R.F.
ONLY because with my personal experience with delayed allergic reactions to ant bites, I would call your pediatrician. Benedryl and OTC hydrocortisone cream will help, but there might be a prescription that can prevent a more serious reaction, plus relieve any discomfort since it's so widespread. Even if your dr. recommends OTC meds, you'll at least get the proper dosage since he's under 2. Good luck!