According to entomologist Dr. Douglas Emlen, cockroaches that infest "large piles of coffee beans" are often just ground up instead of removed, since it would be too difficult to eliminate them completely. In the US, the Food and Drug Administration allows a certain amount of "insect filth" to be included in coffee, and other foods, as long as it doesn't exceed a pre-established percentage.

Thus, since it's actually pretty common for researchers to develop acute allergies to the specimens they study, entomologists who become allergic to cockroaches do indeed also become allergic to things like pre-ground coffee and chocolate.