Omphalitis is a soft tissue infection involving the umbilicus and surrounding tissues with redness and induration around the umbilical stump. Risk factors include: prematurity, prolonged rupture of membranes, maternal infection, low birth weight, history of umbilical catheter and home birth. Pathogens include Staph, Strep and Gram Negative bacteria. Studies have shown that bacteremia can be present in up to 13% of cases.
Omphalitis most often occurs in infants 8-22 days. If fever is present, the AAP guidelines for neonatal fever should be followed. In the well appearing, afebrile infant, blood cultures should be obtained, but CSF studies are not reflexively indicated. Since urachal anomalies can be present in up to 1/4 of these patients, urine studies should be obtained and an ultrasound can be considered if drainage is present. A surface culture should be obtained when possible as well.
Kaplin, Ron. Clinical Presentation and Approach to Evaluation and Management. Pediatric Emergency Care 2023; 39(3):188-189.