Polymyalgia rheumatica presenting as sternoclavicular arthritis: a case report

BACKGROUND: Polymyalgia rheumatica and giant cell arteritis are systemic inflammatory conditions of the elderly. Polymyalgia rheumatica classically presents as a bilateral proximal muscle pain and stiffness syndrome. Biceps tenosynovitis is the commonest pathology in polymyalgia rheumatica. However according to literature, erosive sternoclavicular arthritis is a rare association of polymyalgia rheumatica. Giant cell arteritis is an inflammatory granulomatous arteritis predominantly involving large cerebral arteries. Thus, its classic clinical presentation includes severe headache with scalp tenderness, jaw claudication, and sudden painless loss of vision. Urological manifestations (prostatic vasculitis and epididymo-orchitis) were seldom reported in giant cell arteritis. CASE PRESENTATION: A 53-year-old Sinhalese man presented with progressive right-sided shoulder joint pain and neck pain associated with constitutional symptoms and episodic generalized headache. Examination revealed restricted movements of the right shoulder joint with nontender pulsatile bilateral temporal arteries. Blood testing showed elevated erythrocyte sedimentation rate and C-reactive protein. Color Doppler ultrasound of the superficial temporal artery revealed “halo sign.” The temporal artery showed infiltration of mononuclear cells in the arterial media and adventitia. Computed tomography revealed right sternoclavicular arthritis with incidental finding of ureteric stricture. The patient was treated with high-dose oral prednisolone, and good clinical and biochemical response was observed during follow-up. CONCLUSION: Polymyalgia rheumatica–giant cell arteritis may rarely present as erosive sternoclavicular arthritis as the initial manifestation, mimicking many rheumatological conditions. Urological involvement such as ureteric strictures may be rare associations of primary systemic vasculitis. A high degree of suspicion combined with targeted investigations would allow early identification the polymyalgia rheumatica–giant cell arteritis syndrome in the presence of atypical manifestations, leading to improved patient outcomes.