Physical Findings

Stop & Think

Lab and X-Ray

Differential Diagnosis

The Disease

Treatment

Conclusions

Quiz & Evaluation

• A number of substances may precipitate as crystals in joint fluid, but the two most common are:
• Urates in the case of gouty arthritis
• And calcium pyrophosphate in the case of pseudogout
• In the case of gout, the uric acid crystals
• Are phagocytized by PMNs, which cause
• The PMNs to lyse, releasing lysosomal enzymes,
• Which cause tissue injury and inflammation.
• Uric acid crystals phagocytized by monocytes,
• Cause the release of IL-1, TNF, IL-6, etc.
• These monocyte mediators of inflammation cause
• Release of proteases, which
• Cause additional tissue injury and inflammation.
• An acute, gouty joint is RED and PAINFUL.
• Occasionally we see uric acid deposits in soft tissue.
• A tophus; helix of ear, around a joint, extensor surfaces.