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If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.
You’ve gotten away sniffle-free and without sneezes for years. While your friends have complained about itchy eyes and scratchy throats every year, you’ve successfully skated by, season after season, unscathed.
But suddenly, one spring day, you wake up with what seems like a cold, but you can’t quite shake the symptoms. Could it be allergies? At your age? It turns out that, while most allergies develop during childhood, there are several reasons you might notice new symptoms and issues well into adulthood.
We spoke with allergy expert David W. Rosenthal, DO, Ph.D., about adult allergies, including triggers and treatments. Dr. Rosenthal is an attending physician in the Division of Allergy/Immunology at Northwell Health Physician Partners in Great Neck, New York.
What are adult allergies?
According to Dr. Rosenthal, “You can acquire allergies as an adult—even to things that didn’t bother you when you were younger. Most of the time, you acquire allergies to environmental triggers, like dogs and cats, cockroaches, pollen, grasses, trees, and weeds.”
Prescription allergy relief, without the waiting room
Finding the right allergy treatment shouldn’t be a guessing game. Talk with a healthcare provider.
While you’ve probably heard a lot about allergies and seen countless television ads promising relief from symptoms, you may not understand what they are and how they work. An allergy is essentially your body’s way of trying to protect you from an invader. But in trying to keep you safe from harm, your immune system has gone overboard. Whenever your body is acquainted with something new in the environment, you go through sensitization.
Sensitization means your immune system tries to figure out whether the thing you’ve just encountered is a threat to your wellbeing. If it decides that the answer is yes, it deems that substance an allergen and starts producing proteins called antibodies to fight it, called immunoglobulin E or IgE.
The problem is that when your immune system starts producing IgE to fight off the (often harmless) allergens, your body begins experiencing signs and symptoms of an allergic reaction. Allergic reactions look and feel different between people and between allergies. The symptoms can range from mild (sneezing and itching), all the way to life-threatening (anaphylaxis, a medical emergency that involves everything from swelling of the throat and tongue to dangerous blood pressure drops).
People can be allergic to just about anything, including different kinds of foods, insect stings, medications, pet dander, and more. Allergic rhinitis, otherwise known as “hay fever,” is a common type of allergy that affects up to 30% of American children and adults (Akhouri, 2021).
Some common symptoms of allergic rhinitis include sneezing, running nose, itchy eyes, itchy mouth, itchy skin, stuffy nose, and fatigue. Common triggers for allergic rhinitis include grass, tree, and weed pollens, pet dander, dust, mold, cigarette smoke, perfume, and more.
Food allergies affect many people and are commonly triggered by things like milk, eggs, fish/shellfish, peanuts, tree nuts, soy, and wheat.
Why do adults develop allergies?
According to Dr. Rosenthal:
“People develop allergies at different ages, often occurring in early childhood, adolescence, and as you get into your 40s. You can also have certain allergies that get worse or better over time. It’s unclear why that happens, just like we really don’t know why one person will have allergies and another person won’t. People have allergies because of a gene-by-gene, by-environment interaction. That means there are certain genes we inherit that confer susceptibility to having allergies, but exposure to allergens in the environment also determines if you’re allergic.”
So there isn’t one single reason adults develop allergies. Experts know that our genes play a significant role. Research has shown that allergic diseases develop from an interaction between DNA and environmental factors. Twin studies have demonstrated that genes contribute more than 50% to the development of allergic conditions (Jenerowicz, 2012). And research has shown that a child with a parent or sibling with a peanut allergy is seven times more likely to develop a peanut allergy than someone without that family connection (du Toit, 2016).
In the case of hay fever, several new environmental triggers could set off symptoms. For example, you may experience new allergic symptoms if you move to a new location as an adult and are exposed to different types of pollen or grass. If you’ve never owned a pet and decide to get one as an adult, you may suddenly discover that you’re allergic to pet dander. Other environmental triggers like certain perfumes, cigarette smoke, air pollution, and more can all trigger allergies you may not have known you have if you’ve never spent much time around them.
Food allergies often occur in children, and most people outgrow food allergies with age. For some people, however, food allergies can last a lifetime. According to recent research, a growing number of adults are actually developing food allergies later in life (Gupta, 2019)
Types of adult allergies
There are two primary types of adult allergies—allergic rhinitis and food allergies.
Getting allergic rhinitis or seasonal allergies as an adult is fairly common, especially when people move to a new area, according to Dr. Rosenthal. “What typically happens is that the first couple of seasons you are in a location, your allergies aren’t that bad. However, after you’ve spent two or three seasons there, you tend to get more allergies. A simple way to think about it is like a bucket: You start to fill a bucket with water, and it takes time for the bucket to overfill. This is called sensitization—your body has to be sensitized to those allergens before you start developing symptoms.”
Food allergies are much less common to acquire as an adult. It’s much more typical to develop them in childhood and maintain them. Certain food allergies, like peanut allergies, don’t disappear easily. But it’s pretty rare for someone who tolerated peanuts to suddenly develop a severe peanut allergy as an adult.
A recent study asked over 40,000 American adults about their food allergies. It noted that almost 11% were food allergic at the time of the survey. Interestingly, nearly half of those who reported food allergies had at least one food allergy that did not start until adulthood (Gupta, 2019).
