Isolated Submandibular Sialadenitis in a Preterm Neonate: A Rare Cause of Neck Swelling

Sialadenitis is an infection or inflammation of the salivary glands and can be caused by bacteria, viruses, or obstruction, with Staphylococcus aureus being the primary cause. Risk factors for neonatal sialadenitis include prematurity, immunological immaturity, dehydration, tube feeding, and factors predisposing to bacterial colonization. Symptoms may manifest as localized swelling, systemic signs of infection, or respiratory instability in preterm neonates. Isolated submandibular sialadenitis is extremely rare, with only a few cases reported in the medical literature. We report a case of a preterm neonate with isolated submandibular sialadenitis, in which culture and swabs were negative, but ultrasound findings suggested infection of the submandibular gland. Ultrasound played a key role in diagnosis, as serial scans in this case confirmed sialadenitis and guided treatment. The patient received intravenous flucloxacillin, gentamicin, and metronidazole, resulting in complete resolution of the swelling. Early treatment is crucial to prevent serious complications. Awareness of this rare condition can prevent delayed diagnosis and reduce the risk of serious complications.