Pinworm external eradication?

I am on my 2nd full round of ParaGone(I did 4 weeks a few months ago)in an attempt to alleviate anal itching. It definitely helped the first time. It's been recommended to changed bedsheets every day, instead I wear underwear to bed and put all underwear in a ziplock bag and wash every few days. Is there anything topically(on the anal area) I could use if indeed pinworms in the problem?

Nancy