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Allergic Reaction

Allergic Reaction

What Causes an Allergic Reaction?

Allergies appear to run in families, which means they can be inherited. If you have a close family member who has allergies, you’re at greater risk of developing them.

The reasons why allergies develop are unclear, but some substances are known to commonly cause an allergic reaction. People who have allergies are typically allergic to one or more of the following:

Pet dander, such as the kind from a cat or dog

Bee stings or bites from other insects

Certain foods, including nuts and shellfish

Certain medications, such as penicillin and aspirin

Certain plants



Dust mites

What are the Symptoms of an Allergic Reaction?

The symptoms of an allergic reaction can vary from mild to severe. If you become exposed to an allergen for the first time, your symptoms may be mild. These symptoms may get worse if you repeatedly come into contact with the allergen.

Mild to Moderate Reaction

Symptoms of a mild to moderate allergic reaction can include:

Hives, or itchy red spots on the skin



Allergic rhinitis, which may lead to symptoms such as nasal congestion or sneezing

Scratchy throat

Watery or itchy eyes




  • Baby Allergic Reaction to Food: Signs and Symptoms





If you experience an allergic reaction and you don’t know what’s causing it, you may need to see a doctor to determine which substances you’re allergic to.

If you have a known allergy and experience symptoms, you may not need to seek medical care if your symptoms are mild.

In most cases, over-the-counter antihistamines can be effective in controlling mild allergic reactions.

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