“Unexplained” Dyspnoea and Shrinking Lungs in Systemic Lupus Erythematosus

Abstract

A review of the respiratory-system changes in a series of 24 patients with S.L.E. has been made. This confirms previous reports of a high incidence of primary respiratory involvement in this condition. Breathlessness for no obvious cause occurred in one-third of the cases studied. Clinical, radiological, and physiological findings suggest that this dyspnoea is associated with a change in the mechanical properties of the lungs, which become small and stiff. The vital capacity is particularly reduced, and simple spirometry may be useful in the diagnosis of pulmonary involvement in S.L.E. and in following the response to treatment. It is suggested that the main pathological change is alveolar atelectasis. A tentative hypothesis to account for this is a deficiency of the surface-tension-reducing film that lines the alveoli of the normal aerated lung. © 1965, British Medical Journal Publishing Group. All rights reserved.