Waterproofing spray-associated pneumonitis review: Comparison with acute eosinophilic pneumonia and hypersensitivity pneumonitis

The Underlying Mechanism of Poisoning after the Accidental Inhalation of Aerosolised Waterproofing Spray

Waterproofing sprays can cause acute respiratory symptoms after inhalation, including coughing and dyspnoea shortly after use. Here, we describe two cases where persons used the same brand of waterproofing spray product. In both cases the persons followed the instructions on the product and maximized the ventilation by opening windows and doors; however, they still became affected during the application of the product. Products with the same batch number as that used in one case were tested for their effect on respiration patterns of mice in whole-body plethysmographs and lung surfactant function inhibition in vitro. The product was used in spraying experiments to determine the particle size distribution of the aerosol, both using a can from one case and a can with an identical batch number. In addition, the aerosols in the mouse exposure chamber were measured. Aerosol data from a small-scale exposure chamber and data on the physical and temporal dimensions of the spraying during one case were used to estimate the deposited dose during the spraying events. All collected data point to the spraying of the waterproofing product being the reason that two people became ill, and that the inhibition of lung surfactant function was a key component of this illness.

An Autopsy Case of An Acute Exacerbation of Idiopathic Pulmonary Fibrosis Triggered by the Inhalation of a Waterproofing Spray

An 82-year-old Japanese man with idiopathic pulmonary fibrosis (IPF) experienced dyspnea after using a waterproofing spray in a closed room. He presented with hypoxemia and his chest computed tomography showed additive bilateral diffuse ground-glass attenuation on fibrosis, which was diagnostic of an acute exacerbation of IPF (AE-IPF). Combined treatment with high-dose corticosteroids and immunosuppressants were ineffective, and he later died of respiratory failure. Autopsy findings showed diffuse alveolar damage with honeycombing. His medical history and autopsy histopathology suggested AE-IPF caused by the inhalation of a waterproofing spray.