What You Can Learn From Allergy Testing

What You Can Learn From Allergy Testing

What You Can Learn From Allergy Testing

Avoiding allergens (or at the very least having a reliable antihistamine on hand) has undoubtedly become a top concern for anybody who suffers from allergies, whether they be to foods, pet dander, pollens, or materials such as wool. And if you find yourself sniffling, sneezing, and feeling a little itchy—or worse—every time you come into touch with any of these items, know that you are not alone in your feelings of discomfort.



This is due to the fact that more than 50 million Americans suffer from different kinds of allergies every year. It’s possible that you’re unaware of the fact that your doctor may conduct a number of various tests to assist narrow down the source of your symptoms.

“We can test for food allergies, environmental allergies, and certain medication allergies,” explains Sherry Farzan, MD, an allergy and immunologist at Northwell Health’s Cohen Children’s Medical Center and head of the Asthma Center. 


“We can also screen for asthma and other respiratory problems.” As a supporting guide, allergy testing is performed if there is any suspicion that any of them may be a problem for a person. The history of the patient, Farzan emphasizes, “what they tell us about previous exposures and responses” is the most essential piece of the jigsaw, “and allergy testing is used to assist in substantiating that history.”



The procedure for allergy testing

First and foremost, there are some significant distinctions between the many kinds of allergies that a person may be susceptible to, as well as their possible responses. When it comes to more severe allergies, such as those to foods, medicines, bee stings, and latex, exposure may result in anaphylaxis, which is a potentially life-threatening type of allergic response that can occur. Seasonal allergies, which do not usually result in anaphylactic responses, may produce severe hay fever symptoms, as well as the exacerbation of asthma and eczema symptoms in certain people.



During the course of your medical examination, your doctor will go over everything that you may have come into contact with that might be an allergen in order to determine what caused your allergic response. Your personal notes or journal entries about what you believe caused your allergy symptoms are often one of the most effective weapons in the doctor’s arsenal.



For example, suppose your adolescent went to a restaurant and ordered a wrap with chicken, pesto, and avocado, after which he or she developed hives. “We inquire as to whether or not they have had any of those symptoms since then,” Farzan explains. For example, if someone claims to have eaten bread and chicken in the intervening time period, but is apprehensive about eating avocado and pine nuts, “we would test them for the items they haven’t consumed.”



The majority of allergists utilize both skin and blood testing to determine whether or not a patient is allergic to a particular allergen.

What happens during a skin test. Your allergist will mark regions of the skin with a pen and put a droplet of a solution containing the allergen next to each mark before gently pricking the allergen extract into the skin with a needle, as described above. It takes about 15 minutes for your skin to be examined for redness and a wheal (or hive), which are indications of an allergic reaction. A red, itchy bump will appear if you have a positive response to any of the chemicals administered. The allergist and their team will measure the size of the bump before the markings are washed away to determine the severity of your body’s reaction.



What happens during a blood test. 

As the name implies, these tests assess IgE levels—or antibodies—in your blood, which are produced by your immune system in reaction to certain allergens. They are often performed in conjunction with skin testing, especially in the case of suspected food allergies or a history of anaphylaxis. Skin tests are often replaced with blood testing if someone has recently taken steroids, antihistamines, or certain antidepressants, all of which may interfere with the findings of a skin test. People who have severe asthma, unstable cardiac problems, or skin diseases such as eczema, dermatitis, or psoriasis may also be subjected to blood tests as part of their treatment.



What are false positives and what do they indicate?

While both skin and blood tests may be useful in identifying what a patient may be sensitive to, they can also produce false positives, which means that the test detects an allergic response when there is none. “When it comes to food testing, we may get a lot of false positives,” Farzan explains. “Skin testing offers a higher specificity for environmental allergies than other types of testing.”

In order to avoid this, allergists now advise against doing skin prick tests across the board unless there is a strong suspicion that a specific food or chemical is responsible for the response.



“If you tested 100 individuals off the street for a peanut allergy, both skin and blood tests would come back positive, with the magnitude of the positive test varied,” Farzan explains. “However, it’s likely that those 50 individuals will have no problems eating peanuts.” This is an example of a false positive.” It shows sensitization, which means that your body has been exposed to a peanut allergen and has produced antibodies against peanuts, but it does not necessarily respond when we consume a peanut (as opposed to an allergic reaction). Farzan says that in these situations, the only method to determine if a person is really allergic to peanuts is to provide peanuts to them.



