I have had 2 episodes of very sudden onset of left sided nose irritation; initial onset came with intense sneezing that couldn t be interrupted - 10-12 times. Sneezing continued first day but less intense and not as long. Followed by nonstop clear nasal draining on left side. This was accompanied with intense irritation high in nasal passage -ethmnoid area. Irritation was itching, painful, constant. Had to blow nose about every 30-60 seconds to avoid nose just dripping. This went on for 2 days, very acutely the first time. Drove me crazy. I took Benadryl, Allegra, used Flonase and lots of cold pack to nose. At times the upper part of nose on left was throbbing with pain, but continued with only clear drainage. It took 5 days to go away. About 2 days after that I developed a cold sore above lip, a little left of center. (I do have a history of cold sores; always have been only on lips). The second episode woke me in middle of night; sudden onset intense sneezing and immediate aggressive clear draining from left nasal passage. Tingling, irritation, itching, pain at same place left upper interior nose. Again I iced, took Benadryl, then after about 4 hours found old Rx prednisone 5 mg. I took one tab 3 times per day for 2 days, then two times per day, then 1/2 tab per day for 2 days. It has cleared. I am very afraid of it happening again without knowing what it is. The prednisone took care of it - but I don t want to repeat that without knowing what it is. It interferes with work, focus; non stop running nose. I can t have a conversation without holding a tissue to my nose. Both time exclusively on left side. Any thoughts?