Pruritus during standardized mental stress. Relationship to psychoneuroendocrine and metabolic parameters.

The influence of experimentally-induced emotional stress on pruritic response of human skin was studied in healthy subjects. Experimental activation of the psychoneuroendocrine system was produced by standardized stressors, i.e. a colour-word-conflict test (Stroop-test) and a subsequent mental arithmetic problem. Pruritus was elicited by intradermal injection of histamine. Results obtained were compared with reported feelings of stress, and stress-induced physiological and biochemical changes. Reported stress levels were evaluated by a visual analogue scale. The physiological and biochemical observations included pulse rate, blood pressure, endocrine and metabolic parameters. The experimental model produced adequate psychoneuroendocrine stress reactions. Cutaneous responses to histamine remained despite this unaltered. The cutaneous responses were unrelated to reported stress levels as well as to physiological and biochemical variables prior to stressor exposure. The individual cutaneous reactions to stressor exposure were related to the adrenaline response pattern. Degree of control, ability to predict, and time limitation of the experimental situation may be important factors influencing the experimental outcome.