text: 2.皮下结节少见，常伴有严重心脏炎，呈坚硬无痛结节，与皮肤不粘连，直径0.1～1cm，出现于肘、腕及踝等关节伸面，或枕部、前额头皮以及胸、腰椎脊突链球菌感染证据咽拭培养可发现A组β溶血性链球菌；近年来开展的咽分泌物A组链球菌抗原的快速鉴定，敏感性与特异性均很高，阳性率达90%左右；测定血清抗链球菌抗体，链球菌感染1周后血清ASO滴度开始上升，2个月后逐渐下降，80%患儿ASO升高；同时测定抗脱氧核糖核酸酶B（Anti-DNaseB）、抗链球菌激酶（ASK）及抗透明质酸酶（AH）则阳性率可提高到95%。
entities.entity: 皮下结节
entities.label: sym
entities.entity: 心脏炎
entities.label: dis
entities.entity: 结节
entities.label: bod
entities.entity: 皮肤
entities.label: bod
entities.entity: 肘
entities.label: bod
entities.entity: 腕
entities.label: bod
entities.entity: 踝
entities.label: bod
entities.entity: 枕部
entities.label: bod
entities.entity: 胸
entities.label: bod
entities.entity: 腰椎
entities.label: bod
entities.entity: 伴有严重心脏炎，呈坚硬无痛结节，与皮肤不粘连，直径0.1～1cm，出现于肘、腕及踝等关节伸面，或枕部、前额头皮以及胸、腰椎脊突
entities.label: sym
entities.entity: 链球菌
entities.label: mic
entities.entity: A组β溶血性链球菌
entities.label: mic
entities.entity: 咽
entities.label: bod
entities.entity: 链球菌
entities.label: mic
entities.entity: 血清
entities.label: bod
entities.entity: 链球菌
entities.label: mic
entities.entity: 链球菌
entities.label: mic
entities.entity: 血清
entities.label: bod
entities.entity: 抗脱氧核糖核酸酶B
entities.label: bod
entities.entity: Anti-DNaseB
entities.label: bod
entities.entity: 抗链球菌激酶
entities.label: bod
entities.entity: ASK
entities.label: bod
entities.entity: 抗透明质酸酶
entities.label: bod
entities.entity: AH
entities.label: bod