Post-cesarean Sepsis Secondary to Vernix Caseosa Peritonitis: A Diagnostic Challenge With Misleading Imaging

Vernix caseosa peritonitis is an uncommon but important cause of postoperative intra-abdominal sepsis following cesarean delivery, resulting from a sustained foreign body inflammatory reaction to fetal vernix introduced into the maternal peritoneal cavity, typically manifesting within hours to days after surgery and often mimicking other acute surgical abdominal conditions with non-specific or misleading radiological findings. We report the case of a 43-year-old woman who presented five days after an uncomplicated cesarean section with severe abdominal pain, vomiting, and markedly elevated inflammatory markers, in whom initial computed tomography of the abdomen and pelvis suggested enteritis with associated free intraperitoneal fluid, without the characteristic features of vernix caseosa peritonitis. Despite broad-spectrum intravenous antibiotics, her condition deteriorated with the development of progressive pelvic collections requiring surgical intervention, and intraoperative findings revealed multiple yellow patches on the serosal surfaces of visceral organs consistent with vernix caseosa peritonitis, with the diagnosis subsequently confirmed on histopathological examination. This case highlights the significant diagnostic challenge posed by this rare entity and underscores the importance of maintaining a high index of clinical suspicion in patients presenting with peritonitis following cesarean delivery, as timely surgical source control via laparotomy and peritoneal lavage remains the cornerstone of management.