Wide Testing of Asthma Kids for Peanut Allergy Is Wrong, Say Allergists
A recent study suggesting that children with asthma should be more routinely tested for peanut allergy is being criticized by both major American allergist societies.
Both the ACAAI and the AAAAI are telling the public and physicians that indiscriminate testing for peanut allergy can lead to inaccurate diagnosis (since there are many false positives), and they remind of the importance of the patient’s symptom history in a proper food allergy diagnosis.
Further, they say that without that history of specific symptoms to peanut, health-care resources could be squandered and patients could be unnecessarily directed to follow a strict peanut avoidance diet.
Following is the American College of Allergy, Asthma and Immunology (ACAAI) news release on the topic:
A new study promoted during the American Thoracic Society’s annual meeting has received considerable media attention on the topic of children with asthma being prone to peanut sensitization. Sensitization means having a positive peanut test but no clear history of peanut allergy. The study authors suggest that children who have poorly controlled asthma may be more likely to have a peanut sensitization, and that parents should consider having kids with asthma tested for possible peanut allergy.
According to allergist Matthew Greenhawt, MD, FACAAI, “Such testing could potentially lead to misdiagnosis, and represents an unnecessary and unjustified use of resources. While many of the children in the study are peanut sensitive on testing, it raises a question of relevance as to why testing was performed. There is no evidence that diagnosing peanut sensitization better controls chronic asthma. Chronic asthma is not a manifestation of peanut sensitization or allergy. There is no practical value to testing in this situation because these children are not showing any signs of possible peanut allergy.”
Dr. Greenhawt is an assistant professor in the Division of Allergy and Clinical Immunology at the University of Michigan and member of U-M’s Child Health Evaluation and Research and Evaluation Unit in the Department of Pediatrics. His commentary is on behalf of the American College of Allergy, Asthma, and Immunology (ACAAI).
Dr. Greenhawt offered additional points regarding this study and the use of food allergy testing in patients with asthma, so that these study findings are not misinterpreted:
• A food allergy results in specific, acute symptoms (e.g., hives, wheezing, cough, vomiting, etc.), developing within approximately 2 hours of ingestion of a suspected allergen. Without such history, testing is not indicated.
• Chronic, poorly controlled asthma is not an indication of a “hidden” food allergy. Food allergen testing was not indicated in any of these patients.
• Positive allergy blood tests (or skin tests) alone are insufficient to make a diagnosis of food allergy. Many more individuals test positive than will have actual food allergy. Testing for the presence of sensitization to a food is of no value, and cannot be interpreted when positive if the patient does not develop symptoms after eating that particular food.
• While approximately 1/3 of food allergic children develop asthma, and asthma in a food allergic child is a risk factor for more severe reactions, these risks are not associated with the asthmatic child under poor control, without a presumption of a known food allergy. Existing food allergy guidelines do not indicate testing in this situation. However, such children may benefit from inhalant allergen testing to better their asthma control.
Peanut allergy affects approximately 1-1.5% of people in the U.S., and can be associated with severe reactions, which require emergency treatment with epinephrine. If symptoms develop within 2 hours after eating peanuts, an individual should be referred to a board certified allergist/immunologist for further assessment and possible testing.