I've often wondered about the latex allergy rearing its ugly head with the CPAP masks. A few years ago a local teacher developed an intolerance, and was aware that rubber gloves for dishwashing and other items were causing her to have rashs, etc.

One day she had a banana (which has a connection with latex) and her husband awakened in the middle of the night to discover her choking and turning purple. By the time he got her to the hospital she was essentially a vegetable and remained so. It is a sad and really scary example of what a severe allergic reaction can do.