痛风病人痛风性关节炎是由关节处尿酸盐结晶沉积引起。如图所见的第一MP关节（大拇趾），它是最常受影响的关节。急性发作是以剧痛、肿胀与关节红斑为特征。

痛风性关节炎：大拇趾肉眼 X线 软组织内痛风石(低倍镜) 关节液查见尿酸盐结晶

This is gout. Gouty arthritis results from deposition of sodium urate crystals in joints. The joint most often affected is the first MP joint (big toe) as seen here. Acute attacks are characterized by severe pain, swelling, and erythema of the joint.