Joint Pain and Proteinuria

Abstract

A 66-year-old man with a history of bilateral carpal tunnel syndrome was evaluated for chronic joint pain and stiffness involving the shoulders, hips, and knees over the past 6 years. He had no fever, skin rash, headaches, vision changes, or urinary symptoms. He reported occasional bruising around his eyes. His only medication was acetaminophen as needed for pain. His vital signs were normal. No joint tenderness, warmth, or fluid collections were present, and skin examination was normal. The presence of raised soft tissue masses around the sternoclavicular joints (Figure, left panel) and scapulae (Figure, right panel) were noted. Laboratory evaluation revealed normal results for complete blood cell count, erythrocyte sedimentation rate (ESR), and levels of electrolytes, creatinine, and C-reactive protein. A spot urinalysis showed a protein level of 220 mg/dL (reference range, <26 mg/dL), and a 24-hour urine collection revealed 1.8 g of albumin (reference range, <229 mg/24 h). Magnetic resonance imaging (MRI) of the shoulders and hips showed synovial and capsular thickening.

When to Suspect a Diagnosis of Amyloidosis

“…Joint deposition of amyloid can cause joint pain and stiffness, and on physical examination the shoulder pad sign (Fig. 2) is a classical sign of amyloidosis [44]. Periorbital purpura (Fig.…”