The plague of the 21st century, affecting 99% of the female population between ages 12-25. This disease is catagorized by the excessive use of the word "like", overreaction to trivial things such as boys, clothes, make up, explicit "love" stories, and terrible bands, artists, or groups in the music industry, such as the Jonas Brothers, Taylor Swift, Lil Wayne and more, and spontaneous meltdowns. There is no treatment for teengirlitis besides a good slap in the face or a kick in the ovaries. With time, the disease eventually devours itself and the sick returns to what is left of her rational mind, but the disease never truly goes away--it simply becomes dormant, waiting to strike at any given moment. Also associated with Fan Girl Syndrome (FGS)
My mom's so obsessed with how she looks, it's like she never recovered from teengirlitis.