Allergies: Prevention & Treatment

Be prepared for seasonal and chronic allergies.

For most people, allergies mean itchy eyes and a drippy nose. But for a few people, allergies to things like bee stings or nuts cause a whole-body reaction that can be life-threatening. Whether your allergies are dangerous or just annoying, the information below can help you cope.


Table of Contents:
  1. Allergic Rhinitis
  2. Avoiding Allergy Triggers
  3. Food Allergies
  4. Drug Allergies
  5. Insect Sting Allergies

Allergic Rhinitis (including seasonal allergies)

What is allergic rhinitis?

Allergies happen when you are exposed to certain particles in the air (allergens). Your body's defense system (immune system) overreacts to certain substances. The immune system may treat a harmless substance as if it were a harmful germ or virus. Many things can cause this problem. You can be allergic to things such as pollens, dust, or animal dander.

Your allergies can be mild or severe. Mild allergies can be managed with home treatment. But medicine may be needed to prevent problems.

When allergies aren't treated, they can affect your health. You may have problems such as sinusitis, plugged ears, and ear infections. Allergies can also affect your quality of life. You may avoid seeing people, have problems sleeping, and feel tired or grumpy.



You may be more likely to have allergic rhinitis and other allergies if:

  • You have a family history of allergies, especially allergic rhinitis. A child is more likely to have an allergy if both parents have an allergy or have the same type of allergy.
  • You are exposed to dust mites, animal dander, or other indoor allergens.
  • You are exposed to pollens or molds.


Allergy symptoms may start within minutes or hours after you breathe in an allergen. And the symptoms can last for days.

When symptoms start right away, you may sneeze over and over again. This often happens after you wake up in the morning. You may have a tickle in your throat or coughing caused by postnasal drip. Your nose may be runny. And your eyes may be watery and itchy. Your ears, nose, and throat may also be itchy.

Other symptoms may take longer to appear. For example, you may have a stuffy nose. You may feel pressure in one or both ears, or have pain in your face. Your eyes may be sensitive to light. You may also have a long-lasting cough. Some people notice dark circles under their eyes.

Your symptoms may be better or worse at different times of the year.


Call your doctor if:

  • You have pain in the sinus area and other symptoms of sinus infection. (Symptoms may include fever or a creamy, yellow or green discharge from the nose.)
  • Your allergy symptoms get worse and you don't know why.
  • You are taking a prescription or over-the-counter allergy medicine that does not help your symptoms.
  • Your allergy medicine is causing side effects that bother you, such as decreased coordination or increased drowsiness.
  • You have a fever or ear pain.
  • You have a cough or cold that lasts longer than 1 to 2 weeks.
  • You have severe itching of the eyes or nose.
  • Your allergy disturbs your life.


You may need to see an allergy specialist (allergist). This depends on your symptoms or which other treatments you may need. For example, you may need to see a specialist if your medicines are not working or cause severe side effects. Another reason is if you are thinking about getting immunotherapy (such as allergy shots).

Your doctor may refer you to an ear, nose, and throat (ENT) specialist (also called an otolaryngologist or otorhinolaryngologist). An ENT specialist may be helpful if your doctor thinks you may have nasal polyps or other things blocking your nose.


Your doctor can most often diagnose allergic rhinitis by doing a physical exam and asking you questions about your symptoms, activities, and home.

You may need allergy tests if:

  • You and your doctor need to find out exactly what things you are allergic to. And then you can take steps to avoid them.
  • Treatment is not helping your symptoms.
  • You have severe symptoms.
  • You are thinking about trying immunotherapy (such as allergy shots).
  • A skin test can show how your skin reacts to an allergen. Or a blood test can measure the level of antibodies that your body makes in response to certain allergens.

These tests can help your doctor know what is causing your symptoms and find the best treatment.

Allergy testing involves having a skin or blood test to find out what substance, or allergen, may trigger an allergic response in a person. Skin tests are usually done because they are rapid, reliable, and generally less expensive than blood tests, but either type of test may be used.

Your allergy test results may show that allergy treatment is a choice for you.


There are three main treatments for allergic rhinitis:

  • Avoid the things you are allergic to (allergens). For example, you may need to clean your house often to get rid of animal dander. Or you may need to stay indoors when pollen counts are high.
  • Manage your symptoms with medicine. Over-the-counter corticosteroid nasal spray, antihistamine or decongestant pills, or prescription nasal spray antihistamines may help relieve some of your symptoms.
  • Get immunotherapy (such as allergy shots). For this treatment, you get shots or take pills that have a small amount of certain allergens in them. Your body "gets used to" the allergen, so you react less to it over time.

Medicines are a key part of treatment for allergic rhinitis. 

