Barely visible tiny red marks.. wake up in the middle of the night... itching lower arms and lower legs like crazy!

It could be a lot if things. Since it bothers you at night you could have bed bugs. Another possibility is scabies. Or a rash or dry skin. First check your bed. Bed bugs hide in the mattress seams when they aren't active so you have to really look for them. If you do, they are hard to get rid of unless you use a professional exterminator.

If no bed bugs, go to the doctor. They can help figure it out.

And also... do you have pets? Did you? Did anyone in your house? Did you acquire any used things from someone who might have?