Allergy symptoms 101: Your complete guide

It can be easy to dismiss some symptoms as "just" allergies.

But even so-called small problems, like congestion and itchy eyes, can make life more challenging. Plus, severe allergy symptoms can even be life threatening.

No matter what they are, it is important to take those signs seriously. Treatment can help you live better with allergies.

The first step? Learn everything you can about what you're dealing with.

Let's get into it.

What are allergies?

There's nothing inherently dangerous about pollen or milk. But some people's bodies mistake these things as threats. Their immune systems go on the attack to try to get rid of those harmless invaders (aka allergens).

The result? Allergy symptoms.

Allergens can include:

• Things you swallow, like food or medicine
• Particles you breathe in, like pollen, dust, mold, and pet dander (flakes of skin)
• Substances you brush up against, like poison ivy

How the allergic response works

During exposure to an allergen, your body sets off a chain of events, said Irene Paek, MD. She's an allergist and immunologist at ProHEALTH Care Associates, part of Optum, in Bethpage, New York:

• Step 1: Your body overreacts and releases a chemical called histamine.¹
• Step 2: Histamine kicks off different processes within your body to manage the threat.¹ It can fire up your nerves and cause itching. It might also lead to a runny nose.
• Step 3: You react to the histamine. Skin allergy symptoms might cause you to scratch your skin. Maybe a runny nose causes you to grab a tissue. Blowing your nose helps flush allergens from your system.

You can think of the allergic response as one big exaggeration. Your body is trying its hardest to protect itself from something that isn"t dangerous.

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Seasonal allergy symptoms

Symptoms of seasonal and indoor allergies can range from slight to severe.

The most common symptoms are:

• Congested or runny nose
• Red, itchy, watery eyes
• Sneezing
• Ear congestion
• Postnasal drip, which can cause a dry cough and irritated throat
• Itchiness and irritation in the sinuses and throat
• Headaches
• Coughing
• Feeling tired
• Skin rash or hives

Severe seasonal allergy symptoms can be very uncomfortable.

Skin allergy symptoms

Seasonal allergies can cause skin allergy symptoms. But you can also get them after touching an allergen or irritant like a plant or pet's saliva.

Symptoms can include:

• Rash
• Itchiness
• Redness or discoloration
• Raised bumps or swelling
• Cracked, irritated skin

Food allergy symptoms

Food allergies can cause symptoms far beyond your stomach. They can also affect your skin, heart, lungs, and airways.

Food allergy symptoms typically begin within 2 hours of eating. But most start within minutes.²

If you're allergic to a food, here's what you might experience after eating it:

• Vomiting
• Stomach cramps
• Hives
• Shortness of breath
• Difficulty swallowing
• Swelling of the tongue, affecting the ability to breathe or talk
• Coughing
• Dizziness

Very rarely, you can have a strong reaction that causes a sudden drop in blood pressure, known as anaphylactic shock. It's a life-threatening reaction.³

It's most common with food and drug allergies and insect stings. Anaphylactic shock can cause:

• Shortness of breath
• Throat swelling
• Dizziness
• Severe headaches
• Vomiting
• Fainting

If you go into anaphylactic shock, you'll likely need a shot of epinephrine. This relaxes your throat muscles, making it easier to breathe.³

Some people with food allergies carry an epinephrine injector (EpiPen) for emergencies. People allergic to stinging insects might also carry one.

Dr. Corriel explained that avoidance is the main way to stop food allergy symptoms. Your allergist may be able to help you create a plan to slowly expose you to that food.

Types of allergies

There's a wide range of substances that can cause allergy symptoms. They typically fall into one of several categories.

Seasonal and outdoor allergens

These happen when plants begin sprouting and pollinating. Depending on the season, different plants can cause allergy symptoms.

Common examples include pollen from:

• Trees
• Flowers
• Grass
• Ragweed

Foods

Even a small amount of a food allergen can cause a severe reaction.⁴

"A peanut allergy is the most pervasive food allergy," said Robert Corriel, MD. He's an allergist at ProHEALTH Lake Success Allergy, part of Optum, in New Hyde Park, New York. "It sticks around longest."

The most common food allergens are:²

• Peanuts
• Soy
• Wheat
• Eggs
• Shellfish
• Milk
• Tree nuts, such as walnuts and pecans

Stinging insects

Getting stung by a bee doesn't feel good for anyone. But stings can be dangerous for people who are allergic to the insect's venom.

Examples of stinging insects include:⁵

• Certain types of bees
• Hornets
• Yellowjackets
• Fire ants

Indoor allergens

If you have allergy symptoms indoors, especially in a home, the following may be to blame:⁶

• Dust
• Mold
• Cockroach droppings
• Pet dander

Medicines

All medicines have the potential to cause side effects. But for some people, medicines may cause an allergic reaction. Some people are even allergic to certain dyes in medications.⁷

"You can have allergic reactions to just about any medication on the planet," said Dr. Corriel.

