We compile and answer the most frequently searched queries regarding allergy symptoms, testing, treatments, and daily management. For detailed clinical information, follow the links to our dedicated guides below. Our allergy vs. intolerance guide answers one of the most common patient confusions, while our diagnosis timeline explains exactly what to expect from your allergist visit.
Medical Authority Guide
Frequently Asked Questions About Allergies
Expert, evidence-based answers to the most common allergy inquiries.
SJ
Medically reviewed by Dr. Sarah Jenkins, MD, FACAAI
Verified ReviewerBoard Certified Allergist & Immunologist · Clinical Allergy, Asthma & Immunology
Stanford University School of Medicine
Updated March 2026·Annual review cycle
Our editorial process: All content on WhatAreAllergies.com is written by medical writers and reviewed by board-certified allergists and immunologists. We follow ACAAI, AAAAI, WAO, and ARIA clinical guidelines. Content is updated on an annual review cycle or when major guidelines change. We do not accept advertising influence on editorial content. Read our editorial policy →
Continue Reading
Frequently Asked Questions
What is the difference between an allergy and an intolerance?
An allergy involves an immune system reaction (IgE antibodies), can be life-threatening, and symptoms occur even with tiny exposures. A food intolerance (e.g., lactose intolerance) is a digestive system issue, is not life-threatening, and is often dose-dependent. See our full guide: Allergy vs Food Intolerance.
Can allergies develop at any age?
Yes. While many allergies develop in childhood, adult-onset allergies are increasingly common. Immune system changes, new environmental exposures, or shifts in microbiome can trigger sensitization at any stage of life.
How long does allergy testing take?
A skin prick test produces results in 15-20 minutes. A blood (specific IgE) test takes 1-7 business days for lab results. An elimination diet protocol typically runs 2-8 weeks. See our Allergy Diagnosis Timeline for the full clinical pathway.
Is immunotherapy a cure for allergies?
Allergen immunotherapy can induce long-term tolerance that persists after treatment ends — particularly for environmental allergies. For food allergies, oral immunotherapy raises the reaction threshold but requires ongoing maintenance dosing. It is the closest treatment to a cure currently available.
What should I do if I think I am having anaphylaxis?
Administer epinephrine (EpiPen) immediately into the outer mid-thigh, then call 911. Do not wait to see if symptoms improve on their own. Antihistamines alone cannot reverse anaphylaxis. Read our Anaphylaxis Emergency Guide for full protocol.
Related Allergy Guides
Medically reviewed guides recommended for you
About the Medical Team
SJ
Medical Review
Dr. Sarah Jenkins, MD, FACAAI
Board Certified Allergist & Immunologist
Clinical Allergy, Asthma & Immunology
Stanford University School of Medicine
MC
Written by
Dr. Michael Chen, MD, PhD
Clinical Immunologist & Researcher
Translational Immunology, Biologic Therapies
Johns Hopkins University
All contributors hold active board certification in allergy, immunology, or a related specialty. View full credentials →
Medical References & Citations
- 1guideline2006
Sampson HA, et al. "Second symposium on the definition and management of anaphylaxis: Summary report" — Journal of Allergy and Clinical Immunology.
View source - 2database2025
American College of Allergy, Asthma & Immunology (ACAAI) "Allergy Facts and Figures" — ACAAI Clinical Resources.
View source - 3review2025
World Allergy Organization (WAO) "White Book on Allergy — 2025 Update" — World Allergy Organization.
View source - 4guideline2024
National Institute of Allergy and Infectious Diseases (NIAID) "Clinical Guidelines for the Diagnosis and Management of Food Allergy" — National Institutes of Health.
View source - 5guideline2024
Muraro A, et al. "EAACI food allergy and anaphylaxis guidelines: Diagnosis and management of food allergy" — Allergy — European Journal of Allergy and Clinical Immunology.
This content reflects clinical guidelines current as of the last review date shown above. Always consult a qualified healthcare provider for personalized medical advice.