Allergic reaction to Mosquito bite?

My 15 month old got bitten by a mosquito last night. My fiancé (his dad) Mom said that this used to happen to him all the time but I mean this is not normal I feel like? My bites are very small and normal looking. In person it’s probably about 1-2 inches wide. My mom who’s an RN said some person are just sensitive to it, but I still worry a lot. Is there anything I can do to put on it that makes it heal faster? He got bit on the back a couple weeks ago and I’m pretty sure it’s scared.