What can you use to treat itching and swelling of tick bites?

Ointment/Benadryl. For localized itching and swelling Benadryl (diphenhydramine 25 mg) can be used, or application of 1% Hydrocortisone ointment.
Itchies Away. Apply over the counter Hydrocortisone 1% cream or calamine lotion. You can take other the counter antihistamines like Diphenhydramine [benadryl] or chorpheniramine maleate [chlortrimeton]. If these make you too sleepy, you can take non-drowsy Loratadine [claritin, alavert] instead.