Crystal arthritis

Crystal arthritis Main page
Patient Information Gout (patient information) Pseudogout (patient information)
Overview
Causes
Classification Gout Pseudogout
Differentiating Gout from Pseudogout

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] ; Associate Editor(s)-in-Chief: Aditya Ganti M.B.B.S. [2]

Overview

Crystal induced arthritis is a relatively common condition that involves deposition of crystals in joints and soft tissues. A variety of crystals can deposit in and around joints and soft tissues, resulting in articular and periarticular inflammation. Monosodium urate (MSU) and calcium pyrophosphate dihydrate (CPPD) are the most commonly involved crystals in the pathogenesis of crystal induced arthropathies. Other rare types of crystal arthropathy include hydroxyapatite crystal deposition arthropathy. Gout and pseudo-gout manifest with similar symptoms, and cannot be distinguished clinically. Synovial fluid analysis the involved joint is essential to diagnose and differentiation of crystal induced arthropathies.

Causes

• Gout
• Pseudogout (Calcium pyrophosphate dihydrate)
• Calcium apatite deposition disease

Classification

Arthritis

Inflammatory

Non-Inflammatory

Osteoarthritis

Rheumatoid factor

Infectious

Crystalloid

Rheumatoid positive

Rheumatoid negative

RA Lupus Scleroderma

AKS Psoriatic arthritis Reactive arthritis

Gout

Pseudogout

Calcium hydroxapatite crystals

Differentiating Gout from Pseudogout

Gout can be differentiated from pseudogout based on the following characteristics:

	Gout	Pseudogout
Definition	Supersaturation of extracellular fluids and plasma with uric acid leading to monosodium urate (MSU) crystal deposition in the joint spaces is called gout.	Acute and chronic inflammatory joint disease leading to deposition of calcium pyrophosphate dihydrate (CPPD) deposition in the joints leads to pseudogout.
Pathogenesis	Increased production or decreased excretion of uric acid leads to hyperuricemia.	Shedding from articular cartilage into joint space where they are phagocytosed by neutrophils and incite an inflammatory response, leading to crystal formation.
Clinical Features	Acute arthritis: Pain Swelling of the joint Warmth Tenderness Chronic arthritis: Chronic nonsymmetric synovitis Periarticular tophi formation Nephrolithiasis Renal colic	Acute CPPD arthritis: Pain Swelling, frequently involving the knee Redness Chronic arthropathy: Progressive degeneration in multiple joints Symmetric proliferative synovitis
Diagnosis	Joint aspiration: Synovial fluid analysis shows both intracellular and extracellular needle-shaped negatively birefringent MSU crystals by polarizing microscopy Serum uric acid levels Urine uric acid Serum creatnine levels	Synovial fluid analysis: Demonstration of CPPD crystals appearing as rhomboids with weak positive birefringece by polarizing microscopy
Treatment	Analgesia NSAIDs Intraarticular glucocorticoids Systemic glucocorticoids Allopurinol, Febuxostat Probenecid, Sulfinpyrazone	NSAIDs Intraarticular injection of glucocorticoids Colchicine