Why wait 20 minutes after an Allergy Shot?

An allergy shot typically causes a mild local reaction to the skin with redness and swelling at the injection site. However, a more severe reaction can also occur that may involve itching, hives, swelling of the throat, tightness in the chest and trouble breathing, and even a life-threatening drop in blood pressure. These severe reactions usually occur within the first 20–30 minutes, and our trained staff has emergency equipment on hand to stop this reaction.