How to Identify Allergies

Having an allergic reaction can be scary, especially if you don't know what's causing it. We're here to answer some of your most commonly-asked questions about allergies, including what the symptoms are and what might be causing them. To be 100% sure what's going on, though, make an appointment with an allergist for allergy testing. However, if you're having symptoms of a severe allergic reaction, like you're having trouble breathing, get emergency medical help as soon as possible.

Question 1 of 10:

What are the symptoms of an allergic reaction?

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    Allergies can present with a lot of different symptoms. This mostly depends on what type of allergic reaction you're having, although similar allergies can present differently for different people. There are a few common, symptoms, though. These might include:[1]
    • An itchy or tingling feeling in your mouth
    • Itchy, red, or watery eyes[2]
    • Sneezing or an itchy, runny, or stuffy nose
    • Wheezing, trouble breathing, coughing, or tightness in your chest
    • Itchy skin, raised welts (called hives), or eczema
    • Swelling in your lips, tongue, face, eyes, or throat
    • Stomach pain, nausea, vomiting, or diarrhea
  2. 2
    Get emergency help if you have symptoms of a severe allergic reaction. Sometimes, an allergy can lead to a severe reaction called anaphylaxis. If this happens, you need to get emergency medical care right away, or it could lead to coma or even death. If you've already been prescribed an epinephrine injection, give it to yourself as quickly as possible, but still get to the emergency room in case the symptoms return.[3] Symptoms of anaphylaxis include:[4]
    • A swollen throat or constriction of your airways
    • The feeling of a lump in your throat
    • Shock
    • Sudden drastic drop in blood pressure
    • Rapid pulse
    • Dizziness or fainting
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Question 2 of 10:

How do you know if you have allergies or a cold?

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    You can usually tell by checking your mucus, cough, and temperature. Ok, this doesn't sound like much fun, that's true. However, these things can give you some big clues as to whether you're experiencing allergies or if you might have a cold or another illness. Specifically, check these things:[5]
    • The color of your mucus: If you have allergies, it should stay clear. If you have a cold, it will get thicker, cloudy, and yellow.[6]
    • Type of cough: If you have a nagging, dry cough, chances are, it's just allergies. On the other hand, if you're coughing up mucus, it's likely a cold, although it could also be a virus like the flu or COVID-19.
    • Sore throat: If you're sick with something like a cold or the flu, you'll often get a sore throat, but that's uncommon with allergies.
    • Fever: Severe allergies can sometimes lead to a fever, but it's pretty rare, and you'll likely have other severe allergy symptoms. Fever is much more common with illnesses like a cold or the flu.
Question 3 of 10:

How do you know what you're allergic to?

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    Track your symptoms at home to narrow down your triggers. Every time you experience allergy symptoms, write them down in a notebook or an app on your phone. Note anything you ate or drank, whether you touched any animals, any lotions, soaps, or cosmetics you used, and anything else you can think of that might be relevant. You might even write down what you were wearing—you could be allergic to a certain fabric or laundry detergent.[7]
    • In addition, write down where you were—like whether you were indoors or outdoors.
    • Try to think back for at least a couple of hours before your symptoms occurred. Allergies symptoms usually show up pretty quickly after exposure to your allergen, but they can sometimes take a while to develop.[8]
  2. 2
    See an allergist for testing to know for sure. Although it's fine to discuss your allergy concerns with your primary care provider, it's best to see an allergist for further testing and treatment. At your first appointment, go over your allergy diary with your allergist. They'll also likely talk to you about your family history, and they may do a physical exam.[9]
    • Your allergist will likely recommend testing to determine exactly what's triggering your allergies. A skin prick test is the most common type of allergy test, although they may suggest other tests, as well.
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Question 4 of 10:

What does an allergy test consist of?

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    Skin prick tests are the most common type of allergy test. During this test, a drop of an allergen will be placed on your skin (usually your arm or back), then the allergist will prick your skin gently. They'll usually test several different substances at once. If the location of the prick turns red, you're likely allergic to that substance. This can be a little uncomfortable, but don't worry—it's not painful.[10]
    • If the results of your skin prick test aren't clear, the allergist might do a second test where the allergens are injected under the first few layers of your skin. This is called an intradermal test.[11]
    • They might also draw blood for a lab test if a skin test isn't a good option, like if you have very sensitive skin, you've had a severe allergic reaction in the past, or you take a medication that would affect the test results.[12]
Question 5 of 10:

What are the most common types of allergies?