If you think you're having an allergic reaction to your medicine, contact your doctor right away. If you're having severe symptoms, such as difficulty breathing, call 911.

Things you touch

When allergens affect your skin, you may have rashes, hives, and itching.

Plants, like poison ivy, are common culprits.

Other common allergens in this category include:

• Latex
• Fragrances
• Cosmetic ingredients
• Soaps
• Detergents

Have allergies that are mostly skin-related? Your doctor may suggest certain creams and ointments to ease itchiness and discoloration. In more severe cases, they may prescribe medication.

Are allergies hereditary?

There does appear to be a family link when it comes to allergies. Parents with allergies are more likely to have children with allergies, said Dr. Paek.

That's why an allergist will ask about your family history as part of your first exam. If multiple people in your family have allergies, you might also get them.

Learn more about allergies in kids.

When do allergies start?

Allergies can start at any age.

You may start to have allergies when you"re older, even if you've never had a problem in the past, says Dr. Corriel. You may have eaten shrimp your whole life, but it could start causing intense reactions seemingly out of the blue.

Seasonal allergies can also crop up later in life, Dr. Corriel added. That's because pollen seasons are getting longer and stronger due to climate change.

The good news? You're not always stuck with allergies once you have them.

"For the most part, allergies tend to wax and wane through life," said Dr. Corriel. "You can outgrow an allergy from childhood. Or you might need treatment as a child and then not as a young adult, even if you still have the allergy."

How are allergies diagnosed?

The most common allergy test is done on a small patch of skin, usually on your arm, Dr. Paek said.

A doctor will put a small amount of an allergen on your skin. About 15 minutes later, they will check your skin.

"If you have an allergy to something, you'll have an allergic response," said Dr. Paek. "You"ll have a small, itchy bump where the test was placed."

Blood work can also find specific allergies.¹

When your body finds an allergen, it makes a chemical called an antibody. Each antibody is specific to a single allergen. For example, you can be allergic to several kinds of pollen. Your body will create an antibody for each one. A blood test can find these antibodies and their levels in your blood.

Allergy treatment

Antihistamine medication is the main remedy for these symptoms. You can buy these medications over the counter at your local pharmacy or get a prescription from your doctor.

Common allergy medications include:

• Loratadine (Claritin, Alavert)
• Diphenhydramine (Benadryl)
• Cetirizine (Zyrtec)
• Fexofenadine (Allegra)
• Levocetirizine (Xyzal)

How do you combat dust, mold, or insect droppings that cause your allergies?

You may need a thorough home cleaning to help stop symptoms.

Can you prevent seasonal and indoor allergies?

There are ways to stop allergy symptoms before they start.

You might be able to keep your symptoms from happening entirely by:

• Using a nasal spray or bulb syringe with saline: Nasal sprays and bulb syringes can help flush allergens from your sinuses, which can ease itching and swelling.
• Trying eye drops: Eye drops can lubricate your eyes and rinse out allergens.
• Washing your sheets at least once a week in hot water: Keeping your linens clean can wash away allergens that might irritate your skin or eyes while you sleep.
• Keeping the clothing you wear outside far away from your bedroom: Getting undressed in the hallway or laundry room can keep allergens out of your bedroom.
• Showering after you've been outside: A shower can rinse pollen off your skin and hair. Shower steam can flush allergens from your sinuses.
• Paying attention to pollen counts: Plan outdoor activities based on when pollen counts are lowest. Pollen levels tend to peak in the morning. They can be higher on dry, windy, or hot days.
• Investing in an air purifier: High-efficiency particulate air (HEPA) filters are especially good at removing allergens from the air. They can remove more than 99% of allergens, including dust and pollen. Think about putting a HEPA filter in one room and keeping that room closed. That way, your home can have at least one "clean room" where you can spend time when allergy symptoms are acting up.
• Starting your medicine before allergy season starts: If you know that every fall, you'll be going to battle against ragweed, ask your doctor about starting your medication a couple of weeks before the pollen levels rise. That way, you can get ahead of your symptoms. And any you do have will be less severe.

Can you cure allergies?

There's no cure for allergies. But if your symptoms affect your quality of life, your doctor may suggest allergy shots (aka immunotherapy).

Immunotherapy gradually exposes you to more and more of a specific allergen. It's meant to "train" your body to tolerate allergens. Your first injections take place over a period of months. Then, they're followed by maintenance shots for several years.⁸

Immunotherapy is typically recommended only if:

• You're sensitive to several allergens, or
• You have severe or worsening symptoms

Not yet working with a healthcare professional for allergy treatment? Think about making an appointment with a healthcare professional and getting a referral to an allergy specialist.

Summary

With the right plan, you can learn to manage your allergy symptoms so they don't manage you.

Even if you think your allergy symptoms are no big deal, think about bringing them up with a doctor. A healthcare professional can help you identify allergens that might be causing your symptoms and offer guidance on how to treat symptoms.

If you think you're experiencing a severe allergic reaction, seek emergency care right away.