[Determination of urinary xanthurenic acid after oral loading of L-tryptophan in 88 cases of photodermatosis].

Abstract

Disturbances in the kynurenine pathway are present in pellagra and pellagroid syndromes. In 88 photodermatoses, the authors found increased urinary excretion of xanthurenic acid after oral load of tryptophan in a number of light-induced eruptions, i.e. benign summer photodermatosis (40%), polymorphous light eruptions (37%), and persistent light reactions (36%) as well as in patients with acute alcoholic intoxication. These biochemical abnormalities in the kynurenine pathway allow for a pathogenetic approach in some photodermatoses.