继发性肺炎病原常见肺炎链球菌、流感杆菌、金黄色葡萄球菌或腺病毒等，多发生于出疹期。
B-dis I-dis I-dis I-dis I-dis O O O O B-mic I-mic I-mic I-mic I-mic O B-mic I-mic I-mic I-mic O B-mic I-mic I-mic I-mic I-mic I-mic I-mic O B-mic I-mic I-mic O O O O O O O O O O