Why and I experiencing itchy skin?

For the last 2 months or so I have been having very itchy skin. It seems like it started after some muscle twitches started on my upper lip (I know that sounds weird). It started with me hands and feet, and now I itch almost all over if I don't take an antihistamine. My eyes and face even itch sometimes. Doctors have done blood work which all came back normal. Could it be my nerves causing both the twitching and the itching? Seems like it mostly happens at night or in the evening, but it sometimes even happens during the day. My doctor did tell me that I have lots of drainage and very red and swollen sinuses. Could this all be allergies maybe?