Stressful life events and skin diseases: disentangling evidence from myth.

The possibility of a causal influence of emotional stress, especially of stressful life events, on the course of various skin diseases has long been postulated. Clinical wisdom and experience, as well as many anecdotal observations and uncontrolled case series, support this opinion. We reviewed the available evidence on the role of stressful life events in triggering or exacerbating skin diseases. The role of stressful events in vitiligo, lichen planus, acne, pemphigus and seborrhoeic dermatitis was either controversial or insufficiently explored. The role of stressful events in psoriasis, alopecia areata, atopic dermatitis and urticaria was apparently clearer. However, only a few studies met acceptable methodological standards for stress measurement. Also, few studies considered common potential confounding factors (e.g. age, duration of illness, familial factors), and no study controlled adequately for the influence of other crucial factors (e.g. discontinuation of treatment, seasonal effects). Adding that the large majority of studies were retrospective, it seems wise to conclude that only preliminary evidence has been published so far on the role of stressful life events in bringing on or worsening any dermatological disease. Further research is mandatory, either in the form of prospective studies or, more feasibly, of well-designed case-control studies with adequate statistical power. Future studies should also pay more attention to protective as well as vulnerability factors in stressful events. Further, it would be important to investigate other sources of psychological stress, such as chronic stress and everyday stress. Measuring stress appraisal, although difficult, would also be important.