This happens about half to three quarters of an hour after I leave the pool and lasts about an hour with many tissues used. I managed to string together a sequence of eight sneezes non stop this morning.
To reassure those I come in contact with during a post swim sneezathon, I've always said I have an allergy to chlorine but a bit of research - ok, a quick google search - reveals that may not be the case.
Apparently the molecule is too small to stimulate the parts of your immune system that cause allergies. Similar to perfume, it is a chemical irritant and some people are more sensitive than others and this results in sneezes with every exposure.
Nose clips appear to be the recommended remedy but I'm not a gadget lover. However, if it doesn't settle down, I may have to at least give a nose clip a try.