The primary hazard is transmission of an infectious disease:
(1) infectious mononucleosis (
Epstein-Barr Virus, EBV)
(2) hepatitis A, B or C
(3) primary or secondary syphilis
(4) Neisseria meningitides
(5) oral trichomoniasis (24.42.09)
(6) tuberculosis
(7) enteroviruses
(8) Lassa fever
Other hazards of kissing:
(1) anaphylaxis in a person with a severe food allergy (22.02.13), which may result in Kounis syndrome
(2) locking of dental braces (more apocryphal than real)
(3) bite injury of lip or tongue
(4) aspiration of a displaced dental appliance
(5) head or facial trauma following collision
Risk factors for complications of kissing:
(1) intoxication
(2) gingivitis and poor oral hygiene
(3) immunosuppression
(4) anger
(5) promiscuous behavior