Imaging description

This two and a half-month-old female infant presented with persistent tachypnea and abnormal chest radiographs with no response to antibiotics. Frontal and lateral chest radiographs over a two-month period demonstrated persistent patchy bilateral upper and lower confluent opacities, predominantly perihilar and posterior on the lateral view (Fig. 11.1a–c). A contrast-enhanced CT scan demonstrated low-density confluent consolidation in a perihilar and posterior distribution (Fig. 11.1d, e). On the basis of the combination of prolonged mild clinical symptoms and the location and appearance of the consolidated lung, the possibility of chronic lipoid pneumonia was raised. The family was questioned and confirmed that they adhered to a Hispanic cultural practice of giving the baby a teaspoonful of olive oil daily as a general health booster. The baby underwent bronchoalveolar lavage (BAL), which yielded milky fluid containing many lipid-laden macrophages typical of lipoid pneumonia; no organisms were present.

Importance

Oral administration of various oils is a relatively common cultural practice; these include mineral oil, olive oil, shark liver oil, cod liver oil, coconut oil, and ghee. These materials are poorly handled by the swallowing mechanism of infants or older children with swallowing dysfunction and readily slide into the airway, often without eliciting a cough reflex. They are poorly removed by cilia and accumulate in the distal airways and alveoli, producing consolidation and surrounding local inflammatory response. The diagnosis is often very delayed as parents are usually not aware of the harmful effects of these agents and physicians rarely think to question this practice in a child with respiratory symptoms. Key imaging findings are marked radiographic findings in the face of mild clinical distress as well as the perihilar and posterior distribution of consolidation, typical of aspiration. Low-density consolidation on CT is a suggestive imaging finding but is quite uncommonly present due to the accompanying inflammatory response which masks the low-density lipid. Patchy confluent opacity is often surrounded by ground glass opacity, similar to other consolidative processes. Prominent interlobular septal thickening has also been described in children with lipoid pneumonia.