The most common food allergies that start in adulthood are allergies to shellfish, tree nuts, and finfish. However, studies show that you can develop adult-onset food allergies to all major food allergen groups (Kamdar, 2015).
Many people think that any reaction you have to food is an allergy. That’s not entirely accurate. There are many different sorts of reactions you can have. Some people have a mild stomach upset due to an intolerance to lactose or gluten. While that could be called a sensitivity, that’s not an allergy by definition because it involves different parts of the immune system.
Adult allergy symptoms
Common symptoms of adult seasonal allergies may mimic the “common cold” and include (Akhouri, 2021):
- Sneezing or a runny nose
- Postnasal drip or frequent throat clearing
- Nasal, ear, or sinus congestion
- Watery or itchy eyes
- Itchy throat
- Dark circles under the eyes (allergic shiners)
Seasonal allergies: how to prevent, spot, and treat symptoms
Adult food allergy symptoms can be severe and may include (ACAAI, n.d.):
- Trouble breathing
- Tight/hoarse throat
- Swelling of the tongue
- Vomiting/stomach cramps
Seek medical attention immediately if you experience severe symptoms that cause swelling or affect your ability to breathe.
Testing for adult allergies
If you think you have an allergy, it’s best to see a professional for a definitive diagnosis. A healthcare provider or allergist may perform some tests to confirm your allergy and help you figure out a plan to prevent and treat symptoms.
Your healthcare provider may be able to diagnose your allergies based on symptoms alone. If you have typical seasonal allergy symptoms like sneezing or a runny nose at certain times of the year, that may be enough information. In some cases, though, healthcare providers order other diagnostic tests, like a skin test, to help confirm which allergen is causing the reaction. Allergists and other providers may also recommend blood tests or different kinds of lab work to confirm specific allergies.
Treating adult allergies
According to Dr. Rosenthal, there are three main ways to treat allergies.
The first way is to avoid the allergen—this can prevent your allergic reactions from starting. Avoidance means trying your best to avoid your triggers as often as possible. That might involve staying indoors during the daytime if pollen sets off your symptoms or completely sidestepping certain foods.
The second step is treating your symptoms with medications. If your symptoms are mild and pretty standard, you may be able to treat them with over-the-counter medicine like an antihistamine. Many antihistamines are available over-the-counter, but if your symptoms are severe, your healthcare provider may prescribe something stronger. Multiple long-acting antihistamines are typically very effective at treating the symptoms and don’t make you tired (Akhouri, 2021).
Treating seasonal allergy symptoms: medications that help
The third option is to see an allergist for allergy shots (also called allergen desensitization). You typically stay on that treatment for three to five years. If your symptoms aren’t being controlled with medications, seeing an allergist for allergy testing and allergy shots is the next step. Oral allergy drops are a newer form of allergen desensitization that people can try for certain allergens (Nurmatov, 2017).
If your allergy is life-threatening, you may need to carry around a special medication called epinephrine (EpiPen). If you experience anaphylaxis, immediately injecting a dose of epinephrine can save your life.
- Akhouri S, House SA. (2021) Allergic rhinitis. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK538186/
American College of Allergy, Asthma, and Immunology (ACAAI). (n.d.). Food allergy. Retrieved from https://acaai.org/allergies/types/food-allergy
Centers for Disease Control and Prevention (CDC). (2021, Mar). Allergies and hay fever. Retrieved on June 3, 2021 from https://www.cdc.gov/nchs/fastats/allergies.htm
du Toit, G., Tsakok, T., Lack, S., & Lack, G. (2016). Prevention of food allergy. The Journal of Allergy and Clinical Immunology, 137(4), 998–1010. doi: 10.1016/j.jaci.2016.02.005. Retrieved from https://pubmed.ncbi.nlm.nih.gov/27059727/
Gupta RS, Warren CM, Smith BM, et al. (2019). Prevalence and severity of food allergies among US adults. JAMA Network Open, 2(1):e185630. Doi: 10.1001/jamanetworkopen.2018.5630. Retrieved from https://pubmed.ncbi.nlm.nih.gov/30646188/
Jenerowicz, D., Silny, W., Dańczak-Pazdrowska, A., Polańska, A., Osmola-Mańkowska, A., & Olek-Hrab, K. (2012). Environmental factors and allergic diseases. Annals of Agricultural and Environmental Medicine : AAEM, 19(3), 475–481. Retrieved from https://pubmed.ncbi.nlm.nih.gov/23020042/
Kamdar, T. A., Peterson, S., Lau, C. H., Saltoun, C. A., Gupta, R. S., & Bryce, P. J. (2015). Prevalence and characteristics of adult-onset food allergy. The Journal of Allergy and Clinical Immunology: In practice, 3(1), 114–5.e1. doi: 10.1016/j.jaip.2014.07.007. Retrieved from https://pubmed.ncbi.nlm.nih.gov/25577631/
Nurmatov, U., Dhami, S., Arasi, S., Roberts, G., Pfaar, O., Muraro, A., et al. (2017). Allergen immunotherapy for allergic rhinoconjunctivitis: a systematic overview of systematic reviews. Clinical and Translational Allergy, 7, 24. doi: 10.1186/s13601-017-0159-6. Retrieved from https://pubmed.ncbi.nlm.nih.gov/28794855/