You can get corticosteroid nasal sprays over-the-counter or by prescription. These help reduce inflammation in the nose. They work well for most people. They start working quickly, but it may be several weeks before you get the full effect.

There are other types of allergy medicines you can buy with or without a prescription:


Taking care of yourself is an important part of staying healthy when you have allergies.

Your doctor will help you find out what may be causing your allergies. As soon as you know what triggers your symptoms, try to avoid those things. This can help prevent allergy symptoms, asthma, and other health problems.

There are steps you can take to avoid your allergy triggers. For example, if you are allergic to house dust, it helps to wash your bedding in hot water each week. If your allergies are caused by pollen, try to stay inside when pollen counts are high. It also helps to stay away from smoke. Being around smoke can make your allergies worse.

Ask your doctor about allergy medicine, including over-the-counter medicine. There may also be other treatments that can help reduce or prevent allergy symptoms.

Minimizing Allergies: Avoiding Triggers 

How do I control indoor and outdoor allergies?

When you have allergies, you may feel better or worse at different times of the year. Learning what triggers your allergy symptoms will help you manage and treat your allergies. Managing your allergies is an important part of your health and can help you avoid other problems.


Work with your doctor to find out what you're allergic to. When you know what triggers your allergies, you can take steps to control those allergens in your home. It's especially important to prevent allergens in your bedroom.


Clean often: Regular housecleaning can help prevent allergens from building up.

Control animal dander and other pet allergens: For example, keep pets out of your bedroom. Keep your pet in areas that have hard floors, which are easier to clean than carpeted floors.

Remove items where allergens build up: Examples include stuffed animals and rugs.

Avoid indoor air pollution:

  • Polluted air doesn't cause allergies, but it can irritate the nose and lungs. This may make it more likely that you will have symptoms.
  • Avoid tobacco smoke, smoke from wood-burning stoves, and fumes from kerosene heaters.
  • If you have a wood-burning stove, try to use one that is airtight and doesn't leak smoke into your home.


Dust and dust mites are a common indoor allergen. Allergens are things that can trigger an allergic reaction. Allergens can cause a rash, a stuffy nose, or other symptoms such as wheezing or coughing.

Dust mites are visible only through a microscope. People are allergic to dust mite droppings, not the dust mites themselves. Allergy to dust mites is a year-round problem. 


For example, clean bathtubs and showers with soap and water, mold-killing products, or liquid bleach mixed with water. Try to keep your house aired out and dry.

Indoor mold (fungus) is very common in humid areas and in homes that have damp areas such as basements. Mold may trigger symptoms, such as wheezing or coughing, or another allergic reaction, such as the rash of atopic dermatitis or the stuffy nose of allergic rhinitis. Substances that trigger these reactions are called allergens.

Mold can get into a building through open doorways, windows, vents, and heating and air conditioning systems. Mold in the air outside can also attach itself to clothing, shoes, bags, and pets and can be carried indoors. Mold will grow in places that have a lot of moisture, such as around leaky roofs, windows, or pipes, or flooded areas. Mold grows well on paper products, cardboard, ceiling tiles, and wood products. Mold can also grow in dust, paints, wallpaper, insulation, drywall, carpet, and fabrics. 


The following tips can help you avoid pollens, even if you don't know what type of pollen you are allergic to. If you do know, you can fine-tune these tips for that type of pollen. 


Mold may cause allergies that get worse in damp weather. Mold also produces spores that move around in outdoor air during warmer months. By taking the following precautions, you may have fewer or less severe symptoms. 

Food Allergies

What is a food allergy?

When you have a food allergy, your body thinks certain foods are trying to harm you. Your body fights back by setting off an allergic reaction. In most cases, the symptoms are mild—a rash or an upset stomach. A mild reaction is no fun, but it isn't dangerous. A serious reaction can be deadly. But quick treatment can stop a dangerous reaction.

Food allergies are more common in children than in adults. Children sometimes outgrow their food allergies, especially allergies to milk, eggs, or soy. But if you develop a food allergy as an adult, you will most likely have it for life.

Many people think they have a food allergy, but in fact they have food intolerance. An intolerance can cause some of the same symptoms as a mild food allergy, like an upset stomach. It can make you feel bad, but it isn't dangerous.

Food intolerances are much more common than food allergies. True food allergies are a reaction to food or food additives by your body's immune system. But a food intolerance doesn't cause an allergic reaction.



Food allergies occur when your body's immune system overreacts to substances in food you have eaten. This triggers an allergic reaction. Food allergies are more common in young children than in adults.

  • Milk, eggs, peanuts, tree nuts, fish, shellfish, wheat, and soy cause most problems in children. Some babies are so sensitive to these foods that if the food is eaten by the mother, drinking her breast milk can cause a reaction. Most children outgrow allergies to eggs, milk, wheat, and soy.
  • Peanuts, tree nuts, fish, and shellfish cause most of the allergic reactions in teens and adults. Adults typically remain allergic to the food for life.

