Acute herpes simplex virus 1 pneumonitis in a patient with systemic lupus erythematosus.

A woman with severe and longstanding systemic lupus erythematosus presented with a 1-week history of fever up to 38°C and pain in her right flank. Computed tomography scan of the chest revealed interstitial infiltrates and multiple nodules. Bronchoalveolar lavage did not show any inflammatory cells. Gram stain and cultures for aerobic and anaerobic bacteria, fungi, and Nocardia; acid-fast staining; polymerase chain reaction for tuberculosis, cytomegalovirus, herpesvirus 6, and parvovirus B19; and IF staining for pneumocystic and Legionella antigen were all negative. Transbronchial biopsy was nondiagnostic. Open lung biopsy with polymerase chain reaction and immunohistochemistry analyses revealed herpes simplex virus 1 infection. Acyclovir therapy was initiated and was followed by significant improvement. Herpes simplex virus 1 infection (although unusual) should be considered in patients with systemic lupus erythematosus with an atypical clinical presentation.