Endogenous Ochronosis with a Fatal Outcome

Abstract

Endogenous ochronosis (EO) is an autosomal recessive inherited disorder where there is incomplete oxidation of tyrosine and phenylalanine due to a lack of the enzyme homogentisic acid oxidase. We report a singular observation of EO with a fatal outcome. We report the case of a 46-year-old man born to consanguineous parents with a medical history of recurrent renal colic and chronic nonspecific arthropathy. On clinical examination, slate blue pigmentation was seen on the cheeks, forehead, and nose, as well as blue-gray patches on all fingernails and bluish discoloration of the gums. Familial investigation revealed that his sister had similar pigmentation on the ears, hands, and fingernails. Histologic examination of a biopsy specimen from a pigmented lesion showed a dermal deposit of an acellular, eosinophilic material without cell reaction. Based on the clinical and histopathologic data, combined with the family medical history, our patient was considered to have EO with mucocutaneous, articular, and renal involvement. Unfortunately, the diagnosis was late because our patient died a few months later of terminal renal failure. Skin signs are the hallmarks of EO and must alert the clinician to look for involvement of vital organs.