Q: I’m a teenager with severe allergies to tree nuts and sesame seeds. If my boyfriend eats something that I’m allergic to, how much time should we wait before kissing?

Dr. Sharma: Dating can sometimes pose challenges for teens with food allergies, and kissing has been found to sometimes cause allergic reactions.

In two studies between 5 and 12 percent of patients surveyed reported such reactions. Most of those reactions involved kissing shortly after the food allergen was eaten.

Dr. Scott Sicherer and his colleagues at Mount Sinai in New York conducted a study investigating the presence of peanut allergen in saliva after participants (who weren’t allergic) ate peanut butter. They found that waiting several hours – an average of four hours – after eating peanut butter, then eating a peanut-free meal, reduced the allergen in saliva to undetectable levels.

It’s important to note that these findings are specific to peanut butter, and may not apply to other food allergens or peanut in another form.