Does psychosocial stress play a role in the exacerbation of psoriasis?

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.