I sympathize with your student! Over the years I have developed a serious
allergy to clay - or rather the mold spores that LOVE to breed in clay.
Every year I have a few students (with asthma) who usually have to take extra
precautions during clay projects as well.
There are a series of body "treatments" that can be used (invisi-glove for
hands)..and other various sprays (with silicone) that one can/should spray on
in a "clean" (read: mold free) environment (at least one hour) prior to
working with clay. The silicone acts as a protective barrier which can be
washed off at the end of the day- and is non-comudagenic (sp?....meaning,
doesn't block pores, still lets skin breathe)