Food Allergy: Not an Easy Diagnosis
PREVENTING A MISDIAGNOSIS OF FOOD ALLERGY
By Stanley Fineman, MD
SPECIAL FOR THE AJT
“What can I feed my child?” Suzie’s mom came to my office very concerned since she was just told that her 4-year-old was allergic to several of her favorite foods. Her mother explained that Suzie had problems with eczema before her first birthday, but more recently she was experiencing frequent nasal congestion and coughing. She had gone to a clinic where a blood test was drawn and Suzie’s mom was later told that Suzie was allergic to milk, peanuts and wheat. Suzie had been eating foods containing all of these ingredients so her mom was confused, particularly since peanut butter was Suzie’s favorite food. She took the results to her pediatrician who realized that it was unusual for this many food allergies to develop at the age of 4. She was then referred to me for further evaluation.
Food allergies are a serious problem and can have lethal consequences if not diagnosed and managed properly. In fact, tragically, a couple of adolescents in Metro-Atlanta have recently died after accidentally ingesting a food to which they were allergic. For many people with life-threatening food allergies, choosing what to eat can be a frightening experience.
Food allergies also impact other family members. A recent study confirmed that more than 60 percent of caregivers reported that food allergy significantly impacted their home meal preparations and almost half reported that it had an influence on family social activities as well. Children with food allergies also have a higher incidence of being bullied by their peers.
According to the National Center for Chronic Disease Prevention and Health Promotion, about 4-8 percent of children and 2 percent of adults have food allergies. The most common triggers, causing 90 percent of allergic reactions, include egg whites, cow’s milk, peanuts, tree nuts, fish, shellfish, soybeans and wheat. The incidence of food allergy has been increasing with a recent report of an 18 percent increase from 1997 to 2007. However, some experts have noted that it is unclear if this increase is accurate as food allergy is frequently misdiagnosed. This was the situation with Suzie.
Another study analyzed 125 children with atopic dermatitis (eczema), who were on restricted diets for food allergy, diagnosed by a blood test, like Suzie. Of the children with no history of severe food reaction, 89 percent were able to eat the suspect food without a problem. This finding supports the current guidelines that recommend that the best way to accurately make the diagnosis of food allergy is to use a thorough history, physical exam, and appropriate diagnostic test. Allergy skin-prick tests and, when appropriate, oral food challenges that involve gradual ingestion of increasing quantities of the suspicious food while closely monitoring the patient ultimately confirms the diagnosis.
Suzie had eaten all of the suspect foods without a problem prior to the blood test report. In our office, her allergy skin tests were negative to foods, but interestingly she did have positive reactions to inhalants including house dust mite and dog dander. She also had oral food challenges in our office and Suzie was able to tolerate milk, peanuts and wheat proteins without a problem. Therefore, they were all added back into her diet.
Suzie’s situation is typical for a number of children we have been seeing recently who have been struggling with diet limitations because of a misdiagnosis of food allergy. The take-home message is that the most important aspect in the management of food allergy is to have an accurate diagnosis. This often includes more than one test and should be confirmed by an allergy specialist.
Editor’s note: Dr. Stanley Fineman is the Past President of American College of Allergy, Asthma & Immunology and was recognized in Atlanta Magazine’s Top Docs and Best Doctors in Georgia. He is currently an allergist at Atlanta Allergy & Asthma, www.atlantaallergy.com/ 770-953-3331
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