Allergy Shots: Worth the Wait

Q. Why do I have to wait 15 minutes after allergy shots at the doctor's office? I've never had an allergic reaction.

A. Waiting for 15 minutes after receiving an allergy shot is inconvenient, I know. But allergy shots contain what the individual is allergic to, so the major risk from an allergy shot is an allergic reaction.

Intuitively, you might think such reactions would be most likely to occur during the build-up phase of allergy shots - the initial period of about three to six months where the dose of allergen you receive is gradually increased - but it turns out that's not the case. Reactions can happen at any time, even long after a maintance dose has been achieved (that's when the shots get less frequent and keep up your immunity to the allergen).

While most reactions to allergy shots are mild, there is a small risk of a serious reaction. And rapid treatment is key in preventing mild reactions from progressing into more serious ones. The vast majority of allergy shot reactions occur within 15 minutes of the injection, but occasionally they happen later.

The professional allergy associations' joint recommendation is that to ensure safety, individuals should stay in the doctor's office for at least 15 minutes after receiving an allergy shot. Patients who have experienced reactions more than 15 minutes after an allergy shot should be observed for a longer period of time.

Source: White MD, Martha. Allergy & Asthma Today, Volume 9, Issue 4. Winter 2011.