Schroeckenstein D C, Busse W W
Department of Medicine, University of Wisconsin, Madison.
Semin Respir Infect. 1988 Mar;3(1):40-8.
Lower respiratory tract infections in children, including group, bronchiolitis, and bronchitis are frequently associated with recurrent episodes of wheezing. Different respiratory viruses assume greater importance at different ages of children. Respiratory syncytial virus is the most prevalent viral respiratory infection in preschool children, while rhinovirus is of increasing importance in older children. Asymptomatic virus shedding and mild respiratory infections do not provoke asthma symptoms nor do bacteria, except in association with sinusitis. Furthermore, epidemiologic studies strongly suggest that viral lower respiratory tract illness in early childhood is associated with pulmonary abnormalities, including bronchial hyperreactivity and peripheral airway obstruction that may persist for many years, and is possibly a cause of chronic airway obstruction in adulthood. Several different mechanisms have been identified by which respiratory viruses provoke asthma. No one single mechanism, however, adequately explains virus-induced asthma. Nonetheless, a common thread to these various proposed mechanisms is the ability of respiratory viruses to cause airway inflammation, either directly, through cytopathic effects, or indirectly, by increasing the inflammatory processes of respiratory cells. The consequence of these effects causes increased airway responsiveness and asthma.
儿童下呼吸道感染，包括毛细支气管炎和支气管炎，常与反复喘息发作相关。不同的呼吸道病毒在儿童的不同年龄段具有不同的重要性。呼吸道合胞病毒是学龄前儿童中最常见的病毒性呼吸道感染，而鼻病毒在大龄儿童中的重要性日益增加。无症状病毒排出和轻度呼吸道感染不会引发哮喘症状，细菌也不会，除非与鼻窦炎相关。此外，流行病学研究强烈表明，幼儿期的病毒性下呼吸道疾病与肺部异常有关，包括支气管高反应性和外周气道阻塞，这些异常可能持续多年，并且可能是成年期慢性气道阻塞的一个原因。已经确定了几种呼吸道病毒引发哮喘的不同机制。然而，没有一种单一机制能充分解释病毒诱发的哮喘。尽管如此，这些各种提出的机制的一个共同主线是呼吸道病毒导致气道炎症的能力，要么直接通过细胞病变效应，要么间接通过增加呼吸道细胞的炎症过程。这些效应的结果导致气道反应性增加和哮喘。
