Impact
When your fingers or other body parts touch stinging nettle's leaves or stems, the histamine and acetylcholine in the nettle hairs cause your body to release its own histamine as a defense measure. If, for example, you grasp stinging nettle with your hand, you can expect immediate feelings of intense itching and burning in your fingers and palm. The feelings often linger for most of the day, although they settle into a numbness or tingling after several hours.