In the case of a toddler who acquired skin lesions after the consumption of a cracker with peanut butter, Farzan recommends that the child be strictly avoided for a period of time, after which the child “would continue to be followed with blood and skin tests as they grew.” In the event of an accidental exposure, the parents would be advised to have an EpiPen on them at all times, and if or when skin and blood tests came back negative, or the welt had grown to a size that we were comfortable with, we would issue a food challenge. 


Food challenges are when a patient consumes a complete serving of their allergen (for example, peanuts) over the course of many hours in their doctor’s office or in a hospital environment. They are most often seen in pediatric patients. There, kids may be carefully watched for a response in order to determine whether or not the allergy has been outgrown.


What you should do to prepare for testing

If you think you may be allergic to a chemical, maintain a journal of what you ate and any reactions you had after eating it (hives, itchy mouth, etc.). As a result, you will be able to provide your allergist with comprehensive information that will assist them in pinpointing the source of your allergy.



Farzan advises against using an antihistamine, such as cold or allergy medicines, five to seven days before the test since they may lead you to get a false negative result. When you schedule your visit, inquire as to if there are any additional medicines you should discontinue. (They will generally emphasize that if you need to take an antihistamine before the test, you should do so and postpone the appointment.) Additionally, you will be advised to refrain from using any lotions or fragrances on the day of your examination.



According to Farzan, “If you are allergic, the skin test can produce red, itchy bumps on your skin,” therefore “we administer a topical steroid to the spot after we have done our reading and offer them an antihistamine if they are experiencing pain from the itching.”

Please bear in mind that pinpointing the cause of your allergic response may take some time and patience, but you and your allergist can work together to determine the culprit and develop a strategy to keep you safe.

Should my food allergies prevent me from eating out or ordering takeout or a meal delivery service?

Food allergies may be life-threatening. Someone who suffers from a life-threatening allergy does not want to put himself in any needless danger. While dining out or ordering takeaway should be avoided if possible, the COVID-19 epidemic has resulted in an exponential increase in takeout orders, which should not deter you from doing so. To ensure that you may safely dine out at any time, it is critical that you communicate your allergy needs properly.


Communication is essential.

Avoiding ordering food online is a simple method to guarantee that your dietary restrictions are appropriately conveyed to the restaurant. Ordering in person or over the phone is the most convenient option for most people. It is also possible that you will want to pick up your order from the restaurant rather than having it delivered so that you can double-check that all of your criteria have been fulfilled.



As Dr. Roshini Mullakary, an allergy and immunology expert at Northwell Health Physician Partners/Westchester Health, advises, “Try speaking to the most senior person in charge, such since the manager, as they are most likely to be aware of the cooking procedure.” Because they are the ones who prepare your meal, “if at all feasible, the ideal person to talk with would be the chef.”



The majority of eateries are prepared to accommodate such demands. No, you are not the only one who has dietary limitations. As the incidence of food allergies and other involuntary dietary modifications continues to increase, restaurants are becoming more used to receiving dietary demands and have procedures in place to deal with limitations.

“The most essential thing is to communicate in a proactive manner,” Dr. Mullakary added. “Make certain that, regardless of how you are purchasing, you are expressing your worries… In the event that you purchase from a website or via an app, be sure to contact the restaurant afterwards to explain your food allergy requirements.”



Don’t be concerned if you’re not sure which eateries will meet your demands. Discovering which establishments are more accommodating to allergy-related demands than others is becoming more popular. AllergyEats is a smartphone application and website that assesses how accommodating a restaurant or shop is to individuals who have food allergies. Some establishments even offer menu choices that are specifically tailored to cater to those with certain sensitivities.

So, what do you think you should order? What’s more essential is to understand what you should avoid.



Cross-contamination is more likely to occur with some foods, especially those that include a large number of ingredients, sauces, or dips. Keep your orders as basic as possible. Also, be sure to speak out for your own interests! If you have a food allergy, there is no need to be ashamed about it, and there is no reason to feel like you are inconveniencing restaurant workers by asking more questions. They are asked these kind of inquiries more often than you would expect.



Doctor Mullakary advises, “You want to make it very obvious to the individual with whom you are conversing that you have a food allergy that may be life-threatening.” You should inform them that you are allergic to the allergen and inquire as to whether they would prepare your dish on a different piece of equipment.”

It is possible that, despite everyone’s best efforts, an allergy will be present in your purchase at the end of the day. In the event that you discover an allergy in your food, stop eating immediately since you may have already swallowed part of the allergen that you were not aware of. If you have any symptoms, consult with your allergist for advice on how to handle the situation. And don’t forget to have your epinephrine auto-injectors with you at all times, particularly while dining out.