OVERVIEW
Lipidoid pneumonia is a chronic inflammatory response of the lungs to some lipids. Interstitial pneumonia is caused by inhalation of milk, cod liver oil, or paraffin oil from the nose in premature, small, or cleft palate infants with inadequate pharyngeal reflexes.
Causes
1. Exogenous is caused by inhalation of greasy substances, commonly paraffin oil, cod liver oil, gasoline, milk, etc. Inhalation of vomitus usually contains animal oil, vegetable oil and pathogenic bacteria, which causes inflammation of the lungs and local tissue fibrosis.
2. Endogenous, also known as cholesterol pneumonia, is a chronic obstructive inflammation of the respiratory tract, such as chronic bronchitis, bronchodilatation, lung cancer and radiotherapy after the occasional complication, causing limited lesions in the lungs.
Symptoms
Most patients are asymptomatic, and it is only when an abnormality is detected on chest X-ray that attention is drawn to it. Common symptoms are cough, dyspnea after activity, chest pain, hemoptysis, fever (often low-grade), chills, night sweats and weight loss. Physical examination may show no signs. There may be fever, shortness of breath, turbidity on chest auscultation, bronchial or bronchoalveolar respiratory sounds, and dry or wet rales or twangs. Arterial blood gas analysis may be normal, and hypoxemia may occur after exercise. Severe patients may have hypoxemia, hypocapnia, and mild respiratory alkalosis.
Examination
1. Laboratory examination
Macrophages in sputum can be seen in vacuoles with a diameter of 5-50mm, which are collected into clusters, and when stained with Sudan, they are deep orange, with small extracellular oil droplets of the same staining, and accelerated blood sedimentation.
2. Other auxiliary examinations
X-ray chest film can be seen unilateral or bilateral infiltration shadow, limited or diffuse distribution, mostly seen in the lower lungs, air bronchial sign can be seen, the occurrence of fibrosis, lung volume reduction, linear and nodular infiltration shadow. There is also a limited mass shadow, which resembles bronchopulmonary carcinoma. Pulmonary function tests show restrictive ventilatory dysfunction and decreased lung compliance.
Diagnosis
The diagnosis of lipoid pneumonia relies on a detailed history; the presence of lipid-filled macrophages in the sputum is helpful.
Differential diagnosis
Massive shadows in the lungs can be identified by transfibrillographic lung biopsy, which can help to identify other causes of pulmonary fibrosis, and nodular mass shadows in the lungs, which must be differentiated from lung cancer.
Treatment
Instruct the patient to perform coughing exercises for several days to promote the elimination of mineral oil.
1. There is no specific treatment for exogenous lipoid pneumonia. Generally, symptomatic treatment should be given to stop cough, and antibiotics should be added in case of complication of infection.
2. Endogenous lipoid pneumonia should be treated for primary disease and symptomatic treatment. If necessary, surgery.