General Allergic Reactions (Child)

An allergic reaction is a set of symptoms caused by an allergen. An allergen is something that causes your child's immune system to react abnormally. It releases various chemicals. These include histamine. Histamine causes swelling and itching. An allergic reaction may affect the entire body. This is called a general allergic reaction. But often symptoms affect only one part of the body. This is called a local allergic reaction.

Your child is having an allergic reaction. Almost anything can cause one. Different children are allergic to different things. It's usually something that your child ate or swallowed, came into contact with by getting or putting it on their skin or clothes, or something they breathed in the air. The immune system for some children is very sensitive. A child can have an allergic reaction to many things. 

Common allergy symptoms include:

  • Itching of the eyes, nose, and roof of the mouth

  • Runny or stuffy nose

  • Watery eyes 

  • Sneezing or coughing 

  • A blocked feeling in the ears

  • Red, raised itchy rash called hives

  • Rash, redness, welts, blisters

  • Itching, burning, stinging, pain

  • Dry, flaky, cracking, scaly skin

  • Red and purple spots

Severe symptoms include:

  • Nausea and vomiting

  • Diarrhea

  • Swelling of the face and mouth

  • Trouble breathing or gasping for breath

  • Lightheadedness, fainting, or dizziness

  • Cool, moist, pale skin

  • Fast but weak heartbeat

  • Feeling of doom

  • Stomach pain

If your child has severe symptoms, it is called anaphylaxis. This is a medical emergency.

An allergic reaction can be caused by many kinds of allergens. Common causes of local or mild to moderate allergic reactions are pollen, mold, mildew, animal dander, and dust. Severe allergic reactions can be caused by foods, medicines, natural rubber latex, and stinging insects, especially bees, wasps, hornets, and yellow jackets. Mild symptoms often go away by using antihistamines or steroids. In some cases, pain medicine can help ease symptoms. But a child with a severe allergic reaction needs medical attention right away.

Home care

Woman giving liquid medication to boy.

The healthcare provider may prescribe medicines to relieve swelling, itching, and pain. Follow all instructions when giving these medicines to your child. If your child had a severe reaction, the provider may prescribe an epinephrine auto-injector kit. Epinephrine will help stop a severe allergic reaction. Make sure that you understand when and how to use this medicine.

General care

  • Make sure your child does not scratch areas of his or her body that had a reaction. This will help prevent infection.

  • Help your child stay away from air pollution, tobacco and wood smoke, and cold temperatures. These can make allergy symptoms worse.

  • Try to find out what caused your child’s allergic reaction. Make sure to remove the allergen. Future reactions may be the same or might be worse.

  • If your child has a serious allergy, have him or her wear a medical alert bracelet that notes this allergy. Or, carry a medical alert card for your baby.

  • If the healthcare provider prescribes an epinephrine auto-injector kit, keep it with your child at all times.

  • Tell all care providers and school officials about your child’s allergy. Tell them how to use any prescribed medicine.

  • Keep a record of allergies and symptoms, and when they occurred. This will help your provider treat your child over time.

Follow-up care

Follow up with your child’s healthcare provider. Your child may need to see an allergist. An allergist can help find the cause of an allergic reaction and give recommendations on how to prevent future reactions.

Call 911

Call 911 if any of these occur:

  • Trouble breathing, talking, or swallowing

  • Any change in level of alertness or unconsciousness

  • Cool, moist, or pale (or blue in color) skin 

  • Fast or weak heartbeat

  • Wheezing or feeling short of breath

  • Feeling lightheaded or confused

  • Very drowsy or trouble awakening

  • Swelling of the tongue, face, or lips

  • Drooling

  • Severe nausea or vomiting

  • Diarrhea

  • Seizure

  • Feeling of dizziness or weakness or a sudden drop in blood pressure

When to seek medical advice

Call your child's healthcare provider or get medical care right away if any of these occur:

  • Hives or a rash

  • Spreading areas of itching, redness, or swelling

  • Fever (see fever section below)

  • Symptoms don’t go away, or come back

  • Fluid or colored drainage from the affected site

Fever and children

Use a digital thermometer to check your child’s temperature. Don't use a mercury thermometer. There are different kinds of digital thermometers. They include ones for the mouth, ear, forehead (temporal), rectum, or armpit. Ear temperatures aren’t accurate before 6 months of age. Don’t take an oral temperature until your child is at least 4 years old.

Use a rectal thermometer with care. It may accidentally poke a hole in the rectum. It may pass on germs from the stool. Follow the product maker’s directions for correct use. If you don’t feel OK using a rectal thermometer, use another type. When you talk to your child’s healthcare provider, tell him or her which type you used.

Below are guidelines to know if your child has a fever. Your child's healthcare provider may give you different numbers for your child.

A baby under 3 months old:

  • First, ask your child’s healthcare provider how you should take the temperature.

  • Rectal or forehead: 100.4°F (38°C) or higher

  • Armpit: 99°F (37.2°C) or higher

A child age 3 months to 36 months (3 years):

  • Rectal, forehead, or ear: 102°F (38.9°C) or higher

  • Armpit: 101°F (38.3°C) or higher

Call the healthcare provider in these cases:

  • Repeated temperature of 104°F (40°C) or higher

  • Fever that lasts more than 24 hours in a child under age 2

  • Fever that lasts for 3 days in a child age 2 or older

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