What causes allergic reactions?

Allergic reactions are caused by overactivity of the immune system against specific foreign substances called antigens. Reactions can be mild, such as rashes, to a severe, life-threatening condition called anaphylaxis (anaphylactic shock).

Common antigens that often cause allergic reactions in at-risk people include:
  • Bee or insect venom
  • Antibiotics
  • Pollen
  • Animal dander
  • Latex
  • Sulfa drugs
  • Certain foods, such as tree nuts, peanuts, shellfish, strawberries, and coconut oil

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.