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Why Do You Have Allergies All of a Sudden?

Is It an Allergy?

An allergy might not be causing your problem. Irritants that can cause allergy-like symptoms include perfumes, sprays, tobacco smoke, and traffic fumes. Medications and conditions, including pregnancy, can also bring on symptoms. 

This is called "non-allergic rhinitis." It’s not an allergy itself, but irritants may make non-allergic rhinitis symptoms worse.

Treating Adult Allergies

If you have mild symptoms, over-the-counter antihistamines may offer relief. But it’s best to see a doctor to find out what's causing the reaction, so you get the right treatment. 

For example, antihistamines might not help symptoms triggered by an irritant. And if a sudden reaction to certain foods is linked to a pollen allergy, your allergist will need to treat the pollen allergy.

Allergies are treated three ways:

  • avoiding the allergen
  • taking medication such as an antihistamine, decongestant, or steroid pills or sprays, creams, or ointments
  • getting allergy shots to change how your immune system responds to the allergen 
    • Usually, the shots are given only if the other two treatments don’t bring enough relief.

Some signs of a severe reaction are:

  • hives
  • dizziness
  • sweating
  • trouble breathing or swallowing

If you think you may be having a severe reaction, call 911.

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Reviewed on April 10, 2014

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