I have a pin prick sensation and pain on my left fore head near that left artery... what may be the reason?

Head pain: Get an evaluation. You could have temporal arteritis, an inflammation which is diagnosed by a blood test (sed rate) and biopsy of the temporal artery on the side of you forehead.

Consider:: Pain in the forehead near the temporal artery can be important, particularly if you are a female over 50 years of age and smoke. A condition called Temporal Arteritis(or Giant Cell Arteritis) is an inflammation of the lining of arteries. The cause is unknown.> In this condition there may be swelling and tenderness on pressing over the Temporal Artery. Read about it here: http://bit.ly/ZdSR3m