While many rashes that befall bakers and others who handle
baking products are attributed to parasites (mites, etc., that
thrive in flour, sugar, yeast -- YUK!) there is research linking
baking yeast to fungal infections in humans.

"...microbiologists in Italy and the United States (US) have
shown that commercial strains of bakers' yeast,
saccharomyes cerevisiae, can cause thrush, an infection of
the mouth or throat in infants or of the vagina in
women...According to the monthly Journal of Clinical
Microbiology, a Santa Clara Valley Medical Centre [USA]
publication, [Karl] Clemons and his team decided to
investigate bakers' yeast after seeing isolated reports of it
causing thrush. In the journal, it was reported that Claudio
Farina of the United Hospital in Bergamo, Italy, sent the
Santa Clara team samples from 16 women with thrush
whose symptoms were not caused by candida albicans. All
16 samples contained a strain that is sold in Italy for
cooking."

Full text of the article is located on the Internet at
http://www.africanews.org/science/stories/19970908_feat1.html

~~Margery Wilson, IBCLC
Massachusetts Institute of Technology
Cambridge, Massachusetts, USA