Pruritus in psoriasis: An update.

Abstract

Psoriasis is one of the most common chronic inflammatory skin diseases, found in about 1-3% of the general population. Pruritus affects about 60-90% of patients with psoriasis. The aim of this review was to summarize current knowledge about the pathogenesis and treatment of this symptom in psoriasis patients. Majority of psoriatic patients consider pruritus as the most bothersome symptom. The pathogenesis of pruritus is still unknown but the major concept of its origin is focused on neurogenic inflammation. Possible itch mediators include neuropeptides released from dermal nerve endings upon various stimuli, which were found to be abnormally expressed in itchy psoriatic plaques. Another important phenomenon supporting the idea of neurogenic inflammation as a key player in pruritus accompanying psoriasis is abnormal innervations of psoriatic skin. Possibly increased innervation density in psoriasis may decrease the threshold for pruritic stimuli. It is also suggested that pruritus in psoriasis might be related to abnormal functioning of the peripheral opioid system. Despite the high frequency of pruritus in psoriasis, to date there is no single antipruritic therapy dedicated specifically to treat itch in this disease. Neurogenic inflammation seems to be important for itchiness in psoriasis. Treatment of pruritus in patients with psoriasis should be directed towards the resolution of skin lesions, as disease remission usually is linked with pruritus relief.