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    There are four major types of allergies. Typically, people are allergic to something in their environment, food, insect stings, or medications. You may be allergic to one or more items within these categories, as well.[13]
    • Environmental allergies can include seasonal allergies to pollen, perennial allergies to things like mold and pet dander, and contact allergies that lead to skin irritation.[14]
    • Food allergies can occur when you eat a certain food, although if they're severe, they might be triggered when you simply touch or breathe in that item.[15]
    • Insect allergies typically only occur when you are bitten or stung by the insect you're allergic to.[16]
    • Medication allergies can occur with both prescription and over-the-counter drugs, but they are not the same as side effects from taking medication.[17]
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Question 6 of 10:

What is allergic rhinitis?

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    Allergic rhinitis is the sneezing, sniffling type of allergies. If you have allergic rhinitis, it might only show up during certain seasons, although it can also occur year-round, depending on your trigger. Typical symptoms include sneezing, a runny or stuffy nose, and itchy, watery, or swollen eyes.[18]
    • If your allergies tend to occur in the spring or fall, you likely have seasonal allergies, or hay fever. This is triggered by pollen in the air.
    • If your allergies last all year, you might be allergic to something like animal dander, dust mites, mold, or debris left by cockroaches.[19]
Question 7 of 10:

What are contact allergies?

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    Contact allergies are skin-related. If your skin is itchy, red, or flaky, there's a chance that something you're touching is causing an allergic reaction. Some people are sensitive to the chemicals in laundry detergent and fabric softener, so if you've recently changed brands (or your favorite brand has changed their formula), that's a good place to start. Other skin-related allergens might include:[20]
    • Cosmetics, soaps, or lotions
    • Certain fabrics or dyes
    • Latex or rubber
    • Topical medications
    • Irritants like poison oak or sumac
    • Nickel or other metals
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Question 8 of 10:

How can you tell if you have a food allergy?

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    Your symptoms will appear shortly after you eat your trigger food. You might have tingling in your mouth; swelling of your lips, tongue, face, or throat; hives; or an anaphylactic reaction after you eat. Since allergies can be triggered by a hidden ingredient in your food, it's important to see an allergist to determine exactly what you need to avoid. Common foods that trigger allergies include:[21]
    • Shellfish (shrimp, lobster, crab)
    • Fish
    • Peanuts or tree nuts (pecans, walnuts)
    • Cow's milk
    • Eggs
    • Soy
    • Wheat
    • Certain raw foods
  2. 2
    Try an elimination diet if your allergist suspects food allergies. This involves cutting any foods completely out of your diet that you might be allergic to for about 1-2 weeks. Then, you'll introduce them back in one at a time, waiting a few days each time to see if you have any reaction to them.[22]
    • This won't always give you precise results—an elimination diet can't tell you if you're sensitive to a food as opposed to being truly allergic to it, for instance.[23]
    • Only do an elimination diet under the guidance of an allergist. If you've ever had a severe food reaction, it's probably not safe to do an elimination diet at all.
    • Your allergist might also recommend an oral food challenge, where you'll eat small amounts of a trigger food to see if you have a reaction. Because you could have a life-threatening allergic reaction, this should only ever be done in your allergist's office or a hospital setting, and only under direct medical supervision.[24]
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Question 9 of 10:

Can you be allergic to insect bites?

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    Yes, some people are allergic to things like bee or wasp stings. This can occur even if you aren't allergic to anything else, and the reactions can sometimes be pretty severe. Typically, you'll notice a quick reaction when you're bitten or stung, and there will likely be significant swelling at the site of the sting. Other symptoms might include:[25]
    • Itching or hives
    • Tightness of the chest
    • Wheezing
    • Cough
    • Trouble breathing
    • Anaphylaxis
Question 10 of 10:

Can people be allergic to medicine?

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    Yes, talk to your doctor right away if you think this is the case. Although it's important to take all of your medication as directed by your healthcare provider, if you think you're having an allergic reaction to something you've taken, stop using it right away and call the doctor. They'll work with you to determine if that's the cause of your symptoms, and if so, what else you might take instead. Some of the symptoms of a medication allergy might include:[26]
    • Hives, itching, or a rash
    • Swelling of your face
    • Wheezing or shortness of breath
    • Anaphylaxis
  2. 2
    Certain medications and conditions may make allergies more likely. You might be more likely to experience a drug allergy if you take medications like penicillin, certain pain relievers, chemotherapy drugs, or medicines that treat autoimmune diseases. Other things that might increase your risk include:[27]
    • Having other allergies, like hay fever
    • Taking the drug for a long time or at high doses
    • Having certain illnesses like HIV
    • Having a history or family history of allergies to other medicines.
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Expert Q&A
Did you know you can get expert answers for this article? Unlock expert answers by supporting wikiHow

