儿童迁延性细菌性支气管炎的病因及鉴别诊断

The cause and differential diagnosis of protracted bacterial bronchitis in children

迁延性细菌性支气管炎（PBB）是引起儿童慢性湿性咳嗽的主要原因。PBB是一种慢性持续性的传导气道的细菌感染，越来越被认为是全球儿科重要疾病。PBB与上气道咳嗽综合征、气道软化有关。在PBB中有部分患儿合并变应性鼻炎、鼻窦炎。74％合并气道软化。也有研究认为腺病毒可能与PBB发病有关，腺病毒感染可能损害黏膜，引起气道的慢性炎症。胃食管反流或吸人也可能损害气道黏膜，也可能是PBB的病因。纤维支气管镜下可见气道壁水肿和分泌物增多。支气管肺泡灌洗液培养主要为嗜血流感杆菌、卡他莫拉菌和肺炎链球菌。PBB诊断并非特异，家长常诉有喘息，可能被诊断为支气管哮喘和胃食管反流，临床遇到反复顽固性支气管哮喘时要注意PBB的存在。PBB也可能为慢性化脓性肺疾病的前期、支气管扩张的前兆，反复发作的PBB可以发展为支气管扩张。原发纤毛功能障碍和囊性纤维化均为儿童慢性湿性咳嗽的原因，在早期未出现支气管扩张之前，需要行汗液氯离子测定和基因检测与PBB进行鉴别。因此，对于反复发作的PBB或对抗生素反应差时，一定注意慢性化脓性肺疾病、支气管扩张、原发性纤毛功能障碍和囊性纤维化的可能，还要注意免疫缺陷病的存在。

Protracted bacterial bronchitis （PBB） is a major cause of chronic wet cough in children. PBB is a chronic and persistent bacterial infection of the conductive airway, and is increasingly considered to be an important disease in the world. PBB may be associated with upper airway cough syndrome and tracheobronchomalacia. In some cases of PBB, allergic rhinitis and sinusitis were reported. A total of 74% were reported with tracheobronchomalacia. Adenovirus infection may be associated with PBB, and adenovirus infection may damage the mucosa and cause chronic inflammation in the airway. Gastroesophageal reflux or inhalation may also damage the airway mucosa, or may be the cause of PBB. In the flexible bronchoscopy, increased bronchial secretions and bronchial wall edema were found in the patient with the PBB. The culture of bronchoalveolar lavage is mainly Haemophilus influenzae and Moraxella catarrhalis and Streptococcus pneumoniae. PBB diagnosis is not specific, parents often complain of wheezing, and may be misdiaguosed as bronchial asthma, and gastroesophageal reflux, the PBB should be distinguished from the persistent asthma. PBB may be a precursor of the chronic suppurative pulmonary disease and bronchiectasis. Recurrent PBB may develop to the bronehiectasis. Primary cilia dysfunction and cystic fibrosis is the causes of chronic wet cough in children. Prior to the bronchiectasis in the early stages, it＇s need to test the sweat chloride and the gene mutation to identify the cystic fibrosis or primary cilia dysfunction from PBB. Therefore, when the PBB recurrent or poor response to antibiotic, the differential diagnosis of the PBB from the chronic suppurative pulmonary disease, brouchiectasis, primary cilia dysfunction and cystic fibrosis should be taken,it is also needed to identify the immune deficiency disease from PBB.