allergic rhinitis
"I occasionally get severe sneezing attacks, cause unknown.  They start as a feeling like something tickling my nose followed by a deep intake of breath and a powerful (mostly dry) sneeze.  This then repeats about every 20 seconds for several minutes, when it stops, leaving me exhausted and with teary eyes and a runny nose.  I found that swallowing a short-acting chlorpheniramine maleate tablet at the first sign, or in between sneezes, is effective at immediately stopping the attack, with no noticeable side effects.  I have other chronic health conditions for which I take  prescription medications; long term use of antihistamines for me is not recommended."