Insensitivity, hives, anaphylaxis, allergy—whether we are becoming more quick to recognize allergies or if the prevalence of allergies is actually increasing, one thing is sure—MANY people have allergic reactions to foods and medications. I find that many patients are confused about these terms, so this week’s topic will discuss allergic reactions to food and medications.
- Sensitivity: this word can be used very broadly, but usually denotes a simple intolerance of a substance, such as having breakouts, headaches, or mild stomach pains.
- Allergic Reaction: There are many subtypes of allergic reactions, but the most well-known by patients are “Type One”, caused by a specific immune cell: IgE. Interestingly, the only clearly delineated role of IgE in our bodies is to protect us against parasitic infections—so it’s actually hypothesized that in developed countries where our bodies are not challenged with parasites every day, its benefit may actually be outweighed by the allergic consequences. (caveat—I do not advise obtaining parasites to treat your allergies!) Type I reactions have multiple manifestations in different patients, but can be caused by medications, food, bee stings, and latex. In these reactions, exposing your body to something to which you are allergic causes inflammatory cells to release many chemicals, including histamine and nitric oxide. Two of the major categories include:
- Hives (urticaria): those welts that itch and can be all over your body or just in a specific area. Urticaria is said to affect up to 20% of people at some point in their lifespan.
- Anaphylaxis: the most severe form, and occurs in some patients in whom an allergic reaction doesn’t just cause hives, but actually causes swelling of their throat and breathing passages, severe rash, vomiting, dangerously low blood pressure, and even death.
FOOD ALLERGIES: Earlier this year, the American Academy of Allergy, Asthma, and Immunology released their new food allergy guidelines. Interestingly, they noted that children often grow out of allergies to milk, eggs, wheat, and soy. Allergies that often last for life are peanuts and shellfish. When these allergies develop as an adult, they tend to be more persistent. The best way to test for these allergies is to perform skin tests, blood tests for some patients, an “blinded oral food challenge”, or an elimination diet.
MEDICATION ALLERGIES: Medication allergies follow many of the same patterns as food allergies, with the same breakdown into Hives/urticaria as well as anaphylaxis, and the same treatments are followed. Some of the most common allergies include to drugs such as penicillins. If you or your child has had an actual allergy like the ones listed above, it’s important to note that, and then it’s also important to know what antibiotics that have received that were not a problem. This is especially important because some medications cross-react with penicillins, but so we need to know what they can and cannot tolerate.
PREVENTION: The guidelines that I mentioned above noted that there seems to be little data to support food elimination strategies during pregnancy or breast-feeding in the prevention of allergies (Note, some foods and beverages should be avoided for other reasons in pregnancy—I’m only referring to foods that could cause an allergy in this case!). They do recommend breast-feeding for the first 4-6 months of life, as that can reduce later allergies. TheAmericanAcademyof Pediatrics in 2010 stated that there was no data to support the avoidance of any type of food in an attempt to prevent a child from developing a food allergy if they had never had a reaction.
Once someone has developed an allergy, the best prevention is through avoidance diets (nut-free, gluten free), although –especially in children—it’s very important to make sure that you are getting adequate nutrients if you have to follow one of these.
- Mildest symptoms (to treat itching, rash/hives and minor/moderate swelling) are treated with anti-histamines.
- Diphenyhydramine (Benadryl). Since this makes you sleepy, I advise my patients to take a non-drowsy alternative, such as Zyrtec or Claritin. One other trick is to add Pepcid, which can indirectly help. It may be a small benefit, but if you’re skin is itching and you have to be at work, many people feel that it’s worth it!
- Steroids, such as Prednisone, may be considered in some patients with severe symptoms, but only in discussion with your physician and require a prescription.
- Epinephrine: this is the gold-standard treatment for anaphylaxis (not for the less severe types!). It is given through an intra-muscular injection. For patients with a known anaphylactic reaction, I always make sure that they have multiple Epi pens—they should have enough pens such that one is always within reach, but not too many that they cant keep track of them and allow the medication to expire!
CAUTION: When Identification of Medication Allergies can Become Detrimental:
One concerning situation that I have seen recently is increasingly more patients coming in with LONG lists of medications to which they are “allergic”, when in fact they either don’t know their reaction, or they actually just had a mild sensitivity. In situations in which a patient is extremely ill and needs that specific medication or a close relative of it, or they are comatose, it truly leaves the physician’s hands tied, and often forces us to choose a sub-optimal medication. It is therefore crucial, and something about which I educate all of my patients, that they are vigilant to keep ONLY those medications to which they truly are allergic on the “allergies” list. Keep a separate list on your person for medications that did not agree with you—that’s important too. Accurate knowledge of your health is powerful and the greatest way that you can help your physician to provide you with the best, most life-saving care.
Good luck, be healthy, and live your best this week!