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Separating myths from realities regarding food allergies
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There are a number of misconceptions about food allergy, and primary care physicians can best serve their patients by dispelling those inaccuracies, experts told Healio Primary Care Today.
The most basic misunderstanding is the nature of food allergy symptoms, according to Kanao Otsu, MD, MPH, an allergist and immunologist from National Jewish Health in Denver.
“Some think a food allergy is the stomachache or headache they get after eating certain foods. But these are not an allergy. ‘Some believe that every symptom they experience after eating a specific food is because of a food allergy. That is not always the case. There are intolerances and adverse reactions to foods that are not related to having a food allergy at all. The most common symptoms of a food allergy are: tingling or itching in the mouth; developing hives, itching and swelling of the tongue, lips or face. Other symptoms are asthma like symptoms such as wheezing, chest tightness, nausea, vomiting or diarrhea, after coming into contact with the food,” she said in an interview.
Another allergist discussed a concern regarding food allergies.
“Oftentimes during primary care visits, patients mention allergies to certain foods and medications to the medical professional taking their weight or blood pressure. But the information is not addressed by the PCP,” Tania Elliott, MD, FAAAAI, FACAAI, an allergist at NYU Langone Health in New York City, added.
PCPs are likely to hear more questions about food allergy as the prevalence in U.S. adults is rising, from 5.3% in 2001, to 6.5% in 2010, to 10.8% in 2016. Rising at an even faster rate is the number of patients who self-report a food allergy, but do not actually have one: 9.1% in 2001, increasing to 13% in 2010, and 19.8% in 2016.
“Because living with [food allergy] has nutritional, psychosocial and other consequences that can negatively impact health and quality of life, a proper diagnosis is essential,” Linda Verrill, PhD, of the FDA's Center for Food Safety and Applied Nutrition and colleagues wrote in Allergy Asthma Proceedings.
To clear up some of the myths surrounding food allergy, Healio Primary Care Today consulted several sources and asked Otsu, Elliott to discuss testing and treatment for the condition.
They said the diagnosis process starts by taking a patient’s respiratory, ear/nose/throat and dermatological history with these questions:
- Is there a personal or family history of allergy?
- What are you typically doing for the 6 hours prior to the reaction?
- Are there problems with specific foods? Which foods and what problems?
- How long has this complaint occurred, and what are the symptoms and reactions?
- How do you manage the symptoms and reactions?
- Have you needed urgent care or unscheduled appointments to treat these symptoms and reactions?
- How has the problem affected your quality of life?
In addition, when children claim a food allergy, they or their parents should be asked: Was the child breast-fed? Has the child ever experienced significant weight gain or loss? What is their dietary history?
Elliott and Otsu both told Healio Primary Care Today depending on the answers, a partial diagnosis has already been made.
“With true food allergy, the person has to have a reaction 100% of time he or she encounters the food. If a patient says the reaction only happens some of the time, it is not an allergic reaction,” Otsu said.
Elliott, who is also a spokesperson for the American College of Allergy, Asthma and Immunology, offered other telltale signs the reaction is not a food allergy.
“If a patient reports nonspecific symptoms such as bloating, fatigue, weight gain, or a headache associated with regular ingestion of a food, that is highly suggestive of intolerance over allergy, Elliott added.
If food allergy is not ruled out at during the verbal patient history, patients should undergo either a blood test to look for immunoglobin E antibodies or a skin test, where a drop of solution containing the suspected food allergen is entered into the patient’s forearm or back to gauge reaction, Otsu said. The Food Allergy Resource & Education website indicates that as many as 60% of these tests come back as false positive.
Elliott provided pointers that PCPs should do after the blood or skin test.
“You need to ask the patient again: ‘What happens when you eat the suspect food?’ If the answer is: ‘Nothing, I eat it all of the time,’ it is not an allergy. If the patient’s answer is, ‘I try to avoid them,’ ask the patient about the triggers, symptoms and reactions,” she said.
