1 Introduction
Lipoid pneumonia(LP) is a rare disease caused by inhalation or aspiration of oily substances and has been reported with an incidence of only 1%~2.5% in autopsy series.1Based on the source of the lipid, LP is categorized as follows: Exogenous lipoid pneumonia(ELP), due to an episode of aspiration of a large quantity of a oil-based product; endogenous LP, related to uncommon medical conditions.2,3 Historically, Laughlen reported the first cases of exogenous lipoid pneumonia in one adult and in four children after chronic exposure to mineral oil nose drops and laxatives.4 Since then, most cases have been reported in patients with a predisposition to aspiration, such as mental retardation, cleft palate, anatomic or functional abnormality in swallowing.4-8 But, there have been some reports of exogenous LP caused by traditional folk remedies.9Various causative agents can cause LP, depending on local life style and cultural differences among patients.3,10,11 In China, kerosene, as a special kind of mineral oil for worship, has been reported as a common cause of exogenous LP.3,10
Due to lack of specific radiological features and manifestations of LP and awareness about this disease, diagnosis can be missed or delayed at the right time, which may lead to progress and unnecessary therapy.2,12 The nature history and outcome of LP are greatly variable mainly depending on the type, quantity, chemical properties and distribution of inhaled materials and are related to pulmonary tissue injury degree.13 At present , the treatment strategy for LP is not well defined in the literature and guildlines, but there is a concensus that the main measure is primarily supportive and generally conservative, and cease to exposure to the lipid substances. In 2020, a systematic review indicated that therapeutic lung lavage might be effective and safe treatment with long-term benefits for exogenous LP.12 In children patients with diffuse pulmonary lesion, aggressive therapy has been reported.7 However, therapy measures about the LP derives largely from case reports and case series, not long-term observational studies.12 In this study, we evaluated the radiological and clinical features of children LP patients used by therapeutic segmental bronchoalveolar lavage in combination with prednisolone.