What is the best way to treat a lot of flea bites on toddlers?

Hydrocortisone cream: If you are allergic to the bites, then they will itch for weeks. If you scratch them, they will itch until you quit scratching them. They can cause hard bumps called nodules if you continue to rub or scratch. Also, kill the fleas in the house, yard, pets. Other bites can look like flea bites such as scabies and other mites. Hydrocortisone cream and oral Benadryl (diphenhydramine) will help the itch.

Get rid of the fleas: Themselves. Use antiseptic soap to wash the flea bites. Do not scratch flea bites. You can use 1% Hydrocortisone cream on the bites or take antihistamines for itching. A paste made of 2 parts baking soda ; 1 part water can be applied to bites. The bigger issue is that you must get rid of the fleas. Many people elect to hire an exterminator.