Allergies Allergies Guide Allergies Guide Symptoms Causes Diagnosis Treatment Coping Symptoms of Allergies By Daniel More, MD Daniel More, MD, is a board-certified allergist and clinical immunologist with a background in internal medicine. Learn about our editorial process Daniel More, MD Medically reviewed by Medically reviewed by John Carew, MD on January 02, 2020 twitter linkedin John Carew, MD, is board-certified in otolaryngology and is an adjunct assistant professor at New York University Medical Center. Learn about our Medical Review Board John Carew, MD Updated on June 16, 2021 Print Table of Contents View All Table of Contents Frequent Symptoms Rare Symptoms Complications/Sub-Groups When to See a Doctor Frequently Asked Questions Next in Allergies Guide Why Do You Get Allergic Reactions? Allergy symptoms can vary widely, but they all are the product of an abnormal immune system reaction to a normally harmless substance (an allergen). When a person who is allergic encounters the trigger, the body reacts by releasing chemicals that affect the skin, respiratory system, digestive tract, and more to produce allergy symptoms. These can range from a runny nose to an itchy rash or even to a life-threatening asthma attack or anaphylactic reaction. Sollina Images Collection / Photodisc / Getty Images Frequent Symptoms In children, allergic disease first occurs as atopic dermatitis (eczema) or food allergies. Children with atopic dermatitis are then at an increased risk of developing allergic rhinitis and asthma; both are more likely to occur in school-age children. Typically, atopic dermatitis goes away by adulthood, as do many types of food allergies. Allergic rhinitis and asthma, however, most often start during the adolescent, teenage, and young adult years, and are likely to persist throughout a person’s life. The severity of allergic symptoms, however, may wax and wane, and even temporarily disappear. There can be some overlap of allergy symptoms between types of allergies, so it's best to consider what is most frequently associated with which conditions. Atopic Dermatitis Atopic dermatitis, or eczema, is typically the first sign of allergies and is seen in 10% to 20% of all children, frequently during infancy. It is characterized by itching, with rash formation at the sites of scratching. The rash is typically red and dry, may have small blisters, and can flake and ooze over time. In infants and very young children, this rash involves the face (especially the cheeks), chest and trunk, back of the scalp, and may involve the arms and legs. This distribution reflects where the child is able to scratch, and therefore usually spares the diaper area. The location of the rash changes in older children and adults to classically involve the skin in front of the elbows and behind the knees. Food and environmental allergies have been shown to worsen atopic dermatitis. How to Treat and Prevent Eczema Food Allergy Food allergies can occur at any age. Almost all people with food allergies will have a skin symptom as a result of eating the culprit food. These symptoms typically occur within a few minutes of eating the food in question, although they can be delayed up to several hours. Skin symptoms may include: Hives Swelling Itching Redness of the skin Other symptoms of food allergies can include: Nausea Vomiting Stomach aches Diarrhea Breathing difficulties (asthma symptoms) Runny nose Sneezing Lightheadedness In some cases, children can experience a severe allergic reaction called anaphylaxis, which can be life-threatening. Crash Course on the Most Common Food Allergens Nasal Allergies Allergic rhinitis, including hay fever and seasonal allergies, occurs in up to 30% of adults and up to 40% of children. Symptoms of allergic rhinitis include: Sneezing Runny nose Itchy nose and eyes Nasal congestion Some people may also experience post-nasal drip, allergic shiners (dark circles under the eyes), and a line across the nasal bridge from an upward rubbing of the palm of the hand on the nose, a sign called the “allergic salute.” The tissues of the sinuses can also be swollen in an allergic reaction, which can result in pressure inside the head and produce a sinus headache. Fatigue from disrupted sleep is another potential symptom of nasal allergies. Nasal Allergy Symptoms Contact Dermatitis Some skin allergy symptoms are triggered when your skin comes in contact with an irritant or allergen. Common triggers include nickel, latex, fragrances, poison ivy, hair products, and skin medications. You may experience these skin symptoms: Rash Blisters Burning Itching You won't usually have the reaction the first time you come into contact with the allergen. But on a future exposure, you will have symptoms. Contact Dermatitis Rare Symptoms Anaphylaxis is a life-threatening allergic reaction that can be triggered by exposure to many different substances (allergens). The most common allergies that can produce anaphylaxis are to drugs, insect stings, foods, and latex. The most common symptoms of anaphylaxis are: Swelling of the face, tongue, lips, throat, or limbs Hives Breathing problems including coughing, wheezing, and difficulty taking a breath Low blood pressure, which may lead to confusion or dizziness Other symptoms include an irregular heartbeat, chest pain, nausea, vomiting, cramping, and headaches. Anaphylaxis is a medical emergency. If you are symptoms of anaphylaxis, call 911 and use an epinephrine injector if you have one. This condition can progress rapidly and be fatal. What Allergies Can Trigger Anaphylaxis? Complications/Sub-Group Indications Allergies can contribute to developing or worsening other conditions. Asthma Allergies are a major cause of asthma, a condition that occurs in about 8% of all people. Though it can occur at any age, it is most often seen in males in the pre-teen years and in females in the teenage years. In fact, asthma is the most common chronic disease in children and young