"A pimple is an impurity inside," Pagano explained. "There's something going on that needs to be released, but you're not letting it go." This could be due to "any kind of toxicity" — maybe you're drinking too much, or not eating right. It could also mean that you're hanging out with the wrong crowd, or spending too much time with people who don't make you happy.
Be warned: this nightmare might be a sign that you're at the end of your rope. "Pimples come to a head," Pagano said. "So no matter what your dream is a metaphor for, it means there a toxin in your life that cannot be ignored any longer."