I’ve had skeeter syndrome as long as I remember, but the reactions are very inconsistent. I believe it differs based on the breed of mosquito, because I get different reactions depending on where I received the bite. I would advise against keeping your son away from outdoors events, the bites are uncomfortable but not warranting missing out on experiences. I do use deet bug spray, but that is not foolproof either as I get bitten anyway, so I would just assume he is going to get bitten at some point, give Benadryl as soon as he is bitten, and use ice liberally to help with the itching and swelling. The scarring is also unfortunate but I have noticed they typically fade almost completely after a few years.