Allergy

Summary

An allergy is a reaction by your immune system to something that does not bother most other people. People who have allergies often are sensitive to more than one thing. Substances that often cause reactions are:

• Pollen
• Dust mites
• Mold spores
• Pet dander
• Food
• Insect stings
• Medicines

Normally, your immune system fights germs. It is your body’s defense system. In most allergic reactions, however, it is responding to a false alarm. Genes and the environment probably both play a role.

Allergies can cause a variety of symptoms such as a runny nose, sneezing, itching, rashes, swelling, or asthma. Allergies can range from minor to severe. Anaphylaxis is a severe reaction that can be life-threatening. Doctors use skin and blood tests to diagnose allergies. Treatments include medicines, allergy shots, and avoiding the substances that cause the reactions.

National Institute of Allergy and Infectious Diseases

Treatments and Therapies

• 6 Things To Know About Complementary Health Approaches for Seasonal Allergy Relief National Center for Complementary and Integrative Health
• Allergy Medications: Know Your Options Mayo Foundation for Medical Education and Research
• Allergy Shots: Could They Help Your Allergies? American Academy of Family Physicians
• Butterbur National Center for Complementary and Integrative Health
• Decongestants: OTC Relief for Congestion American Academy of Family Physicians
• Nasal Wash Treatment National Jewish Health

Children

• All about Allergies (For Parents) Nemours Foundation
• Allergy Relief for Your Child Food and Drug Administration
• Do Allergies Cause Asthma? Nemours Foundation
• Learning about Allergies Nemours Foundation
• Prevention of Allergies and Asthma in Children American Academy of Allergy, Asthma, and Immunology
• What Is a Pediatric Allergist / Immunologist? American Academy of Pediatrics

Diagnosis and Tests

• All About Allergy Testing American Academy of Allergy, Asthma, and Immunology
• Allergy Blood Test National Library of Medicine
• Allergy Skin Test National Library of Medicine

Prevention and Risk Factors

• Allergens and Irritants National Institute of Environmental Health Sciences
• Allergy-Proof Your House Mayo Foundation for Medical Education and Research

Genetics

• Allergic asthma: MedlinePlus Genetics National Library of Medicine
• Vibratory urticaria: MedlinePlus Genetics National Library of Medicine

Related Issues

• Allergic Bronchopulmonary Aspergillosis (ABPA) American Academy of Allergy, Asthma, and Immunology
• Allergies and Asthma: They Often Occur Together Mayo Foundation for Medical Education and Research
• Colds, Allergies and Sinusitis – How to Tell the Difference American Academy of Allergy, Asthma, and Immunology
• Eosinophilic Esophagitis: MedlinePlus Health Topic National Library of Medicine
• Feel Better. Live Better. See an Allergist / Immunologist American Academy of Allergy, Asthma, and Immunology
• Is It Flu, COVID-19, Allergies, or a Cold? National Institutes of Health
• Marvels of Mucus and Phlegm: The Slime That Keeps You Healthy National Institutes of Health

Encyclopedia

• Allergic conjunctivitis Medical Encyclopedia
• Allergic rhinitis – what to ask your doctor – adult Medical Encyclopedia
• Allergic rhinitis – what to ask your doctor – child Medical Encyclopedia
• Allergies, asthma, and pollen Medical Encyclopedia
• Allergy shots Medical Encyclopedia
• Erythema multiforme Medical Encyclopedia
• Hypersensitivity vasculitis Medical Encyclopedia
• Nasal corticosteroid sprays Medical Encyclopedia
• Saline nasal washes Medical Encyclopedia
• Sneezing Medical Encyclopedia
• Stuffy or runny nose – adult Medical Encyclopedia
• Stuffy or runny nose – children Medical Encyclopedia

Start Here

• Allergic Reactions American Academy of Allergy, Asthma, and Immunology

Patient Handouts

• Allergic reactions Medical Encyclopedia
• Allergic rhinitis – self-care Medical Encyclopedia
• Allergies Medical Encyclopedia
• Allergies, asthma, and dust Medical Encyclopedia
• Allergies, asthma, and molds Medical Encyclopedia
• Allergy testing – skin Medical Encyclopedia
• Angioedema Medical Encyclopedia
• Antihistamines for allergies Medical Encyclopedia

Specifics

• Allergic Skin Conditions American Academy of Allergy, Asthma, and Immunology
• Cockroach Allergy Asthma and Allergy Foundation of America
• Dust Mite Allergy Mayo Foundation for Medical Education and Research
• Mold Allergy Asthma and Allergy Foundation of America
• Nickel Allergy Mayo Foundation for Medical Education and Research
• Oral Hypersensitivity Reactions American Association of Oral and Maxillofacial Surgeons
• Pet Allergy Mayo Foundation for Medical Education and Research
• Physical Allergy Merck & Co., Inc.
• Stinging Insect Allergy American Academy of Allergy, Asthma, and Immunology
• Sun Allergy Mayo Foundation for Medical Education and Research

Teenagers

• Allergies Nemours Foundation
• Do Allergies Cause Asthma? Nemours Foundation

Videos and Tutorials

• Allergies Medical Encyclopedia
• Histamine: The Stuff Allergies are Made of National Library of Medicine

Find an Expert

• American Academy of Allergy, Asthma, and Immunology American Academy of Allergy, Asthma, and Immunology
• Find an Allergist/Immunologist American Academy of Allergy, Asthma, and Immunology
• National Institute of Allergy and Infectious Diseases National Institute of Allergy and Infectious Diseases
• National Institute of Environmental Health Sciences National Institute of Environmental Health Sciences

Clinical Trials

• ClinicalTrials.gov: Hypersensitivity National Institutes of Health
• ClinicalTrials.gov: Rhinitis, Allergic, Perennial National Institutes of Health

Statistics and Research

• FastStats: Allergies and Hay Fever National Center for Health Statistics
• Prevalence of Allergies the Same, Regardless of Where You Live National Institute of Environmental Health Sciences
• Seasonal Allergies at a Glance: What the Science Says National Center for Complementary and Integrative Health

Reference Desk

• Overview of the Immune System National Institute of Allergy and Infectious Diseases

Games

• Pet Allergy Quiz American Academy of Allergy, Asthma, and Immunology

Journal Articles

• Allergy

NIH MedlinePlus Magazine

• What Triggers Seasonal Allergies?