Why is it that ground black pepper makes me sneeze?
And why don’t other kinds of peppers make me sneeze?
I don’t know your particular case, but black pepper causes a sneezing reaction because it is an irritant. I seem to recall that the molecules are jagged, but it could also be that the essential oils are merely irritating. Other ground peppers (white, red – the ones that are little berries) should cause reaction, because they are essentially the same plant.
Green and red bell peppers are probably not much of an irritant. The various hot pepper varieties certainly are, but aren’t served in powder form, so they can’t get up your nose to irritate it. (Even red pepper that you sprinkle on food is in the form of large flakes, not small bits of powder.)
Read “Sundials” in the new issue of Aboriginal Science Fiction.
www.sff.net/people/rothman
Strictly speaking, hot peppers are chilies and not related to (black) pepper. I recall that they got the name pepper for the same reason that Native (North) Americans got the name Indian, though this may be an UL. Cayenne chiles are usually powdered.
Au Contraire. There are any number of finely ground chile pepper powders on the market. I have about 6 or 7 that I use regularly. Snort a line of Red Savina™ powder and you’ll never go back to coke. Sneezing, however, will be the least of yer problems. 
Don’t try this at home kids.
JB
Lex Non Favet Delicatorum Votis