Periodic short stabbing type pain in back of head on left side ear level down to neck. Lasts maybe 5 seconds or less. No previous injury. Area feels sore now. Nothing seems to trigger it - just spontaneously happens.?

...Eruption..watch. Sounds like one is about to break out in Herpes III ( Shingles) eruption in that area. Watch for a few days to see if the rashes do break out ; else have MD take a look at the left side of the ear if Symptoms persist.