Dr. Greene’s Answer:
Many kids (including my daughter Claire) develop large local reactions to mosquito bites – charmingly called Skeeter Syndrome. It’s a reaction to proteins in mosquitos’ saliva. There’s usually some reaction within hours of the bite, which progresses over 8 to 12 hours or more, and then disappears within 3 to 10 days. The reactions can be quite dramatic, and occasionally even blister or bruise.
It’s rare to get any whole-body symptoms from this.
The most common age for it to start is somewhere between age 2 and age 4, and (good news!) once it develops, most kids only have this for several more summers before the reactions disappear. It takes a few extra years to go away for kids who live in Alaska, northern Canada and the Nordic countries.
In the meantime, the keys are preventing mosquito bites, and dealing with bites that do occur.
For prevention my favorite repellant is oil of lemon eucalyptus (like Repel Plant-Based Lemon Eucalyptus Natural Insect Repellent brand). It can be as effective as DEET, but only lasts 2-5 hours.
Natrapel 8 Hour is another DEET-free formula and uses picaridin as its active ingredient. Picaridin is a synthetic compound similar to that found in black pepper. Natrapel was the only DEET-free formula to make Consumer Report’s 2014 list of top five mosquito repellents.
Mosquitoes bite most at dawn and dusk and especially near wetlands or grass. Timing activities outdoors can make a big difference.
When your son is likely to be bitten, a non-sedating antihistamine like Claritin once a day, taken before the bite, can reduce reactions.
After the bite, an anti-itch cream containing hydrocortisone can have a good benefit-to-risk ratio if he is uncomfortable, or a stronger antihistamine like Benadryl (by mouth, not topically). There are stronger medicines if the bite happens to be in a spot that interferes with vision, eating, drinking, or walking.
These bites can get infected – but you won’t see swelling or redness from infection within hours of the bite, so only suspect this if it is not progressing on schedule or he has other symptoms. Most of these large reactions never require antibiotics.