There's no definitive 'common side effects; severe side effects; drug interactions' document online for Medical Marijuana, so..
I have mild pollen/plant allergies, nothing extreme though. Every time I medicate with marijuana by smoking, to a 'well medicated' degree, I find that my nose gets stuffy, but dry, shortly after, and then it goes away after 30-60 minutes, sometimes longer. I don't experience these effects when ingesting edibles, or using a vaporizer. Neither of those methods introduces plant material into your body, so I figure it's just that I'm slightly allergic to the plant material, but not the THC. It is not likely related to pollen, as typical medical grade marijuana is harvested from female ONLY plants which contain no pollen.
That would make something like this following article a bit irrelevant unless you work with maybe marijuana cultivation for hemp fiber harvesting I suppose? NYTimes article
I feel like it's an odd topic to start, but it's not really. You can be allergic to pretty much ANYTHING, all the meds we take, foods, plants, perfumes, so why not. I suppose I have just never thought 'can you be allergic to marijuana?'.
That's one area where millions of americans could benefit; if we had comprehensive, unbiased information on this medicine. But, we don't.. (come on FDA! =P)
Do you have the same problem? Any thoughts on the matter?