  • Question
    Can you be allergic to natural products?
    Mohiba Tareen, MD
    Mohiba Tareen, MD
    FAAD Board Certified Dermatologist
    Mohiba Tareen is a board certified Dermatologist and the founder of Tareen Dermatology located in Roseville, Maplewood and Faribault, Minnesota. Dr. Tareen completed medical school at the University of Michigan in Ann Arbor, where she was inducted into the prestigious Alpha Omega Alpha honor society. While a dermatology resident at Columbia University in New York City, she won the Conrad Stritzler award of the New York Dermatologic Society and was published in The New England Journal of Medicine. Dr. Tareen then completed a procedural fellowship which focused on dermatologic surgery, laser, and cosmetic dermatology.
    Mohiba Tareen, MD
    Mohiba Tareen, MD
    FAAD Board Certified Dermatologist
    Expert Answer

    Support wikiHow by unlocking this expert answer.

    Absolutely. If something is natural, it doesn't automatically mean it's safe to use or that you can't be allergic to it. You can be allergic to nuts, for example, and a natural shea butter product is made out of nuts. That's going to cause a reaction. If a natural product is irritating your skin, stop using it.
  • Question
    How can I fix a sensitivity or allergy to a scent?
    Alan O. Khadavi, MD, FACAAI
    Alan O. Khadavi, MD, FACAAI
    Board Certified Allergist
    Dr. Alan O. Khadavi is a Board Certified Allergist and a Pediatric Allergy Specialist based in Los Angeles, California. He holds a BS in biochemistry from the State University of New York (SUNY) at Stony Brook and an MD from the State University of New York Health Science Center at Brooklyn. Dr. Khadavi completed his pediatric residency at Schneider Children’s Hospital in New York, and then went on to complete his allergy and immunology fellowship and pediatric residency at Long Island College Hospital. He is board certified in adult and pediatric allergy/immunology. Dr. Khadavi is a Diplomate of the American Board of Allergy and Immunology, a Fellow of the American College of Allergy, Asthma & Immunology (ACAAI), and a member of the American Academy of Allergy, Asthma & Immunology (AAAAI). Dr. Khadavi's honors include Castle Connolly’s list of Top Doctors 2013-2020, and Patient Choice Awards "Most Compassionate Doctor" in 2013 & 2014.
    Alan O. Khadavi, MD, FACAAI
    Alan O. Khadavi, MD, FACAAI
    Board Certified Allergist
    Expert Answer

    Support wikiHow by unlocking this expert answer.

    There are medications you can get to help mitigate the symptoms, but unfortunately, there's no perfect cure out there. You can try not using too much hand sanitizer or cleaning chemicals, but it's really just about avoiding the trigger at that point.
  • Question
    Why do I always get allergies in Autumn?
    Alan O. Khadavi, MD, FACAAI
    Alan O. Khadavi, MD, FACAAI
    Board Certified Allergist
    Dr. Alan O. Khadavi is a Board Certified Allergist and a Pediatric Allergy Specialist based in Los Angeles, California. He holds a BS in biochemistry from the State University of New York (SUNY) at Stony Brook and an MD from the State University of New York Health Science Center at Brooklyn. Dr. Khadavi completed his pediatric residency at Schneider Children’s Hospital in New York, and then went on to complete his allergy and immunology fellowship and pediatric residency at Long Island College Hospital. He is board certified in adult and pediatric allergy/immunology. Dr. Khadavi is a Diplomate of the American Board of Allergy and Immunology, a Fellow of the American College of Allergy, Asthma & Immunology (ACAAI), and a member of the American Academy of Allergy, Asthma & Immunology (AAAAI). Dr. Khadavi's honors include Castle Connolly’s list of Top Doctors 2013-2020, and Patient Choice Awards "Most Compassionate Doctor" in 2013 & 2014.
    Alan O. Khadavi, MD, FACAAI
    Alan O. Khadavi, MD, FACAAI
    Board Certified Allergist
    Expert Answer

    Support wikiHow by unlocking this expert answer.

