Alkaptonuric ochronosis: Report of two affected brothers

Endogenous ochronosis with a fatal outcome

BACKGROUND

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.

OBJECTIVE

We report a singular observation of EO with a fatal outcome.

CASE REPORT

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.

CONCLUSION

Skin signs are the hallmarks of EO and must alert the clinician to look for involvement of vital organs.

Endogenous ochronosis: case report and a systematic review of the literature

BACKGROUND

Endogenous ochronosis (EO) is a rare autosomal recessive disorder due to accumulation of oxidized and polymerized forms of homogentisic acid (HGA) in connective tissues, giving them a deep dark blue pigmentation.

AIM

Through a new Tunisian case of EO and a review of the literature, we aimed to define the epidemioclinical features of EO, its diagnostic criteria, and evolution.

METHODS

Three hundred and forty patients were enrolled through 54 articles and four abstracts.

CASE REPORT

A 35-year-old woman, born in consanguineous parents, presented with blue-grey patches of fingernails, first interdigital spaces, and ears with brown conjunctival pigmentation. Urine specimen turned dark on standing overnight. The diagnosis of EO was confirmed by urinary high levels of HGA. Investigations revealed radiologic signs of ochronotic arthropathy.

REVIEW OF THE LITERATURE

EO is ubiquitary. Its prevalence was estimated at almost 6.5 cases/year. The mean age at diagnosis was 55.9 years (M/F: 1.85). Onset symptoms mainly consisted in cutaneous signs. Ochronotic arthropathy was the most frequently reported manifestation. Treatment was mainly symptomatic.

DISCUSSION

EO is often revealed in adulthood mainly after the fourth decade. Urinary darkening is the first sign of the disease but is rarely reported as an onset sign. Skin signs are the alerting features. Ochronotic arthropathy is insidious but may be debilitating. No specific medical treatment of EO is available.

CONCLUSION

Cutaneous manifestations are the hallmarks of OE. As vital organ involvement has been reported, close monitoring and continuous surveillance is warranted.

Arthroscopic treatment of shoulder ochronotic arthropathy: a case report and review of literature

Alcaptonuria is an inherited hereditary metabolic disorder, which is associated with various systemic abnormalities and related to the accumulation of homogentisic acid and a derived melanine-like pigment in the connective tissues; the latter is termed ochronosis. We present the arthroscopic findings in the shoulder of a 58-year-old female with ochronotic arthropathy and discuss the role of arthroscopy in the diagnosis and management of this rare metabolic disorder.

Alkaptonuric ochronosis presenting as palmoplantar pigmentation

We describe a 37-year-old woman who presented with palmoplantar pigmentation, thickening and pitting of 4 years duration. Bluish pigmented patches were seen over the sclera of her eyes. Her lumbar spine showed typical calcification of the intervertebral discs. Addition of Benedict's reagent to a urine sample of the patient gave rise to greenish brown precipitate and brownish black supernatant. Alkalinization of urine turned it black. A biopsy of the palmar lesion demonstrated irregular breaking up, swelling and homogenization of collagen bundles in the reticular dermis. Yellow-brown (ochre coloured) pigment was seen lying within the collagen bundles and also freely in the deeper dermis confirming our clinical diagnosis of alkaptonuric ochronosis. To the best of our knowledge this is probably the second report of alkaptonuria presenting with palmoplantar pigmentation.