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Lipoid pneumonia is a pneumonitis resulting from the aspiration of lipids, and is commonly associated with the use of mineral oil as a laxative. Lipoid pneumonia is relatively unfamiliar to clinicians and is probably underdiagnosed. OBJECTIVES: To increase physicians' awareness of Lipoid pneumonia, its diagnosis and prevention. METHODS: We present two illustrative cases of Lipoid pneumonia and review the literature. RESULTS: Two cases of Lipoid pneumonia were diagnosed within half a year in an internal medicine ward. Both cases were elderly patients, and Lipoid pneumonia was associated with the use of mineral oil as a laxative agent. Computerized tomography revealed bilateral low attenuation infiltrates, associated with a "crazy paving" pattern in one case. Sudan Black staining was diagnostic in both cases--in one on a transbronchial biopsy specimen, and in the other on sputum cytologic examination. Both patients suffered from neurologic diseases and were at risk of aspiration. In both cases clinical symptoms and signs continued for several months prior to diagnosis but resolved after the mineral oil was discontinued. CONCLUSIONS: Lipoid pneumonia often occurs in elderly patients who are at risk of aspiration. The condition may be underdiagnosed. Since in most cases mineral oil cathartics are the causative agent, an effort at primary prevention is indicated. It is suggested that the licensing of mineral oil for internal use be changed.
Exogenous lipoid pneumonia refers to lung lesions that develop following aspiration or inhalation of animal, vegetable, or mineral oils. An engaging account of the circumstances under which aspiration of lipoid material occurs is found in the reference by Spickard and Hirschmann. Lipoid material glides down the respiratory tract without stimulating cough and is not removed effectively by the cilia. Animal fats, which can be hydrolyzed to fatty acids cause more inflammation than vegetable or mineral oils, but all types stimulate a chronic granulomatous inflammation, which tends to be located in the lower or middle lobes.
Exogenous lipoid pneumonia is an uncommon condition resulting from aspirating or inhaling fatlike material, such as mineral oil found in laxatives and various aerosolized industrial materials. These substances elicit a foreign body reaction and proliferative fibrosis in the lung. Because symptoms are absent or nonspecific and the roentgenographic findings simulate other diseases, exogenous lipoid pneumonia is often unrecognized. Yet, appropriate historical inquiries and simple laboratory tests can lead to the correct diagnosis, removal of the offending agent, and, potentially, improvement in lung function before serious complications develop.
Although a rare form of nonresolving pulmonary infiltrate, exogenous lipoid pneumonia is a great mimicker. It often is mistaken for bacterial pneumonia or cancer. Many cases have been diagnosed only by open lung biopsy or other invasive procedures. Depending on the type of lipid ingested and the degree of inflammation that occurs, damage to the lung can be little to none or can fulminate to necrosis and hemorrhage. Symptoms may range from none to respiratory failure. In the case presented, the patient was ingesting Vaseline Intensive Care Lotion and baby oil as laxatives. This information was elicited only after diagnosis was made by open lung biopsy.
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Lipoid Pneumonia Symptoms
Lipoid Pneumonia Diagnosis and Treatment
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