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Allergic Reactions (Limited to Severe)

Limited reaction

Most people will have a limited (localized) reaction that affects the area of contact exposed to an allergen (triggers an allergic reaction). Some people may develop "local" swelling that can be excessive or extreme. After exposure to an allergen, swelling may occur almost immediately or it may not show up for an hour or two. Remember, your first reaction to an allergen may be mild, but future reactions can become severe, even life-threatening.

Allergens can be breathed in (inhaled), eaten (food), or injected (by insects, medicine) in the body. Allergies can be hereditary. Some common allergies include:

  • Pollen: Tree, grass, weed

  • Mold: Inside and outside

  • Dust mites

  • Cockroaches

  • Animal dander: Cats, dogs, horses, rabbits

  • Food: Eggs, peanuts, cow's milk, nuts, soy, fish, wheat, peas, shellfish

  • Drugs: Penicillin, aspirin, non-steroidal anti-inflammatory (NSAIDs), anesthesia

  • Insect stings and bites: Yellow jackets, wasps, bees, hornets, fire ants

  • Contact: Latex, poison ivy, poison oak, detergents, cleansers, chemicals

General care

Prevention (avoiding allergens)

  • To help prevent stings or bites, during active insect season (late summer and early fall) remember to avoid:

    • Walking barefoot in grass (wear shoes outside)

    • Wearing sweet smelling fragrances (perfumes, hairsprays, lotions)

    • Wearing bright colored clothes, especially flowery patterns

  • Pollen: Keep windows closed during pollen season

  • Mold and dust mites: Keep your home clean and dry

  • Animal dander: Avoid living with pets

  • Food: Do not eat the food again. Read all food ingredient labels very carefully. Ask how food is prepared at restaurants.

  • Drugs: Do not take the medication again. Tell your health care provider about your reaction and the name of the medication.


  • Wash the skin with soap and cool water immediately

  • Remove clothing that may have plan oils (or other substances that has caused a reaction) and wash in hot water. Use rubbing alcohol to clean your shoes if they were exposed to the allergen. Shower with plenty of soap to wash remaining plain oils (or other allergens) off the skin.

  • calamine lotion and Burrow's solution can help ease the itching.

  • Always contact your doctor before starting over-the-counter medications such as antihistamines, decongestants, cromolyn, and corticosteroids (nasal spray, topical)

  • Contact your health care provider if:

    • Rash is near your eyes or covering a large portion  of your body

    • Itching gets worse (can't stop itching)

Severe reaction

Anaphylaxis is a severe reaction that affects more than one organ including the skin, respiratory system, cardiovascular system, or digestive tract. The reaction may be immediate or develop over several hours after exposure to an allergen. 

Symptoms can range from mild to severe. They can come in any combination. Some can quickly become life-threatening.

Anaphylaxis is likely if two or more of the following symptoms occur within minutes to several hours after exposure:

  • Hives, itchiness, or redness all over the body and swelling of the lips, tongue, or back of the throat

  • Trouble breathing

  • Tightness of the throat or a hoarse voice

  • Severe gastrointestinal symptoms such as abdominal cramps or pain, diarrhea, nausea, or vomiting

  • Dizziness or fainting (signs of a drop in blood pressure)

  • Increased (rapid) heart beat

If you have symptoms of anaphylaxis, and you have an auto-injector of epinephrine, use it immediately and call 911. If you don't have an auto-injector, call 911. Lie down with your feet above the level of your heart.

Be S.A.F.E. Action Guide

Physicians (allergists and emergency department) have joined to develop a Be S.A.F.E. Action Guide. Click on this link to learn more about the Be S.A.F.E.

Online Medical Reviewer: Godsey, Cynthia, MSN, APRN, MSHE, FNP-BC
Online Medical Reviewer: Pierce-Smith, Daphne, RN, MSN, CCRC
Date Last Reviewed: 1/30/2015
© 2000-2014 The StayWell Company, LLC. 780 Township Line Road, Yardley, PA 19067. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.
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