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Children's Hospital at Dartmouth Hitchcock (CHad)
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About allergic reactions

  • Allergens only cause reactions in people who are allergic to them. Allergic reactions depend on specific responses by the immune system to things in the environment.
  • In high-risk patients, avoidance of certain things that tend to cause these reactions can sometimes help prevent them. Once an allergy starts, avoidance is a mainstay of therapy.
  • Most people with allergies tend to inherit them from one or both parents.
  • Although allergies may only be noticed later in life, they usually begin during childhood.

How we make contact with allergens

  • Inhaled through the nose and lungs (pollens, house dust, and animal danders)
  • Ingested or taken in by mouth (foods, drinks, and medications)
  • Contacted by the skin (dust, animal dander, and even foods)
  • Injected through the skin (insect stings and injected medications)

Common symptoms of allergies

  • Sneezing
  • Itching
  • Dripping
  • Swelling
  • Coughing
  • Wheezing
  • Vomiting

Common allergic conditions

  • Allergic rhinitis
  • Anaphylaxis
  • Atopic dermatitis
  • Childhood asthma and wheezing
  • Eosinophilic esophagitis
  • Food allergies
  • Hereditary and acquired angioedema
  • Hives
  • Immunodeficiencies and recurrent infections
  • Latex allergy
  • Pollen, animal dander, mold and mite allergies
  • Reactions to stinging insects
  • Suspected allergic reactions to drugs
  • Urticaria
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