Somatic and psychiatric comorbidity in patients with chronic pruritus.

It has been reported that 10-50% of patients with pruritus but no skin rash have an underlying systemic disease and up to 70% a psychiatric one. The aim of this retrospective study was to review the records of a large number of patients with chronic pruritus for concomitant diseases and treatment options. Medical records of 139 patients (52 males, 87 females) with chronic pruritus who visited the outpatient dermatological clinic during a 17-month period were reviewed. Itch was the presenting symptom in 6 of 47 patients with systemic disease and in 17 of 31 patients with psychiatric disease. Twenty-four patients had neuropathic itch and 37 patients had pruritus of unknown origin. The most severe and long-lasting itch was found in patients with multiple systemic diseases and in those with pruritus of unknown origin. Pruritus of the scalp and face was most common in psychogenic pruritus. Phototherapy was found to be a useful therapeutic option. In conclusion, systemic diseases are unlikely to cause chronic pruritus in patients consulting a dermatology department.