The consumption of certain foods causes watery rhinorrhea (gustatory rhinitis) in many individuals. To examine the underlying mechanisms responsible for this common phenomenon, 12 subjects ingested control foods and positive foods (foods that cause rhinorrhea). Nasal lavages performed 10 minutes after each food challenge were analyzed for albumin and total protein. Positive food challenge, but not control food challenge, induced rhinorrhea in all subjects. Positive food challenge increased albumin (7.8 +/- 1.9 to 24.5 +/- 7.6 mg/L; p less than 0.025) and total protein (79 +/- 9 to 258 +/- 41 mg/L; p less than 0.001) without altering the ratio of albumin to total protein (albumin percent). Nasal pretreatment with atropine clinically blocked the positive food-induced rhinorrhea and significantly inhibited secretion of both albumin and total protein, again without affecting the albumin percent. Thus, gustatory rhinitis is produced by spicy foods that stimulate atropine-inhibitable muscarinic receptors (probably on submucosal glands), and the syndrome can be treated prophylactically by use of topical atropine.