Neonatal varicella complicated by Staphylococcus aureus lung abscess in a preterm infant: a case report.

Background: Neonatal varicella is a rare but potentially life-threatening condition, particularly in preterm infants. Although secondary bacterial infections are common complications, deep organ involvement such as lung abscess formation is exceedingly rare. Reports describing neonatal varicella complicated by Staphylococcus aureus lung abscess are scarce. Case presentation: We report a 26-day-old preterm infant (32 weeks' gestation, birth weight 1.94 kg) who developed a progressive vesiculopustular skin lesions and respiratory deterioration following exposure to maternal varicella. Despite initial topical treatment, the rash rapidly worsened and was accompanied by poor responsiveness, apnea, cyanosis, and hypothermia. On admission, the infant presented with extensive skin lesions, respiratory distress requiring non-invasive ventilation, coagulopathy, and thrombocytopenia. Intravenous acyclovir and immunoglobulin were initiated. Although the skin lesions gradually crusted and resolved, respiratory abnormalities persisted and oxygen supplementation remained necessary. Chest imaging subsequently revealed a right upper lobe abscess. Blood cultures remained negative; however, respiratory metagenomic next-generation sequencing (mNGS) identified Conclusions: This case represents a rare presentation of neonatal varicella complicated by