Frequently Asked Questions

        airborne allergies

Why do some people have allergies and others do not?

Allergies start with the production of IgE (the allergic antibody) against airborne proteins such as mold spores, pollens, and pet dander. The ability to produce IgE is inherited from our parents and is revealed in environments that have significant levels of allergens (like Austin!). People that possess both the ability to react to things in the environment AND live in an environment where there are particles that cause allergies will likely exhibit allergies.

What causes allergy symptoms?

IgE made against a particular allergen is attached to specialized cells called mast cells. When IgE encounters the specific allergen, it causes a change inside the mast cell which results in the release of many substances, particularly histamine. Histamine binds to histamine receptors and causes symptoms. The location where the reaction is taking place determines the symptoms. In the eyes, histamine release causes itching and watering. In the nose, it causes itching, sneezing, congestion, and drainage production. In the throat it causes itching.

Why are my allergies present all the time but get worse during certain times of the year?

IgE can be made agains seasonal pollens such as trees, grasses, and weeds as well as year-round allergens such as molds, dust mites, and pet dander. Testing can reveal which of these are significant and how best to treat the symptoms they cause.

        asthma

I’ve heard that asthma is often treated with steroids; aren’t these bad to take?

Many inflammatory conditions like asthma are often treated with corticosteroids (often referred to as cortisone); steroids that are abused by some athletes are androgenic steroids. Both of these types of compounds can cause significant side effects if abused. However, in the treatment of allergies and asthma, corticosteroids are primarily used topically, that is, they are put directly where they are needed using an inhaler or a nasal spray. When used locally, cortisone-type steroids have few side effects and can keep inflammation (and therefore asthma and allergy problems) under control.

My asthma doesn’t seem to be getting better; what should I do?

Asthma has many potential triggers; some of these include allergies, respiratory infections, weather changes, exercise, cold temperatures, irritants, and even acid reflux. If your asthma is not improving, try to identify where and how your asthma gets worse. You may also want to consult with your doctor, perhaps your medicines may need to be altered or you may need an evaluation for allergies, an infection, or reflux.

When should I worry about an asthma flare-up?

Asthma is a chronic condition that is characterized by inflammation in the airways which in turn causes the muscles around the airways to constrict, resulting in narrowing. Symptoms during a mild asthma attack include mild breathlessness with walking or exercise and intermittent wheezing; with a more moderate flare-up, you may have trouble finishing your sentences without taking a breath and you may experience more nighttime awakenings; with severe exacerbations, you might experience severe shortness-of-breath, even at rest, along with feeling anxious and a need to use your medicines continuously. Severe flare-ups can get worse and become life-threatening, causing confusion, fatigue, and areas on the face to turn blue from the lack of oxygen. Mild and moderate flare-ups can often be treated in our office, but severe asthma attacks are best treated right away in an emergency room. Using your medicines as prescribed and monitoring your asthma with a peak-flow meter can help avert a severe flare-up.

        Food allergies

How do I know if I have a true food allergy or some other kind of food reaction?

Food allergies, like airborne allergies, also involve production of IgE, but against food proteins rather than airborne particles. A food allergic reaction follows the same sequence too, ending with release of histamine which causes symptoms involving the gastrointestinal tract as well as the skin and respiratory tract. Other food reactions, such as gluten sensitivity or lactose intolerance do not involve production of IgE and therefore are not true allergic reactions. The symptoms seen with these other food reactions can be similar to those seen with true food allergies; a thorough evaluation by an allergist can help determine which is causing the problem.

Can testing screen for food allergies?

While testing can uncover the presence of IgE against a particular food, these tests are also often positive to other foods that do not seem to cause clinical symptoms. In other words, false positive tests occur regularly and often confuse or complicate the evaluation. Therefore, testing for foods is primarily recommended for confirming suspicion against a particular food, one in which the history and symptoms suggest a possible allergy. Screening using a large panel of foods is not recommended.

        drug allergies

I once had a rash when I took penicillin; does this mean I’m allergic to it?

A drug rash sometimes occurs for no apparent reason; it may be related to sun exposure or sensitivity to components of the medicine or can be “idiosyncratic”, an unpredictable and unusual effect of the medicine. These reactions are rarely life-threatening and the rash usually disappears upon discontinuation of the drug. True drug allergies occur with the production of IgE; upon subsequent exposure to the drug, an allergic reaction ensues, ending in release of histamine which can manifest as a rash but sometimes causes other symptoms, including wheezing, swelling of the lips, face, and tongue, and anaphylaxis. The best way to determine if a true penicillin allergy exists is to skin test; a negative result suggests that a severe allergic reaction is unlikely.

I seem to have reactions to multiple medicines; can I be tested to determine allergy to all of them?

True allergic reactions to multiple drugs are unusual and it is likely that patients that experience problems with many medicines may actually be suffering side effects or other known drug reactions. If the history suggests an immediate severe allergic response to a medication, testing may be helpful. Unfortunately, standardized skin testing is currently only available for determining penicillin allergy. Testing with medicines other than penicillin is only helpful if the reaction is positive; a negative skin test does not rule out the absence of allergy and cannot guarantee that the drug is safe to take.