Allergy facts for kids

Quick facts for kids Allergy
Hives are a common allergic symptom
Symptoms	Red eyes, itchy rash, runny nose, shortness of breath, swelling, sneezing
Types	Hay fever, food allergies, atopic dermatitis, allergic asthma, anaphylaxis
Causes	Genetic and environmental factors
Diagnostic method	Based on symptoms, skin prick test, blood test
Similar conditions	Food intolerances, food poisoning
Prevention	Early exposure to potential allergens
Treatment	Avoiding known allergens, medications, allergen immunotherapy
Medication	Steroids, antihistamines, epinephrine, mast cell stabilizers, antileukotrienes
Frequency	Common

Allergies happen when your body's immune system reacts strongly to things that are usually harmless. These things are called allergens. The word "allergy" was first used in 1906.

Allergies can cause different problems. Some common types are hay fever, food allergies, and allergic asthma. A very serious reaction is called anaphylaxis.

Symptoms can include red eyes, an itchy rash, sneezing, or a runny nose. You might also feel shortness of breath or see swelling. It's important to know that allergies are different from food intolerances or food poisoning.

Common allergens include pollen and certain foods. Metals and other things can also cause reactions. Severe reactions often come from food, insect stings, or medicines. Your genes and the environment around you can both play a part in developing allergies.

Doctors usually figure out if you have an allergy by asking about your medical history. They might also do skin or blood tests. But a positive test doesn't always mean you have a serious allergy to that substance.

If someone has a very bad allergic reaction, they might need a shot of epinephrine. This medicine helps reduce swelling. For some allergies, like hay fever or insect stings, doctors can use allergen immunotherapy. This treatment slowly exposes you to tiny amounts of the allergen.

Allergies are very common. In many developed countries, about 1 in 5 people get hay fever. Around 6% of people have at least one food allergy. Also, about 1 in 5 people will have dermatitis at some point. The number of people with allergies seems to be growing, especially in cities and industrialized areas.

What Happens During an Allergic Reaction?

Swelling of the hand from an allergic reaction

When you touch or breathe in something you're allergic to, your body can react in many ways. Your eyes might get very itchy, or your nose might run or get stuffy. You might start to cough and sneeze a lot.

Sometimes, a rash called hives can appear on your skin. Your face might also swell up. If it's a food allergy, you could get a stomach ache.

What is Anaphylaxis?

Sometimes, a person's throat can swell so much that it becomes hard to breathe. This very serious reaction is called anaphylaxis. If this happens, a doctor must give the person epinephrine right away to make the swelling go down. About 0.05% to 2% of people experience anaphylaxis. Some people who are very allergic to things like bee stings carry epinephrine with them for emergencies.

Many allergens, like dust or pollen, float in the air. When you breathe them in, symptoms often appear in parts of your body that touch the air. This includes your eyes, nose, and lungs. For example, hay fever causes your nose to get irritated, making you sneeze and itch. It can also make your eyes red. Allergens you breathe in can also cause your lungs to make more mucus. This can lead to shortness of breath, coughing, and wheezing.

Common Allergy Signs and Symptoms

What Causes Allergies?

There are two main reasons why someone might get allergies: things about their body and things in their environment. Your genes, sex, and age can play a role. However, allergies are becoming more common, and this can't be explained by genes alone.

Some environmental factors that might cause more allergies include:

• Changes in how much we are exposed to germs when we are very young.
• Pollution in the air.
• How much allergen is in the environment.
• Changes in our diet.

Common Allergens

An allergy testing machine being operated in a lab

Shelves in a pharmacy with anti-allergy products

Here are some common foods that people are allergic to:

• Nuts, especially peanuts
• Fish or shellfish
• Dairy products
• Eggs
• Soy products
• Wheat
• Fruits like kiwis and bananas

Here are some common things in the environment that cause allergies:

• Latex
• Pollen
• Ragweed
• Mold
• Pet fur
• Bee or wasp stings
• Dust mites
• Tobacco smoke
• Pollution

Allergic reactions can also happen from insect stings and reactions to medications like aspirin and antibiotics such as penicillin.

If you have a food allergy, you might get abdominal pain, bloating, vomiting, or diarrhea. Your skin might also get itchy, or you could have swelling with hives. Food allergies rarely cause breathing problems or a runny nose.

Insect stings, certain foods, and some medicines can cause a severe allergic reaction called anaphylaxis. This can affect many parts of your body, like your digestive system, your respiratory system, and your circulatory system. Depending on how serious it is, anaphylaxis can cause skin reactions, trouble breathing, swelling, low blood pressure, and can even be life-threatening.

This type of reaction can start very quickly, or it might be delayed. Sometimes, the reaction might seem to get better, but it can still be happening inside your body for a while.

Images for kids

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  A summary diagram that explains how allergy develops

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  Tissues affected in allergic inflammation

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  Skin testing on arm

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  Skin testing on back

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  Patch test

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  Anti-allergy immunotherapy

See also

In Spanish: Alergia para niños