ascorbic-acid and Spondylarthropathies

Alkaptonuria is a disease often forgotten because of its rarity. Its pathogenic mechanism is the deficiency of one of the enzymes of the tyrosine degradation pathway-homogentisate-1, 2-dioxygenase, which sequelae is accumulation and deposition of its metabolite homogentisic acid in connective tissues and urine. Alkaptonuria presents as a clinical triad-darkening urine upon prolonged exposure to air, pigmentation of connective tissues and debilitating arthropathy. We present a case report of a 67-year old patient with alkaptonuria who presented with the clinical triad, but was mistakenly diagnosed as having ankylosing spondylitis in the past. Currently there is no treatment for the disease hence the management strategy was focused on symptoms control with analgesics, physical therapy, dietary modification, vitamin C supplementation, and joint arthroplasty. Alkaptonuria's clinical features are extensively described in the literature and despite the fact that it is a rare disease, due to the similar radiographic changes with spondyloarthropathies, it should be included in the differential diagnosis in young patients presenting with severe joint involvement. Early recognition of the disease is necessary since its natural evolution is joint destruction leading to significant reduction in the quality of life. Alkaptonuria's articular features in the spine and peripheral tissues are well described using the classical imaging techniques. Musculoskeletal ultrasonography shows a characteristic set of findings in the soft tissues, including synovium, cartilage, tendons and entheses.

Topics: Aged; Alkaptonuria; Ascorbic Acid; Cartilage Diseases; Dioxygenases; Homogentisic Acid; Humans; Joint Diseases; Ochronosis; Osteoarthritis; Quality of Life; Spondylarthropathies; Tyrosine

Alkaptonuria is a rare autosomal recessive metabolic disease that leads to the deposition of homogentisic acid. Ochronotic arthropathy is the articular manifestation of alkaptonuria with the most common clinical feature being severe spondyloarthropathy. We present the case of a 58-year-old woman with back pain. Radiographs and magnetic resonance imaging (MRI) revealed characteristic features of ochronotic spondyloarthropathy. The literature regarding management of alkaptonuria is reviewed.

Topics: Alkaptonuria; Antioxidants; Ascorbic Acid; Female; Homogentisate 1,2-Dioxygenase; Homogentisic Acid; Humans; Low Back Pain; Middle Aged; Ochronosis; Spondylarthropathies