Frequently Asked Allergy Questions

 These FAQs were put together by the staff working in allergy. I asked our allergy nurses what questions they encounter- they are included here. Dr. Vitalpur and I also added a few. These were written in the early part of 2011 but never used by those who requested them. I did not want the work to go to waste.



What allergic conditions can be tested?

 Allergic conditions include; anaphylactic shock, asthma, nasal allergy, hives, swelling, and eczema. Allergy can be responsible for a number of gastro-intestinal conditions. These conditions can be triggered by pollens, spores, animal dander, insect parts, food, drugs, or insect stings.

We can skin prick test for foods and environmental allergens. We have testing materials to determine Penicillin allergy only, we would need warning to make up materials for other pharmacologic agents, but this tends to be unreliable. Concerns about other medications would require desensitization or a challenge procedure which is scheduled at another time. We can test for reactions to local anesthetics. We offer insect sting testing for anaphylactic reactions to stings. Patch testing is limited to foods to determine a possible delayed reaction in conditions such as Eosiniphilic Esophagitis.

 How is allergy skin testing performed?

       Allergy skin testing is done using a small piece of plastic that has a few sharp points. This apparatus is sitting in a well of the allergen extract. The child’s back is cleaned with alcohol. A few skin marks are made to identify the areas where the tests are placed. The device is then gently brought onto the skin and a slight prick to the skin is made. A timer is set for 15 minutes. Once 15 minutes have passed, the physician reads all of the tests. An answer regarding allergy is provided once these tests are read. One ‘prick’ is done for each item tested. We always need to do a positive and a negative control to be sure that we have valid results. The total number of tests that are done depends on the story- sometimes we do need to test, sometimes we are preparing the child to go on allergy shots and many tests may be needed.

 I have heard about blood tests for allergy, how do they compare with skin tests?        

 Blood tests are another way to evaluate for allergy. This was once upon a time called RAST. That term is old and refers to a technology that has not been used for years. Currently the blood test is referred to as specific IgE. These blood tests for allergy are not better than the skin test. There is a tendency for them to over-call inhalant allergy. They are offered as panels which may include many items that are not relevant to the child’s history. The results can be confusing and they are expensive. We utilize the specific IgE test for individual food allergens as we follow a child’s natural history of a food allergy. The specific IgE to a food that was diagnosed by history and by skin prick tests can be used to suggest a risk of having a reaction. These tests help guide us in deciding who could undergo a food challenge.   

 How helpful are food IgG tests?

 The position of the American College of Allergy, Asthma, and Immunology is that food-specific IgG studies, along with provocation-neutralization assays and hair analysis, are unproven or experimental in diagnosing allergies.  A recent study published in The Lancet concluded that diets using results of food IgG testing to manage ADHD should be discouraged.

 Can allergies be treated by drops?

 The short answer is that allergy cannot be treated by oral drops at this time. I would also add not in this country.

This form of therapy is popular in Europe and we are seeing studies about the effects from this form of treatment. However there does not seem to be a consistency in how it is done, what is used, how it is used, how much is used, when it is used, for which allergens and for how long. This has been a topic for an evidence-based medicine review which pointed out these deficits in the published studies on this topic.

Now this form of therapy is being used in research on some forms of food allergy. This is research and it is not at this time a recommended treatment.

 Can allergy testing help with behavioral issues, ADHD, or autism, or reactions to food additives?

 The American College of Allergy, Asthma and Immunology states, “Attention-deficit disorder with or without hyperactivity, autism, and other behavior problems have never been convincingly demonstrated to be related to ingestion of food.”  The types of allergy testing that we offer assist with IgE-mediated food allergic reactions, i.e., those that occur within two hours of consuming a food and are associated with hives, wheezing, swelling, or other severe reactions.  We do not offer any allergy testing with regard to behavioral issues. Regarding food additives, immediate allergic reactions are rare, but can occur.  Unfortunately, there are no validated allergy tests for food additives, dyes, or preservatives.

  How can allergy testing help with asthma management?

 Studies have shown that in children, as many as 70-80% of patients with asthma will have some type of allergic sensitization.  Identification of those sensitivities can help guide treatment for asthma.  Treating the nasal and sinus issues can also improve asthma symptoms.  The National Heart, Lung, and Blood Institute also state that the impact of allergies on asthma is greater in children than in adults.  Allergy treatment can involve environmental controls, medication, and, possibly, immunotherapy (allergy injections). An allergist is specially trained to help manage allergy and asthma issues.

 Will a person have anaphylaxis to allergy testing? Is it systemic?

 An anaphylactic reaction is not likely to happen. The testing is topical and the applicator only scratches the skin surface.

 Tell me about ‘allergy shots’- how long and for what allergens- specifically the food issue

 Allergy injections are given for environmental allergens.  When injections are given regularly it reduces the risk of an adverse reaction. During the initial build up, the injection dose is usually increased only when given weekly.

The Riley Allergy clinic does not offer allergy injections for food related allergies.

 Can a person outgrow an allergy, specifically a food allergy?

 Some food allergy can be outgrown and some are life-long. We use the specific IgE level to a particular food to help assess the risk of a reaction. When an IgE level is low enough which would mean that the risk of a reaction is low, we will offer a food challenge in our office. If the patient passes the food challenge the patient is free to eat the food in question. The allergy at this time will be considered out grown.

 Tell me about doing a challenge for food allergy?

 When the specific IgE blood test is at a low enough level, we can offer a graded food challenge in the office. We will schedule your child to arrive in the morning. We give measured doses of the food mixed in a food   brought from home such as pudding, yogurt, or applesauce. Each dose is given every 15 minutes until the child has consumed a full serving. After an observation period and the child has not had a reaction, the child is free to include this food in their diet.  If at any time during the challenge, the child exhibits signs of a reaction, we stop the challenge, treat the reaction, and observe them for a specified time.

 My child keeps getting hives and we need to know what causes them.

 Hives can be very frustrating. Often we cannot determine the cause .Hives may occur acutely due to an infection, but usually hives cannot be connected to a specific incident.  Skin testing does not prove to be very valuable without a consistent story. If hives become chronic, we can evaluate with blood tests (looking at other non-allergy causes) to determine if any underlying condition could be the cause. Often what we can offer is a regime of antihistamines to treat the symptoms.