The prevalence and clinical characteristics of pruritus among patients with extensive psoriasis.

BACKGROUND: Many patients with psoriasis are known to suffer from itch. However, the data available regarding itch and its characteristics in psoriasis are sparse.

OBJECTIVES: To examine the prevalence of pruritus and various related clinical characteristics in 101 patients with extensive psoriasis.

METHODS: A structured questionnaire was used.

RESULTS: Generalized pruritus was a feature of psoriasis in 84% of the patients. In 77% of these it appeared on a daily basis. It involved all areas of the body, had prolonged duration and appeared mainly in the evening and at night. The pruritus significantly affected quality of life. Important daily factors that were found to exacerbate the itch were ambient heat (81%), skin dryness (80%), sweating (65%) and stress (55%). Important factors that were found to ameliorate itch were sleep (57%) and cold showers (55%). The pruritus was found to be unresponsive to most available antipruritics, including phototherapy. Itch intensity as reflected by a visual analogue scale did not correlate with Psoriasis Area and Severity Index scores; however, a highly significant correlation was obtained between the affective descriptors and itch intensity in the worst itch states (r = 0.6, P < 0.001).

CONCLUSIONS: Pruritus is a common feature of psoriasis and affects quality of life.