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Symptoms of a severe allergic reaction (Anaphylaxis) can start within minutes of eating or exposure to an allergen (a substance capable of causing an allergic reaction). In fewer cases, the reaction can take up to several hours after exposure.
Symptoms of a severe allergic reaction can vary from person to person. The same person can have different symptoms each time they have a severe allergic reaction. A severe reaction can take place without hives, so make sure to look out for all signs of an allergic reaction. Do not ignore early symptoms. When a reaction begins, it is important to respond right away. To learn more about severe allergic reactions and the proper emergency management, visit our Severe allergic reaction (Anaphylaxis) health feature.
Current as of: February 10, 2021
Author: Healthwise Staff
Medical Review:E. Gregory Thompson MD - Internal Medicine & Brian D. O'Brien MD - Internal Medicine & Adam Husney MD - Family Medicine & Martin J. Gabica MD - Family Medicine & Kathleen Romito MD - Family Medicine & Rohit K Katial MD - Allergy and Immunology & Martin J. Gabica MD - Family Medicine