adults. Sometimes asthma is difficult to diagnose in very young children and may require a physician who is an asthma specialist. Symptoms of asthma may include: Coughing: This can be the only symptom in some people who have what's called cough-variant asthma. The cough is often dry, hacking, and may be worse with allergic triggers and after exercise. The cough may only be present at night. Cold air may also trigger this symptom. Wheezing: This is a high-pitched, musical instrument-like sound that can occur with breathing in and out in people with asthma. Wheezing usually occurs along with other asthma symptoms and may get worse with exercise and allergic triggers. Shortness of breath: Most people with asthma feel as if they’re not getting enough air at times, particularly when they are physically exerting themselves or when an allergic trigger is present. People with more severe asthma have shortness of breath at rest or wake-up with this symptom during the night. Chest tightness: Some people describe this as a sensation that someone is squeezing or hugging them. Children may say that their chest hurts or feels “funny.” Signs and Symptoms of Asthma Nasal Allergy Complications Nasal allergies can put you at more risk of developing respiratory infections, including lung infections, sinus infections, sinusitis, and middle ear infections (otitis media and otitis media with effusion). Hearing impairment can result. You may also develop nasal polyps, which are growths in the sinuses or nasal lining. Migraine headaches are also associated with allergies. When nasal allergies impair sleep, you can have daytime fatigue and poor mental functioning. The medications prescribed can likewise have effects on performance. Co-Existing Conditions Over-the-counter medications used to treat allergy symptoms can be unsafe to take if you are being treated for a variety of health conditions including heart disease, diabetes, high blood pressure, thyroid disease, and more. If you are under treatment for any condition, talk to your doctor before you begin taking an allergy remedy. It may interact with prescription medications or worsen your condition. When to See a Doctor If you are unable to control your allergies with the occasional use of over-the-counter medications, see your physician. You should also see your doctor if your symptoms are impairing your quality of life, reducing productivity at work or school, or disturbing your sleep. Allergy symptoms in children and older people should always be checked by a physician so appropriate medications can be used, including those available without a prescription, and dangerous interactions avoided. Frequently Asked Questions What are the signs and symptoms of a food allergy? The symptoms can vary, with some people experiencing more severe reactions than others. Common symptoms include: Tingling or itching in the mouth Nasal congestion Hives or angioedema (tissue swelling) Itchiness Stomach pain Nausea or vomiting Diarrhea Trouble breathing Dizziness or lightheadedness What are the symptoms of wheat allergy? The symptoms are more or less the same as any food allergy. However, wheat allergy is often mistaken for gluten intolerance, and vice versa. Conditions like celiac disease (CD) or non-celiac gluten sensitivity (NCGS) are not allergies but can cause many of the same symptoms. Because the treatment of these conditions differs, an evaluation from a gastroenterologist may be needed. What are the symptoms of seasonal allergy? Common symptoms of seasonal allergies (including hay fever) include: Sneezing Stuffy or runny nose Red, watery, and itchy eyes Cough Itchy nose or throat Swollen, dark circles under the eyes Fatigue Are spring allergy symptoms worse in the morning? They can be, simply because pollen counts tend to be higher in the morning and decrease as temperatures rise. Morning symptoms may also be due to pollen, molds, and dust mites that are circulated through heating or air conditioning while you sleep. Cooler temperatures at night may also increase your risk of nighttime allergies as pollen counts once again start to rise. What are the symptoms of allergic contact dermatitis? Signs and symptoms of allergic contact dermatitis can vary but may involve: Rash or hives Areas of inflamed, red skin Itchiness, often intense Dry, scaly skin Burning or tingling sensations Blistering, oozing areas of skin Symptoms tend to develop within 72 hours of contact with allergens like latex, nickel, poison ivy, and others. How do antihistamines reduce allergy symptoms? Antihistamines block a chemical called histamine that is released by the immune system in response to an allergen. Histamine triggers allergy by causing blood vessels to widen and tissues to swell, leading to nasal congestion, red eyes, rash, and other characteristic symptoms. Blocking histamine prevents or reverses these effects, relieving symptoms. What are the signs of a severe allergy? A potentially life-threatening, whole-body allergy known as anaphylaxis is recognized by the rapid onset of symptoms, usually within minutes to hours of exposure to an allergen. Call 911 or seek emergency care if you develop any of the following signs of anaphylaxis, including: Hives or rash Shortness of breath Wheezing Rapid or irregular heartbeat Nausea, vomiting, or diarrhea Swelling of the tongue, throat, or neck Dizziness or fainting A feeling of impending doom A Word From Verywell Allergy symptoms can range from annoying to life-threatening, and ongoing symptoms don't have to simply be tolerated. See your doctor or an allergy specialist so you can learn how to avoid allergy triggers and which medications will most improve your quality of life. Was this page helpful? Thanks for your feedback! Sign up for our Health Tip of the Day newsletter, and receive daily tips that will help you live your healthiest life. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? 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