Reation to an insect bite?

My son is alergic to mosquitos. When he gets bit, the subsequent day it swells up to the size of a baseball. He go to visit his grandparents this week and said he get biten by a horse fly the next afternoon his face swelled up so discouraging he looked like a differant kid. he get a rash adjectives over his chest and back. could a horse fly or deer fly mete out that? there be no mark or swelling where on earth he said he got bit. he be swimming alot and got sunburn where on earth the bite was. no food allergies and no topical detergents used. any info or sugestions will helpReation to an insect bite?
My daughter used to swell up surrounded by the face when she be little when mosquitoes bit her on her face. Definitely an allergic recoil but she seemed to grow out of it. What I found is a miracle when it comes to insect bites is TEA TREE OIL. If one is bitten, you apply it straight on the site and it almost instantly relieves pain, itching, unwary and soothes the bite. You can use it for ant, bullant, mosquitoe, European wasp, caterpillar, March flies, sand flies, flea etc. If he has trouble breathing after a bite, emphatically get him to medical sustain.
Medical Care.
Make sure he takes benedryl. It sounds approaching a reaction to something.