Clinical Manifestation of Alkaptonuria and Ochronosis

Abstract

In the clinical picture of genuine human alkaptonuria, excretion of homogentisic acid in urine remains the only pathological sign for decades. Meanwhile in the body of the patients with alkaptonuria, the process takes place that is much more serious from pathological-anatomical as well clinical point of view – deposition of homogentisic acid and its derivatives in some tissues causes their discoloration. According to Burger (1954), vital staining of so-called bradytrophic tissues takes place. Basically it is a benign process that is asymptomatic for a long time. As time goes by, age and lower resistance of tissues prepare the conditions for pathological changes, namely, of degenerative character, with the subsequent manifestation of articular as well as extra articular signs. Tissues containing homogentisic acid and its oxidative polymer – pigment – have typical yellow-brown or even black colour. The first pathological-anatomical description of this disease was made by Virchow in 1865 (Virchow 1866).