There's also kerchoo
(Joan Heilbruner's Robert the Rose Horse, 1962); ka-choo (Rosetta Stone's Because a Little Bug Went Ka-Choo, 1975); ka-chow (James Flora's The Day the Cow Sneezed, 1957); and atishoooooooooo (Ruth Brown's The Big Sneeze, 1985).
Despite the usual reading of the pope's open mouth as a sign of existential nausea - universal scream on the order of Edvard Munch's famous image - I always read it, in the Vassar version with which I was familiar at any rate, Study for Portrait, IV, 1953, as a sneeze, which reduced the papal being, or rather, Velazquez's famous image of Innocent X, to a modern photo-op, the pope's partially covered mouth agape in a vigorous and nonexistential kerchoo
. In Bacon's portrait, temporal immediacy and mere physical reflex wittily undermine the pictorial effects of hierarchy and permanence.