Ephebiphobia is a fear or dislike of teenagers. It is characterized by an irrational fear or aversion to adolescents, typically based on stereotypes and negative connotations associated with this age group. Symptoms of ephebiphobia may include avoidance of teenagers, anxiety when interacting with them,
From Wikipedia
Ephebiphobia is the fear of youth. Coined as the "fear or loathing of teenagers", the phenomenon is recognized today as the "inaccurate, exaggerated and sensational characterization of young people" in a range of settings around the world. Studies of the fear of youth occur in sociology and youth studies. It is distinguished from pedophobia by being more focused on adolescents than prepubescent children.