My leg feels llike it's on fire and my spine itches.

Yes. But probably not for the same reason you do.

Sounds like you pinched a nerve.

Multiple sclerosis is a condition that affects the central nervous system. Its symptoms affect the nerves and can cause dysesthesia, or abnormal sensations such as burning, numbness, or itching. ... MS itching can range from a minor bother to a stinging itch or a feeling of having pins and needles but there are other reasons like being diabetic

Sounds like nerve pain.

Nope. Usually my arm starts to go numb, then it travels up my shoulder and neck and makes my jaw numb...the pins and needles afterward are amazingly uncomfortable.

Dry skin.... And leg pain may be....🤔

Sounds like you need to see a doctor,