Parasite causing whole body itch? Please help.

I found a part of a GI system parasite. As the parasite sent to the lab was mislabelled and several stool samples failed to show anything, we ended up treating based on the pictures. Treatment was one time 500 mg Mebendazole (Vermox).

Shortly after taking the mebendazole, a chronic skin itch condition I had been enduring for many years improved. The itch was worst where there was pressure or rubbing from clothing, for example the waist.

I was overjoyed to have less itch; I was also sleeping much better. But after 2 months the itch seems to be coming back.

I have travelled to a variety of countries.

Could I still have the parasite despite taking the medication? Does mebendazole kill all likely intestinal parasites in the body, or just the ones in the GI system itself? I take it that these type of worms can migrate, might it be that those in other places were not killed by the mebendazole? What should I do? Any other thoughts or help would very much be appreciated.

I am contemplating getting some diatomaceous earth, food grade and taking a tablespoon type dose. Any thoughts? Side effects?

Thanks folks.