View full lesson: ed.ted.com/lessons/does-stress-cause-pimples-claudia-aguirre Which came first: the stress or the pimples? The physical reactions to stress can cause major breakouts, which, in turn, can be even more stressful! Claudia Aguirre gives just one more reason to get that stress under control. Lesson by Claudia Aguirre, animation by Alan Foreman.