If you are highly sensitive to a certain food, you may have an allergic reaction just by being near where the food was prepared or served.


Food allergies can cause many different symptoms. They can range from mild to serious. A mild reaction may include tingly lips, a stuffy nose, dizziness, and a few raised, red, itchy patches of skin (called hives).

The most severe reaction is called anaphylaxis. It affects your whole body. Anaphylaxis can start within a few minutes to a few hours after you eat the food. The symptoms can go away and come back hours later. A severe reaction may cause hives all over, swelling in the throat, trouble breathing, nausea or vomiting, or fainting.

Your doctor will ask questions about your past health and family food allergies. And he or she will do a physical exam. Your doctor will also ask what symptoms you have when you eat certain foods.

Because food allergies can be confused with other problems, your doctor may do some tests. You may have either skin testing or a blood test. These tests help to see what you are allergic to. An oral food challenge is another way to diagnose a food allergy. You will eat a variety of foods that may or may not cause an allergic reaction. Your doctor watches to see if and when a reaction occurs.

The best treatment for allergic reactions to food is to avoid the food that causes the allergy. When that isn't possible, you can use medicines such as antihistamines for mild reactions and epinephrine for serious reactions. Epinephrine is a shot that you can give yourself when needed.

Drug Allergies

What is a drug allergy?

A drug allergy occurs when your immune system overreacts to something in a medicine. Your body's immune system fights back by setting off an allergic reaction. Most drug allergies are mild, and the symptoms go away within a few days after you stop using the medicine. But some drug allergies can be very serious.

Some drug allergies go away with time. But after you have an allergic reaction to a drug, you will probably always be allergic to that drug. You can also be allergic to other drugs that are like it.

A drug allergy is one type of unwanted, or adverse, drug reaction. There are other kinds of adverse drug reactions. Symptoms and treatments of different kinds of adverse reactions vary. So your doctor will want to find out if you have a true drug allergy or if you have side effects that are not as serious.



Any medicine can cause an allergic reaction. A few of the most common ones are:

  • Penicillins (such as ampicillin or amoxicillin).
  • Sulfa medicines.
  • Anesthesia.
  • Aspirin and other nonsteroidal anti-inflammatory drugs.

If you are allergic to one medicine, you may be allergic to others like it. For example, if you are allergic to penicillin, there is a chance that you may also be allergic to similar medicines, such as amoxicillin.


The symptoms of a drug allergy can range from mild to very serious. Most of the time they appear within 1 to 72 hours. They include:

  • Hives, a rash, and itchy skin.
  • Coughing, wheezing, a runny nose, and trouble breathing.
  • A fever.
  • Serious skin conditions that make your skin blister and peel. These include toxic epidermal necrolysis and Stevens-Johnson syndrome.
  • Anaphylaxis, which is the most dangerous reaction. It can be deadly, and you will need emergency treatment. Symptoms include hives all over your body, trouble breathing, nausea or vomiting, swelling of the throat or mouth, and/or feeling very lightheaded. These usually appear within 1 hour after you take the medicine. Without emergency care, you could die.

Your doctor will diagnose a drug allergy by asking you questions about the medicines you take and about any medicines you have taken in the recent past. Your doctor will also ask about your past health and your symptoms. Your doctor may do a physical exam.

If this doesn't tell your doctor whether you have a drug allergy, you may need skin tests. Or your doctor may have you take small doses of a medicine to see if you have a reaction.


If you have severe drug allergies, your doctor may give you an epinephrine auto-injector. Your doctor will teach you how to use it. If you have a serious allergic reaction, you may need to give yourself the shot and get emergency medical treatment.

Inject epinephrine into the thigh muscle if you have signs of a severe allergic reaction, such as trouble breathing, having hives all over your body, or feeling faint. Call 911 right away.

If you have a mild allergic reaction, over-the-counter (OTC) antihistamines may help your symptoms. Mild symptoms include sneezing or an itchy or runny nose; an itchy mouth; a few hives or mild itching; and mild nausea or stomach discomfort. You may need prescription medicine if OTC antihistamines don't help or if you have problems with side effects, such as drowsiness. Not all OTC antihistamines cause drowsiness.

The best thing you can do for a drug allergy is to stop taking the medicine that causes it. Talk to your doctor to see if you can take another type of medicine.

If you can't change your medicine, your doctor may try a method called desensitization. This means that you will start to take small amounts of the medicine that caused your reaction. Under your doctor's supervision, you will then slowly increase how much you take. This lets your immune system "get used to" the medicine. After this, you may no longer have an allergic reaction.

Be sure to wear a medical alert bracelet or other jewelry that lists your drug allergies. If you are in an emergency, this can save your life.


