Why does my child get so swollen after a wasp bite? Is it anaphylaxis? Does it get worse every time? 5 to 12 years?

What the evidence says

When a wasp stings your child, their body releases chemicals that cause swelling, redness, and pain right where the sting happened. In some kids this local swelling gets quite large, sometimes covering a whole arm or leg. Doctors call this a 'large local reaction.' It's driven by the immune system but stays close to the sting site, and it's different from anaphylaxis, a whole-body allergic emergency.

A large local reaction usually keeps growing for one to two days after the sting, then slowly fades over about three to ten days. It can look alarming, especially in young children, but it isn't the same as a severe allergic reaction.

Anaphylaxis is different. It involves symptoms beyond the sting site, such as hives all over the body, swelling of the lips or throat, trouble breathing, vomiting, or feeling faint. This is a medical emergency needing epinephrine and a 911 call, not something to manage at home.

As for whether it gets worse every time, the honest answer is usually no for local swelling. Children who have had repeated large local reactions have a low chance of ever developing a true systemic or anaphylactic reaction to a future sting, and some studies found almost no risk at all in kids with a pattern of only local swelling. Guidelines say large local reactions alone don't mean your child needs to carry an epinephrine auto-injector or see an allergist for venom shots.

At home, cold compresses, raising the swollen limb, and an age-appropriate antihistamine or pain reliever can help with comfort. If the swelling is unusually large, keeps spreading well past the sting itself, or your child has any signs of a whole-body reaction, check in with a doctor to be sure what type of reaction this is.