In this issue of the JCI, Aberg and colleagues report that psychological stress disrupts the skin's antimicrobial barrier and increases the severity of cutaneous infections (see the related article beginning on page 3339). This effect is mediated by endogenous glucocorticoids produced secondarily to stress-related activation of the hypothalamic-pituitary-adrenal axis. Thus, this study provides what I believe to be the first mechanistic link between psychological stress and increased susceptibility to microbial infection.