Anaphylaxis is a more serious medical condition because of its suddenness. In most cases, it is an acute type I anaphylactic reaction that occurs rapidly within a short period of time, such as one minute, a few minutes or ten minutes. The timing of anaphylaxis varies from person to person and is not absolute. It is related to each person’s physical state, age and constitution, as well as the amount of allergens that he or she has been exposed to and the amount of allergens that have entered the body. If the amount of allergen is large, the time to anaphylaxis will be very short.