What to Do When You Have an Allergic Reaction

Answers to 7 common questions

What to Do When You Have an Allergic Reaction

Pollen, dust, animal dander, nuts, shellfish and other foods — these can all cause an allergic reaction in susceptible people.

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The symptoms range from being mildly uncomfortable and annoying to serious and life-threatening. So it’s good to know what to do if you or someone you’re with has an allergic reaction.

You may need to act quickly.

Here, allergist and immunologist Bela Faltay, MD, answers common questions about allergic reactions and how to handle them:

1. What happens during an allergic reaction?

When you eat, breathe in or touch something you’re allergic to, your immune system produces histamines to deal with the bothersome substance (allergen).

This immune response can cause several symptoms, including:

  • Itching
  • A rash
  • Hives (large, pink bumps or swollen areas)
  • Sneezing and watery eyes
  • Swelling in the mouth or throat
  • Rapid or difficult breathing

2. What should you do for throat swelling and difficulty breathing?

Call 911 immediately for medical help. Sometimes severe allergic reactions that cause you to struggle for breath can also create a sense of impending doom, says Dr. Faltay.

If the person who’s having an allergic reaction stops talking and simply stares, that’s a red flag as well.

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“Calling 911 is better than driving to the emergency department,” he says. “Emergency medical technicians in an ambulance have protocols and access to treatments specifically for severe allergic reactions.”

3. What can you do to relieve itching, redness or a rash?

Wash the area with mild soap and lukewarm water. Apply hydrocortisone cream or lotion. Calamine lotion and cool compresses may also bring relief.

If you know what’s causing the reaction, stop using the product or wearing the item. Take off makeup or earrings if they’re the cause.

If you’re allergic to poison ivy, sumac or oak and have been exposed, wash clothing and other items that may have the irritant (an oily sap called urushiol) on them.

If your itchiness is severe, if your rash doesn’t go away, or if you see signs of infection, call your doctor.

4. What’s the best way to treat itching, sneezing and watery eyes?

When you have multiple allergic symptoms, an over-the-counter antihistamine such as loratadine (Claritin®) can treat them.

Dr. Faltay advises against using products that have a sedative effect, such as Benedryl®.

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5. What should you do when hives develop?

The hives will subside in time. Meanwhile, it helps to apply cool compresses, to avoid hot showers and bath water, to wear loose clothing and to sleep in a cool room.

Be sure to work with your doctor to identify what’s triggering your hives.

6. Can allergies occur unexpectedly?

Yes. It’s important to know that some allergies are linked to others.

For example, if you’re allergic to latex, it’s possible that you’ll also react to avocados, kiwifruit and other tropical fruit. And if you’re allergic to birch pollen, it’s possible that you’ll react to apples or peaches as well.

It’s important to note that what seems like a food allergy can sometimes be food intolerance instead, notes Dr. Faltay.

7. What if you don’t know what’s causing your reaction?

Follow up with your doctor and ask about allergy testing, he advises. Testing can help pinpoint the cause of your reaction, and help you avoid triggers and future reactions.

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