[Hypersensitivity pneumonitis presenting as acute respiratory distress syndrome]

Hypersensitivity pneumonitis (HP) are typically subacute in their presentation and the diagnosis may be difficult.

We report a case of a hypersensitivity pneumonitis in a 27-years-old woman, caused by exposure to mould in an insalubrious mobile home. The initial presentation was with acute respiratory distress syndrome complicating RSV pneumonia, treated with ribavirin and corticosteroids in winter 2013-2014. The diagnosis of hypersensitivity pneumonitis was based on clinical and radiological relapse occurring during winter 2014-2015 with confirmed exposure to antigen with fungal sampling at home, respiratory deterioration with antigen rechallenge and a compatible chest CT-scan.

The diagnosis of hypersensitivity pneumonitis should be considered in similar cases. Treatment is based mainly on removing exposure to the causative antigen.