to the newspaper, go to http://www.stltoday.com.
Copyright (c) 2010, St. Louis Post-Dispatch
Distributed by McClatchy-Tribune Information Services.
For more information about the content services offered by McClatchy-Tribune Information Services (MCT), visit www.mctinfoservices.com.