No. That's not how that works. No one is allergic to coffee because they are allergic to cockroaches/chitin. People are allergic to coffee because they are allergic to coffee. Maybe you meant to say that there are people who can't drink coffee that is brewed from pre-ground beans that also have chitin/cockroaches in it?
Otherwise it's exactly how it works. You're either stupid or misinformed. Go fix that.