It is widely accepted that psychosocial stress can result from the daily strains of living with a diagnosis of psoriasis. There is now an evolving body of work to suggest that psychosocial stress may also play a role in the exacerbation of psoriasis. We discuss the historical evidence supporting a temporal relationship between psychosocial stress and the exacerbation of psoriasis. The underlying pathophysiological mechanisms by which this occurs are largely unknown, but current evidence points towards a role for nerve-related factors, namely their interaction with mast cells and the potentiation of neurogenic inflammation in this regard. It is also likely that the physiological stress response in patients with psoriasis differs from that in healthy individuals, as evidenced by alterations in the hypothalamic-pituitary-adrenal axis and sympathetic-adrenal-medullary system function. Psychological stress results in a redistribution of leucocytes with increased trafficking of inflammatory cells into the skin, which may exacerbate psoriasis. Langerhans cells play a role in the stress response of normal skin; their function in the stress response of patients with psoriasis is open to speculation. We discuss the influence of stress reactivity in patients with psoriasis and the impact of stress reduction strategies in the management of psoriasis. Finally, we suggest potentially fruitful areas for future research. What's already known about this topic? There is a temporal relationship between psychosocial stress and the exacerbation of psoriasis. The mechanism by which psychosocial stress causes such an effect is largely unknown. Addressing both the psychosocial and physical aspects of psoriasis improves patient outcome. What does this study add? A summary of the historical studies that support a temporal relationship between psychosocial stress and the exacerbation of psoriasis. A review of the pathophysiological mechanisms by which psychosocial stress may exacerbate psoriasis. A rationale for considering the psychosocial aspects of psoriasis when constructing a patient management plan. © 2013 British Association of Dermatologists.