Clinical Images: Alkaptonuria: a conundrum

A 74-year-old hypertensive male presented with longstanding generalised aches, flexor contractures of the palms, and progressive tingling and numbness in his extremities. Examination reported classic signs of ochronosis, including blackish pigmentation of the pinna and sclera, along with synovitis, spinal deformities, and calcification of intervertebral discs, menisci, and prostate. Cardiovascular assessment revealed mitral valve involvement, while neurological studies confirmed axonal neuropathy. The patient's urine turned black on sunlight exposure, and an elevated urinary homogentisic acid test confirmed alkaptonuria. This case highlights multi-systemic involvement of alkaptonuria (AKU), emphasising the importance of identifying its clinical triad: dark urine, ochronosis, and arthropathy, for timely management.