Possible Clues:

• Violent explosion under the bridge?
• Something you close your eyes for
• Precursor to “bless you”
• Sign of allergy comes as a blow
• Sternutation— see Zen (anag)
• Scoff (at)
• It goes 'Ah-h-h-choo!'
• Pooh-pooh, with "at"
• Response to nasal irritation
• Partners and opponent, three times holding unknown hand, might catch this?