Hello. The information that states the effects of the medication causing swollen face, lips an dtongue relate to a person having an allergic reaction or anaphylaxis to the medication. This is actually possible with any medication on the market. There is always a rare possibility that someone can be allergic to a medication. They are not considered normal "side effects". If you were allergic to the alli, you would have a general reaction, it would not be limited to one nostril. If a drug is going to cause some sort of reation, it would be either local to the site where the drug works (in alli's case, the GI tract) or very generalized (like hives all over the body or swelling of the face, lips or tongue - common to an allergy).
As a pharmacist, I would not suspect swelling on one nostril to be related to a medication. I am sure your doctor will be able to properly asses this problem.
Hope you are feeling better soon.
Maria Marzella Sulli, Pharm.D.