Introduction There is considerable overlap between the clinical manifestations of covid-19 pneumonia and the acute interstitial lung disease seen in certain rheumatic disorders. In addition, pulmonary fibrosis is increasingly recognised as a potentially serious consequence of both. Methods This review explores this overlap of clinical features, risk factors and causation, offering insights into the immune mechanisms that contribute to both sets of disorders. Results The therapeutic role of immunosuppression and biologic agents in the treatment of covid-19 is explained in the light of this. Discussion We propose how lessons learned from the insights recently gained into each disorder can improve our insight into immunological mechanisms and application of therapeutic interventions in the other.