Case Presentation: An 86-year-old female with a history of atrial fibrillation, hyperlipidemia, and recurrent pneumonia presented with worsening dyspnea, productive cough, and significant oxygen dependency. CT imaging revealed bilateral dense consolidations and nodular infiltrates, raising suspicion for malignancy, cryptogenic organizing pneumonia, or aspiration-related pathology. Despite broad-spectrum antibiotics and steroids, her clinical condition remained refractory. Bronchoscopy with bronchoalveolar lavage (BAL) and transbronchial biopsy showed atypical cells with viral cytopathic changes consistent with HSV pneumonitis. Immunohistochemical staining confirmed HSV-1 and HSV-2 positivity. The patient was managed with valacyclovir, leading to gradual clinical improvement, reduced oxygen requirements, and radiographic resolution.
Discussion: HSV pneumonitis, though rare, should be considered in cases of refractory bilateral infiltrates and non-resolving pneumonia. The condition is pathologically associated with direct viral cytotoxicity and secondary immune-mediated lung damage. Prompt diagnosis requires invasive procedures such as bronchoscopy and cytology, which can reveal hallmark findings like multinucleated cells and intranuclear inclusions. Antiviral therapy, particularly with acyclovir or valacyclovir, is essential, with adjunctive treatments addressing co-infections or inflammatory sequelae.In this case, the patient’s pulmonary pathology was complicated by concurrent Stenotrophomonas maltophilia infection and fungal colonization, highlighting the need for comprehensive microbiological evaluation. Multidisciplinary management involving infectious disease, pulmonology, and critical care ensured tailored therapeutic interventions.
Conclusions: This case demonstrates the diagnostic and therapeutic complexities of managing bilateral pulmonary infiltrates caused by rare Herpes Simplex Virus (HSV) pneumonitis. The patient’s presentation with hypoxemic respiratory failure and non-resolving infiltrates initially suggested more common conditions like bacterial pneumonia, malignancy, or inflammatory lung disease. HSV in the lungs can cause necrotizing pneumonitis, characterized by alveolar hemorrhage, necrosis, and cytopathic changes such as multinucleation and eosinophilic inclusions. Its diagnosis hinges on cytological evaluation, HSV PCR, or immunohistochemical staining. Risk factors include advanced age, underlying chronic diseases, and, occasionally, unrecognized immune dysfunction. Definitive diagnosis in this case was achieved through bronchoscopy and cytological analysis, revealing HSV as the underlying cause. HSV pneumonitis, though rare, must be considered in patients with persistent pulmonary infiltrates unresponsive to standard treatments. Early antiviral therapy, as demonstrated here, can lead to clinical and radiographic improvement, even with co-infections and complicating factors. This case highlights the importance of a multidisciplinary approach involving pulmonology, infectious disease, and critical care teams in managing complex respiratory failure. It also reinforces the need to consider less common etiologies like HSV pneumonitis in persistent pulmonary infiltrates to ensure accurate and timely treatment, improving outcomes.