The next step is a food challenge, according to Otsu. Contrary to some beliefs, this test is the only definitive way to diagnose food allergy, she said.
A food challenge consists of the patient avoiding the questionable food for about 2 to 4 weeks and then slowly being reintroduced to it with as small a portion of the food as possible and only while the PCP is present.
“Though this might sound like a simple procedure, patients should never be told to conduct one at home,” Otsu said.
She added that allergies run the gamut of the food pyramid and are not only diagnosed in kids.
“Contrary to some people’s beliefs, just about any food, in any amount, can cause a food allergy, and no one is ever too old to develop a food allergy,” Otsu said. “All potential food allergy concerns should be taken seriously until all tests definitively prove otherwise.”
Elliott added that after a food allergy has been diagnosed, the PCP must move onto addressing the seriousness of the condition.
“Not everyone realizes food allergy can cause life-threatening reactions or knows how to treat them. Sometimes my patients tell me they do not have an EpiPen. Or they tell me they took an antihistamine and the symptoms went away,” she said.
“This is the scariest thing for me to hear, because antihistamines will not stop an allergic reaction from progressing,” Elliott continued. “I tell my patients some reactions will be severe, and some will not. I also tell them the only thing that can definitively save you from death from food allergy reaction is an EpiPen.”
Research offers additional insights into other steps the PCP should take after diagnosis.
“Ensuring that patients are sent home with a concise anaphylaxis action plan and the proper medication can help the child feel more at ease at school. Educating families on using self-regulation for chronic disease strategies, conducting confirmatory oral food challenges, and keeping them informed about how to manage their child’s food allergy may be effective strategies to help increase the quality of life for patients and their caregivers,” Madeline Walkner, BS, of the Ann & Robert H. Lurie Children’s Hospital in Chicago, and colleagues wrote in Pediatric Clinics of North America.
Patients and PCPs with other potential misconceptions about food allergy can consult the American College of Allergy, Asthma and Immunology and similar medical societies’ websites. – by Janel Miller
References:
ACAAI.org. “Food allergy.” https://acaai.org/allergies/types/food-allergy. Accessed Feb. 14, 2019.
Food Allergy Research & Education. “Blood test.” https://www.foodallergy.org/life-with-food-allergies/food-allergy-101/diagnosis-testing/blood-tests. Accessed Jan. 9, 2019.
Food Allergy Research & Education. “Food allergy myths and misconceptions.” https://www.foodallergy.org/life-with-food-allergies/food-allergy-101/food-allergy-myths-and-misconceptions. Accessed Jan. 9, 2019.
Food Allergy Research & Education. “Food elimination diet.” https://www.foodallergy.org/life-with-food-allergies/food-allergy-101/diagnosis-testing/food-elimination-diet. Accessed Jan. 18, 2019.
Food Allergy Research & Education. “Oral food challenges.” https://www.foodallergy.org/life-with-food-allergies/food-allergy-101/diagnosis-testing/oral-food-challenge. Accessed Jan. 18, 2019.
Food Allergy Research & Education. “Skin prick tests.” https://www.foodallergy.org/life-with-food-allergies/food-allergy-101/diagnosis-testing/skin-prick-tests. Accessed January 2019.
Gupta RS, et al. JAMA Network Open. 2019;doi:10.1001/jamanetworkopen.2018.5630.
Royal College of Paediatrics and Health. “RCPCH Allergy Care Pathways Project: Taking an allergy-focused clinical history.” Accessed January 2019.
Verrill L, et al. Allergy Asthma Proc. 2015;doi:10.2500/aap.2015.36.3895.
Walkner M, et al. Pediatr Clin North Am. 2015;doi:10.1016/j.pcl.2015.07.003.
Disclosures: Elliott reports no relevant financial disclosures. Healio Primary Care Today was unable to obtain Otsu's relevant financial disclosures prior to publication.