Hill Walkers' Lung

A previously healthy female presented with a 7-week history of dyspnoea on exertion following inhalation of a fluorochemical-based water repellent spray, which was applied to footwear, in the living area that she shared with 8 members of her family while on a hill walking holiday. Clinical examination, serial lung function studies, bronchoalveolar lavage, transbronchial biopsies and high-resolution CT thorax confirmed a sub-acute interstitial pneumonitis, which did not resolve until 15 weeks following exposure. None of her family members were affected despite similar exposure. Interstitial pneumonitis due to inhalation of fluorochemical-based water repellent, though rarely described, usually presents in an acute severe form necessitating immediate therapy and resolves in 1-4 weeks. Pulmonary fibrosis can also occur. Sub-acute interstitial pneumonitis following inhalation of fluorochemical-based water repellent spray should always be considered as a cause of unexplained persistent respiratory symptoms in otherwise healthy individuals involved in outdoor pursuits.