I am thinking that some scabies mites are resistant to permethrin. It could be the only reason why, I had the same feeling when I first used permethrin, it would seem like it worked for a week but then things just come back the exact same like it only put them into hiding. Once I started using sulfur creams nightly things only got better and eventually went away. Kwellada p also made me feel sick almost for a few days and gave me this buzzing affect like I was a lightbulb turned on.