cortisone cream for itches? I think I got the wrong thing.

okay,
I could have added this to my last post, but it's kind of a new question on same topic.

So, my son's feet were super duper itchy last night- wake you up itchy.

I got some great advice on natural ways to help relieve the itch, so thanks to those people with the ideas; those are what I'll try first always.

but, it was so bad for him last night, that I thought I wanted a back-up in my medicine cabinet just in case he had another bad night and the natural remedies didn't cut it. (It was so hard to see him sad, frustrated, and itchy from 1-2 AM), so I went to get some Benadryl gel which was recommended to me by someone.
I thought I'll ask the pharmacist if that sounds good and he said to use a cortisone cream instead to prevent toxic build-up since he's on abx.

So, I bought a $3.00 tube of cortisone cream thinking I'll keep it around just in case the itches get out of control again.

Then I remembered I've read don't use cortisone creams with lyme, b/c of steroid? I don't want to do anything to slow down the healing for him.

So, what to do? I guess just hope the coconut oil and other natural ideas work if he itches again? (thank goodness tonight it didn't get bad with itches!)

is the benadryl bad with abx?

thanks in advance for ideas and input!

I have had reactions (angry red itchy rash across chest, neck) to antibiotics (levofloxacins) in the past, started taking them with a benedryl capsule, without any impact on the antibiotics. But not sure about child dosing.

-p