Reduction of antipyrine clearance in psoriasis.

Antipyrine clearance was determined in 41 psoriatics and age-sex matched controls, using sequential measurements of salivary concentration. Antipyrine clearance and elimination rate constant were less in psoriatics (P less than 0.05) and apparent volumes of distribution were similar. These differences were greater between female psoriatics and controls (P less than 0.025; P less than 0.05) and the differences between male psoriatics and controls were not significant. Correlation of simultaneous measurements of saliva and plasma antipyrine concentration in six psoriatics and age-sex matched controls showed no differences between the two groups. We conclude that antipyrine clearance is reduced in psoriasis but the underlying mechanism is unclear.