    Autumn allergies are usually ragweed's fault. Keep your windows closed, don't spend a ton of time outside, run air conditioning inside of the house, and stay inside from 5-10 am. This should dramatically limit your exposure.
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Warnings

  • If you experience any signs of an allergic reaction, see your doctor. If the reaction is severe, get emergency medical assistance right away.
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References

  1. ↑ https://acaai.org/allergies/symptoms/
  2. ↑ https://www.nhs.uk/conditions/allergies/symptoms/
  3. ↑ Alan O. Khadavi, MD, FACAAI. Board Certified Allergist. Expert Interview. 29 July 2020.
  4. ↑ https://my.clevelandclinic.org/health/diseases/8619-anaphylaxis
  5. ↑ https://newsinhealth.nih.gov/2014/10/cold-flu-or-allergy
  6. ↑ https://health.clevelandclinic.org/what-the-color-of-your-snot-really-means/
  7. ↑ https://www.allergy.org.au/patients/allergy-testing/causes-of-allergy
  8. ↑ https://www.nhs.uk/conditions/allergies/symptoms/
  9. ↑ https://acaai.org/allergies/allergy-treatment/diagnosing-allergies
  1. ↑ https://www.nhs.uk/conditions/allergies/diagnosis/
  2. ↑ https://acaai.org/allergies/allergy-treatment/diagnosing-allergies
  3. ↑ https://acaai.org/allergies/allergy-treatment/diagnosing-allergies
  4. ↑ https://my.clevelandclinic.org/health/diseases/8610-allergy-overview
  5. ↑ https://allergyasthmanetwork.org/allergies/
  6. ↑ https://allergyasthmanetwork.org/allergies/
  7. ↑ https://allergyasthmanetwork.org/allergies/
  8. ↑ https://allergyasthmanetwork.org/allergies/
  9. ↑ https://medlineplus.gov/ency/article/000813.htm
  10. ↑ https://community.aafa.org/blog/sneezing-and-sniffling-how-to-tell-if-its-allergies-or-a-cold-and-warning-for-people-with-asthma
  11. ↑ https://medlineplus.gov/ency/article/000869.htm
  12. ↑ https://acaai.org/allergies/allergic-conditions/food/
  13. ↑ https://www.foodallergy.org/resources/food-elimination-diet
  14. ↑ https://www.eatingwell.com/article/7805580/elimination-diet-meal-plan/
  15. ↑ https://kidshealth.org/en/parents/food-allergies.html
  16. ↑ https://acaai.org/allergies/allergic-conditions/insect-sting-allergies/
  17. ↑ https://acaai.org/allergies/allergic-conditions/drug-allergies/
  18. ↑ https://acaai.org/allergies/allergic-conditions/drug-allergies/
  19. ↑ https://acaai.org/allergies/allergy-treatment/diagnosing-allergies
  20. ↑ https://my.clevelandclinic.org/health/diseases/10009-food-problems-is-it-an-allergy-or-intolerance
  21. ↑ https://kidshealth.org/en/parents/food-allergies.html

About This Article

Alan O. Khadavi, MD, FACAAI
Co-authored by:
Alan O. Khadavi, MD, FACAAI
Board Certified Allergist
This article was co-authored by Alan O. Khadavi, MD, FACAAI and by wikiHow staff writer, Amy Bobinger. Dr. Alan O. Khadavi is a Board Certified Allergist and a Pediatric Allergy Specialist based in Los Angeles, California. He holds a BS in biochemistry from the State University of New York (SUNY) at Stony Brook and an MD from the State University of New York Health Science Center at Brooklyn. Dr. Khadavi completed his pediatric residency at Schneider Children’s Hospital in New York, and then went on to complete his allergy and immunology fellowship and pediatric residency at Long Island College Hospital. He is board certified in adult and pediatric allergy/immunology. Dr. Khadavi is a Diplomate of the American Board of Allergy and Immunology, a Fellow of the American College of Allergy, Asthma & Immunology (ACAAI), and a member of the American Academy of Allergy, Asthma & Immunology (AAAAI). Dr. Khadavi's honors include Castle Connolly’s list of Top Doctors 2013-2020, and Patient Choice Awards "Most Compassionate Doctor" in 2013 & 2014. This article has been viewed 108,545 times.
20 votes - 66%
Co-authors: 29
Updated: June 8, 2022
Views: 108,545
Categories: Featured Articles | Allergies

Medical Disclaimer

The content of this article is not intended to be a substitute for professional medical advice, examination, diagnosis, or treatment. You should always contact your doctor or other qualified healthcare professional before starting, changing, or stopping any kind of health treatment.

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