The possibility that stress aggravates acne is less easy to prove. If the action of stress is on the sebaceous gland, the resultant slow response will mean a delay between the stimulus and its effect.

  Kenyon found no evidence for acne being initiated de novo by psychological factors. However, he did find in the predisposed individual that exacerbation of acne can occur as a result of emotional stress. Other studies have demonstrated a  flare-up of acne in  medical students (eight males and one female) associated with the stress of a compulsory academic examination.45 If acne is made worse by stress,  an effect on the modulation of inflammation is  the  most likely  profitable  route  of investigation.