beware of kissing-you might end up dead

Experts have found that even brushing teeth or waiting hours after eating may not prevent some partners of people with food and medicine allergies from triggering an allergic reaction through a kiss

Kissing" allergies are most commonly found in people who have food or medication allergies. Symptoms include swelling of the lips or throat, rash, hives, itching and wheezing. 

Allergists recommend that the non-allergic partner brush his or her teeth, rinse his or her mouth and avoid the offending food for 16 to 24 hours before smooching with a person who is highly allergic to that food. But even these steps may not help in some cases. 

for example,this 30-year-old male doctor with a peanut allergy who has had recurrent anaphylaxis, a life-threatening allergic reaction. 

This patient developed lip swelling and itching in his mouth when his girlfriend kissed him. She had eaten peanuts two hours earlier, brushed her teeth, rinsed her mouth and chewed gum prior to seeing him.