|MadSci Network: Immunology|
It is possible for a fragrance or some other cosmetic your roommate uses to produce exacerbations of allergic rhinitis (nasal itching, sneezing) and conjunctivitis (eye redness), presumably more on an irritant basis. It's also possible that an article of his clothing (e.g. wool) might also elicit allergic reactions.
Try the links in the MadSci Library for more information on Immunology.