What are the signs and symptoms of pseudogout (calcium pyrophosphate deposition disease)?

Signs and Symptoms of Pseudogout (CPPD)

Pseudogout typically presents as acute monoarticular or oligoarticular arthritis affecting large joints—most commonly the knee—with sudden onset of severe pain, swelling, and periarticular erythema, often accompanied by systemic symptoms including fever, chills, and weakness. 1, 2

Clinical Presentation Patterns

Acute CPPD Crystal Arthritis (Classic Pseudogout)

• Sudden onset of severe joint pain with rapid development over hours to days 2
• Swelling and periarticular erythema at the affected joint 2
• Systemic symptoms including fever, chills, and generalized weakness 2
• Monoarticular or oligoarticular involvement, distinguishing it from polyarticular presentations 3, 2

Joint Distribution

• Large peripheral joints are characteristically affected, particularly:
  • Knees (most common site) 1, 2
  • Wrists 1, 2
  • Shoulders 4
  • Ankles 2
  • Hips (less common but can mimic septic arthritis) 4
• Acromioclavicular joint involvement occurs rarely 5
• Atypical joint distributions that mimic osteoarthritis, including radiocarpal, metacarpophalangeal, and patellofemoral joints 1

Axial Involvement (Rare but Important)

• Cervical and thoracic spine involvement can present with neck and back pain 6, 2
• May mimic spinal infection (discitis, epidural abscess) with clinical and radiographic features that are difficult to distinguish from infection 6, 2
• Skip lesions throughout the spine can occur 6
• Crowned dens syndrome presents as acute neck pain with calcification around the odontoid process 3
• Mass effect symptoms including foramen magnum syndrome, spinal stenosis, radiculopathy, myelopathy, or cauda equina syndrome 2

Clinical Mimicry and Diagnostic Pitfalls

Septic Arthritis Mimicry

• Pseudogout can present identically to septic arthritis, making joint aspiration essential when infection is in the differential 7, 4
• Both conditions can coexist, necessitating synovial fluid analysis for both crystal identification and Gram stain/culture 3

Chronic Presentations

• Chronic CPPD crystal inflammatory arthritis may present with persistent joint symptoms rather than acute attacks 2
• Osteoarthritis with CPPD presents as progressive joint disease with superimposed inflammatory episodes 2
• Asymptomatic CPPD exists where chondrocalcinosis is present radiographically without clinical symptoms 2

Associated Clinical Features

Patient Demographics

• Older adults are predominantly affected, with prevalence increasing dramatically after age 70 7
• Multiple medical comorbidities are commonly present 1

Associated Metabolic Conditions

• Primary hyperparathyroidism 8
• Hemochromatosis 8
• Hypomagnesemia (including medication-induced from furosemide) 8

Peripheral Joint Manifestations

• Wrist and ankle erythema, pain, and swelling may develop, sometimes after spinal involvement 6

Key Diagnostic Indicators

Clinical Red Flags Suggesting Pseudogout

• Acute monoarticular arthritis in an elderly patient with large joint involvement 1, 7
• Recurrent acute attacks affecting different large joints 3
• Inflammatory arthritis with atypical osteoarthritis distribution 1
• Acute neck or back pain in elderly patients that should prompt consideration of axial CPPD 2

Distinguishing from Gout

• Joint distribution differs: pseudogout characteristically affects larger joints (especially knees), while gout typically affects the first metatarsophalangeal joint 1
• Clinical presentation alone cannot reliably distinguish between gout and pseudogout—synovial fluid analysis is required for definitive differentiation 1