Clinical Presentation

Pathophysiology

Etiology

Omphalitis

Medical treatment

Antibiotics

Immediately start intravenous, broad-spectrum antibiotics at high doses. These should cover streptococci, staphylococci, Gram-negative rods and anaerobes.

 

Nutritional support is required from day one, owing to the high protein and fluid loss from the wound (similar to major burns). In severe cases, patients may need twice their basal calorie requirements. Nasogastric feeding may be helpful.

Intravenous immunoglobulin may be a useful adjunct in severe streptococcal infections (to neutralise streptococcal toxins).

Hyperbaric oxygen therapy for NF is controversial.

 

Omphalitis is an infection of the umbilical stump. Omphalitis typically presents as a superficial cellulitis that may spread to involve the entire abdominal wall and may progress to necrotizing fasciitis, myonecrosis, or systemic disease. Omphalitis is uncommon in industrialized countries; however, it remains a common cause of neonatal mortality in less developed areas.

It primarily affects neonates, in whom the combination of the umbilical stump and decreased immunity presents an opportunity for infection. It is rarely reported outside the neonatal period. Varieties of congenital conditions predispose to infection of the umbilical stump and are also among the differential diagnoses to consider for the presentation

Omphalitis is most commonly caused by bacteria. The most common bacteria are Staphylococcus aureus, group A Streptococcus, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis. The infection is typically caused by a mix of these organisms and is a mixed Gram-positive and Gram-negative infection. Anaerobic bacteria can also be involved. The predominant anaerobic isolates include Bacteroides fragilis, Peptostreptococcusbspecies, and Clostridium perfringens.

The umbilical stump represents a unique but universally acquired wound, in which devitalized tissue provides a medium that supports bacterial growth. Normally, the cord area is colonized with potential bacterial pathogens during or soon after birth. These bacteria have the potential to invade the umbilical stump, leading to omphalitis. If this occurs, the infection may progress beyond the subcutaneous tissues to involve fascial planes (necrotizing fasciitis), abdominal wall musculature (myonecrosis), and the umbilical and portal veins (phlebitis).

 

Like many bacterial infections, omphalitis is more common in those patients who have a weakened or deficient immune system or who are hospitalized and subject to invasive procedures. Therefore, infants who are premature, sick with other infections such as blood infection (sepsis) or pneumonia, or who have immune deficiencies are at greater risk. Infants with normal immune systems are at risk if they have had a prolonged birth, birth complicated by infection of the placenta (chorioamnionitis), or have had umbilical catheters.

 

Clinically, neonates with omphalitis present within the first two weeks of life with signs and symptoms of infection (cellulitis) around the umbilical stump (redness, warmth, swelling, pain), pus from the umbilical stump, fever, fast heart rate (tachycardia), low blood pressure (hypotension), somnolence, poor feeding, and yellow skin (jaundice). Omphalitis can quickly progress to sepsis and presents a potentially life-threatening infection. In fact, even in cases of omphalitis without evidence of more serious infection such as necrotizing fasciitis, mortality is high (in the 10% range).

Image 7.8 Periumbilical erythema in the patient with omphalitis.

Differential Diagnoses

The differential diagnoses of omphalitis (and specific features of each) include:

· umbilical granuloma (visible granuloma at the umbilicus);

· patent vitello-intestinal duct remnants - persistence of all or portions of the omphalomesenteric duct can result in fistulas, sinus tracts, cysts, congenital bands, and mucosal remnants (cystic swelling or fistulous opening with feculent matter discharging);

· patent urachus (fistulous opening with urine discharging) or urachal cyst;

· necrotising enterocolitis (abdominal distention, bilious vomiting, bloody stools);

· general sepsis;