Well, I don't necessarily feel a night time itch, mine is all day and better at night because I shower right before bed.
I only suggested Candida because it can feel somewhat similiar. Also Candida, when it comes out, it can come out in strands that can seem like worms but is actually Candida Strands and it itches like crazy and much more at night.
I am not saying that's what you have, just a possibility. Have you had any yeast problems? Vaginal, thrush in the mouth or rash on the foot?
You have done so much to get rid of these pinworms, it seems like they should of gone by now but obviosly they are very resistant.
Pinworm would be the easiest things to diagnose with a doctor as for other types of worms, so hard to get them to show up in stool samples and blood tests.
No matter what it is, taking Oregano Oil is very helpful. That stuff is VERY powerful. I had to stop taking it because it was too strong and it was making the worms wiggle and jump everywhere, just like the humaworm did. It is also great for many other problems, such as candida.