A Fatal Case of Herpes Simplex Pneumonia in an Immunocompetent Patient

Abstract

Herpes pneumonia, or active infection of pulmonary tissue by Herpes Simplex Virus type-1 (HSV), is a rare condition, usually observed in immunocompromised individuals. We present a rare case of HSV pneumonia that was complicated by a pneumothorax, ultimately proving fatal in an elderly, immunocompetent individual. Case Description: An 82year-old male with a history of chronic obstructive pulmonary disease and hypothyroidism presented to our facility with acute respiratory failure requiring mechanical ventilation. Computed Tomography (CT) scan of the thorax demonstrated diffuse bilateral ground glass opacities, and consolidative changes. Broad spectrum antibacterial coverage and high dose steroids were initiated. Blood and tracheal aspirate bacterial and fungal cultures did not yield any growth. A bronchoscopy, performed to better characterize his pulmonary pathology, demonstrated diffuse airway erythema and secretions. Immunoglobulin G (IgG) to Herpes Simplex Virus (HSV) Type 1 was detected on bronchoalveolar lavage (BAL) sample; additionally, HSV-1 was isolated on viral culture. Histopathological analysis of BAL sample was notable for viral inclusion bodies (figure 1). Additional testing for cytomegalovirus, epstein-barr virus, human immunodeficiency virus (HIV), hepatitis viruses, tuberculosis, mycoplasma, legionella and cryptococcus was negative. Acyclovir was initiated, with subsequent clinical improvement and reduction in ventilation requirements. The patient was extubated, but his hospital course was complicated by a large left sided pneumothorax. Following a discussion regarding goals of care, comfort care measures were instituted, with demise following shortly thereafter. Discussion: HSV pneumonia is an uncommon respiratory infection that is usually seen in association with immunocompromising conditions such as Systemic Lupus Erythematosus 1 , Chronic Lymphocytic Leukemia 2 , and HIV infection. 3 There are scarce published reports about the occurrence of this infection in immunocompetent patients. [4][5][6] HSV has been known to be a contaminating agent in the respiratory tract of ventilated patients. 7 However, the presence of a clinical picture consistent with viral pneumonitis, with ground glass opacities, detection of viral on BAL polymerase chase reaction, and intranuclear inclusion bodies on histopathological analysis of BAL sample are indicators of active infection. 8 Clinically, our patient responded to acyclovir, further lending credence to the probability of our diagnosis of HSV pneumonia. Unfortunately, the clinical course was complicated by a pneumothorax, which is a rare complication of HSV pneumonia, only one other case was found. 9 Our case demonstrates that herpes pneumonitis can affect the immunocompetent, and can be associated with a pneumothorax. HSV infection should be considered in patients with pneumonia who fail to respond to antibacterial therapy.