PHOTOSENSITIVITY AND DISTURBANCES OF TRYPTOPHAN-METABOLISM (KYNURENIN PATHWAY)

Abstract

A bullous photodermatosis recurring for 2 yr in an elderly woman was studied. The eruption was diagnosed by the tryptophan loading test as a pellagra-like syndrome without any other cause of sun sensitivity. The static and dynamic metabolic investigation was centered on tryptophan and vitaminic coenzymes which mediate catabolic reactions. The defects are located on the kinurenine pathway. The possible relationship between the dermatosis and the observed biological disturbances are analyzed.