Fewer Children May Be Diagnosed as Doctors
Told Not to Rely Solely on Standard
Skin and Blood Tests
Parents
who have eliminated foods from their children's diets based on allergy tests
alone may find that some are safe to eat after all. The National Institute for Allergy
and Infectious Diseases issued the first clinical guidelines for diagnosing and treating food
allergies Monday, saying that blood or skin tests aren't sufficient when making a diagnosis.
An
allergy should be suspected if someone has a reaction within minutes or hours
of eating a food, according to the guidelines. Physicians should then take a detailed
medical history, conduct a physical exam and confirm the allergy with a skin-prick test, in which
tiny drops of the suspected allergen are pricked into the skin, usually in the forearm, to see if
red wheals form. None of those steps is definitive by itself, the recommendations say, which will
likely to lead to fewer diagnoses.
For a correct
diagnosis, "it takes a combination, and in some cases an oral food
challenge," in which patients are exposed to tiny amounts of the suspect food under close
medical supervision, says Hugh A. Sampson, director of the Jaffe Food Allergy Institute at Mount Sinai
Medical Center in New York and one of the authors.
The
guidelines, published this week in the Journal of Allergy and Clinical Immunology,
are aimed at resolving wide discrepancies in diagnosing and treating food allergies among
allergists, dermatologists,
gastroenterologists, pulmonologists and emergency physicians, as well as pediatricians and internists. More than 30
professional organizations, federal agencies and patient groups were involved in the report, which
was in the works for two years.
The research company Rand Corp. contributed a review of scientific
studies.
Roughly
4% of children under age 18—about three million—reported having food
allergies in 2007, an 18% increase from 1997, according to the Centers for Disease Control and Prevention.
Milk, eggs, peanuts, wheat, soy, fish and shellfish are the most common culprits, although more than 170
other foods have been reported to cause allergic reactions. Symptoms can range from eczema and
hives to asthma, inflammation of the esophagus, diarrhea, vomiting and life-threatening
anaphylaxis, in which major body systems quickly shut down.
The
prevalence of food allergies has been difficult to gauge because of different
standards in diagnosing and a proliferation of tests being marketed to doctors. Some tests have not been
scientifically validated, experts say, and some doctors lack the expertise to interpret those that
have been. The report did not state that kids were being misdiagnosed, but it did note that
erroneous diagnoses could affect their nutritional well-being and quality of life.
Melinda Beck at HealthJournal
The information aims to provide educational purpose
only. Anyone reading it should consult physician before considering treatment
and should not rely on the information above.
