Swelling around the umbilicus, oozing with a foul odor, which may be purulent or mixed with blood are all symptoms of the clinical diagnosis of umbilical infection. What are the causes of periumbilical swelling? Here’s a look. Causes 1, causative agent Umbilical cord inflammation causative agent to staphylococcus is the most common, followed by Escherichia coli and hemolytic streptococcus and so on. It is reported that the main causative organism of socially acquired infections is gram-positive cocci (67.2%); while gram-negative bacilli are the main causative organisms in hospital-acquired infections (56.8%). 2, the cause of infection (1) acute umbilical cord infection: ① neonatal umbilical cord infection: the main causes of umbilical cord infection in newborns are: postnatal ligation of the umbilical cord contamination or before and after the umbilical cord off the dressings by feces, urine pollution; premature rupture of the amniotic membrane, the umbilical cord before birth is contaminated; umbilical cord during labor and delivery by the bacteria contamination; by the umbilical-urinary fistula or yolk fistula effluent contamination; secondary to umbilical velvet or sinus of the umbilical cord infection. (2) adult umbilical infection: umbilical fossa deeper and the bottom surface of the skin folds, dirt, sebum retention, it is not easy to make the local clean, or to remove the dirt accidentally abrasion, resulting in bacterial invasion and cause infection. (2) Chronic umbilical cord infection: acute umbilical cord infection is not cured, and it can be extended to chronic umbilical cord infection and umbilical cord granuloma; the umbilical cord falls off prematurely and leaves unhealed wounds; there are foreign objects (such as talcum powder) in the umbilical cord nest for long-term chronic stimulation, which can cause prolonged umbilical cord inflammation and the formation of umbilical cord granuloma.