To take care of yourself at home:

  • Know which medicines you're allergic to, and avoid taking these medicines.
  • Keep a list of all medicines you are taking.
  • Talk with your doctor or pharmacist about any new medicines you are prescribed. Make sure they are not similar to those that can cause a reaction.
  • Don't use someone else's medicines or share yours.

If you do have a mild reaction, take steps to relieve symptoms such as itching. Take cool showers, or apply cool compresses. Wear light clothing that doesn't bother your skin. Stay away from strong soaps and detergents, which can make itching worse.

Insect Sting Allergies 

What are insect sting allergies?

An allergic reaction to a sting occurs when your body's immune system overreacts to substances called allergens in the venom of stinging insects such as bees, wasps, hornets, or fire ants.

There are different types of allergic reactions to stings including minor localized reactions, large local reactions, and systemic reactions (which includes life-threatening reactions such as anaphylaxis).



Minor allergic reactions occur around the site of the sting. This is called a localized reaction, and it can cause pain, itching, redness, swelling, and hives near the site of the sting.


Large local reactions may cause the same symptoms as mild reactions, plus redness and swelling that affects large parts of your body, such as an entire arm or leg.


Systemic reactions are those that spread throughout your body. One type may only involve your skin, causing hives or deeper skin swelling (a cutaneous reaction), but it does not affect the tongue or throat or cause breathing problems. A more serious type of systemic reaction can cause symptoms such as swelling of the tongue, throat, or other body parts. A life-threatening systemic allergic reaction called anaphylaxis can cause severe symptoms such as confusion, trouble breathing, shock, and sometimes death.


If you have had severe reactions to insect stings in the past, you may want to get a series of allergy shots on a faster schedule, called "rush immunotherapy." For this you get allergy shots every few hours on one day or every few days. This helps to rapidly increase your tolerance to an allergen. After the first shot, you must wait to see if you have a reaction to the shot. If you don't have a reaction, you get more shots throughout the day. You (or your child) may feel anxious about receiving the next shot. So it may help to bring a book or something to distract you while you wait. Rush immunotherapy is usually done by a specialist. Having a severe reaction to this treatment is more likely than with standard allergy shots.

This treatment usually works in 1 to 8 days instead of the standard treatment, which takes several months. You may have this "rush" treatment if you have severe or life-threatening allergic reactions to insect stings, are a long distance from any type of health care center, or are about to travel.


Allergy shots work by putting small amounts of insect venom into your body, making you less sensitive over time to the venom.

Getting a series of allergy shots can prevent a systemic allergic reaction or make it less severe. Allergy shots aren't needed if you have a mild reaction, a large local reaction, or even a systemic reaction that only affects your skin. Only about 4 to 10 people out of 100 who have these kinds of reactions to insect stings go on to have a more serious, anaphylactic reaction. This means that 90 to 96 out of 100 people who have localized reactions don't ever have an anaphylactic reaction to an insect sting.footnote1

Allergy shots can greatly reduce your risk of having another life-threatening reaction if you've had one before. Imagine a group of 100 people who have had a life-threatening reaction. Without allergy shots, up to 60 of those 100 people will have another life-threatening reaction in the future. But if those 100 people get allergy shots, only 5 of them will have another life-threatening reaction. This treatment is most effective after an entire course of allergy shots is complete.

After allergy tests have identified the insect(s) you are allergic to, you can begin to get the shots. At first, you will get weekly shots of small doses of venom and allergens from the insect(s) that cause your allergies. After about 4 to 6 months of weekly shots, you will get a regular dose, called a maintenance dose, every 4 weeks for 3 to 5 years, depending on the type of stings that cause your allergies. For example, fire ant allergies require longer treatment than other stinging insect allergies.

Allergy Shot Risks & Doctor Recommendations

Allergy shots are safe for most people. The most common side effects are redness and warmth at the injection site. Some people may have large local reactions that include itching, hives, or swelling of the skin near the injection site.

But allergy shots can trigger a more serious reaction, which may include trouble breathing or swelling in the deep layers of the skin. In rare cases, a person may have a life-threatening allergic reaction (anaphylaxis) to the shots. Because of this, the shots are given in a clinic or other health care setting where emergency care can be provided if needed.

Talk with your doctor if you have an autoimmune disease (such as lupus) or are taking medicine for heart problems (such as beta-blockers or ACE inhibitors). Allergy shots may not be safe for you.

Current as of: February 27, 2023

Author: Healthwise Staff

Medical Review: E. Gregory Thompson MD - Internal Medicine; Adam Husney MD - Family Medicine; Martin J. Gabica MD - Family Medicine; Kathleen Romito MD - Family Medicine; Rohit K Katial MD - Allergy and Immunology