Sometimes get strange pains in my back, arms and legs that feel as though i am being stung. what could cause this?

Neuritic pain: The term for such pain is neuritic or neuropathic pain. The nerves are irritable and cause inappropriate sensations that are distressing. A common cause is medication effects or diabetes. Very regional neuritic pain occurs with shingles - a post herpes disorder. A thorough medical and neurological evaluation would be appropriate.