Case Report Article

Misdiagnosis of alkaptonuria in an elderly patient

Georgia C. Tseliou¹, Mayra P. Giannelou¹, Evangelos A. Boulios¹, Anastasia K. Klangou¹, George N. Katsoulis², George D. Bailas¹, Athanasios I. Georgountzos¹

1. Department of Rheumatology, "G.Gennimatas" General Hospital, Athens, Greece
2. Department of Endocrinology, "Agios Savvas" Anticancer Hospital, Athens, Greece

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Keywords: Alkaptonuria, Ochronosis, Homogentisic acid (HGA), Low back pain, Degenarative arthropathy

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Abstract

Alkaptonuria is a rare hereditary metabolic disorder, resulting from deficiency of enzyme homogentisate 1,2-dioxygenase (HGD). Its features include spine and peripheral joint arthritis, as well as bluish discoloration of cartilage tissues. We report a case of an 81 year old male with a 5 year history of low back pain and progressively increasing stiffness of the spine, incorrectly diagnosed as ankylosing spondylitis and treated with non steroid anti-inflammatory drugs (NSAIDs) and sulfasalazine. Diagnosis of alkaptonuria was based on the characteristic ochronotic pigmentation of ears and eyes cartilage and typical radiographic findings of the spine-narrowed intervertebral spaces and intervertebral disc calcification, combined with the presence of homogentisic acid in the patient’s urine. Complete history,physical and radiological examinations revealed severe degenerative arthropathy of knee, hip and shoulder joints, which had led to bilateral total hip and knee arthroplasty in the last 7 years. Due to the patient’s cardiovascular comorbidity and advanced age, surgical treatment of ochronotic spine arthropathy was not considered. Management of the patient was based on analgesic treatment and vitamin C. Although alkaptonuria is a rare disease it should be considered in patients, even the elderly ones, who present with low back pain and severe degenerative arthropathy.

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