Disseminated Varicella Pneumonia in an Adult with Substance Use History: Successful Critical Care Management in Resource Limited Settings.

Background: Varicella-zoster virus (VZV) infection is typically mild in children but can lead to severe, life-threatening complications in adults. Varicella pneumonia is among the most serious manifestations, with mortality rates reported up to 30-50% in critically ill patients. In low-resource settings such as Somalia, limited access to vaccination, antiviral therapy, and intensive care capacity increases the vulnerability of adults to disseminated disease. Case Presentation: We report a 30-year-old Somali male with a history of polysubstance use who developed disseminated primary varicella complicated by severe pneumonia and acute hypoxemic respiratory failure. He presented with a generalized vesicular rash and rapidly progressive dyspnea. Chest imaging demonstrated diffuse bilateral ground-glass opacities consistent with viral pneumonia. The patient required invasive mechanical ventilation and was treated with intravenous acyclovir and evidence-based supportive critical care. Despite severe hypoxemia on admission, he showed rapid clinical improvement, was extubated within 48 hours, and discharged in good condition. Full recovery was confirmed at one-month follow-up. Conclusion: Disseminated varicella pneumonia remains a potentially fatal condition in adults, particularly in countries without vaccination programs. This case demonstrates that prompt recognition, rapid initiation of antiviral therapy, and adherence to evidence-based critical care can lead to survival and recovery, even in fragile health systems. Preventive measures, including the introduction of vaccination and public health strategies targeting at-risk populations, remain essential to reduce the burden of severe varicella in Somalia and similar settings.