eMedicine Specialties > Pediatrics: Cardiac Disease and Critical Care Medicine > Neonatology

Omphalitis

Author: Patrick G Gallagher, MD, Assistant Fellowship Program Director, Associate Professor, Department of Pediatrics, Division of Neonatal-Perinatal Medicine, Yale University and Yale-New Haven Children's Hospital
Coauthor(s): Samir S Shah, MD, Staff Physician, Departments of Pediatrics and Immunologic and Infectious Diseases, The Children's Hospital of Philadelphia
Contributor Information and Disclosures

Updated: Jan 16, 2009

Introduction

Background

Omphalitis is an infection of the umbilical stump.¹ 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. Omphalitis is predominantly a disease of the neonate. Only a few cases have been reported in adults.

Approximately three fourths of omphalitis cases are polymicrobial in origin. Aerobic bacteria are present in approximately 85% of infections, predominated by Staphylococcus aureus, group A Streptococcus, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis.^2,3 In the past, studies emphasized the importance of gram-positive organisms (eg, S aureus and group A Streptococcus) in the etiology of omphalitis. This was followed by a series of reports that highlighted the role of gram-negative organisms in the etiology of omphalitis. These studies suggested that the change in etiology may have been caused by the introduction of prophylactic umbilical cord care using antistaphylococcal agents, such as hexachlorophene and triple dye (a widely adopted practice in the 1960s), with a subsequent increase in gram-negative colonization of the umbilical stump.

Monitoring the microbial etiology of omphalitis is important, as recent trends have moved back to dry cord care without routine application of topical antiseptic agents. This trend has been widely accepted and is supported by the American Academy of Pediatrics (AAP), which supports dry cord care of the umbilicus after birth. Dry cord care leads to earlier separation of the cord after birth. It also leads to reports of wetter, odoriferous cords (described by some parents as nasty, smelly, or yucky) and higher, sometimes dramatic, colonization rates with S aureus and other bacteria.

Whether this increased colonization rate is, or will be, associated with higher rates of omphalitis or other neonatal infection is controversial. Some studies have suggested that higher colonization rates are associated with increased infection, whereas others have not. Discontinuation of routine application of topical agents may not be prudent in certain populations. A study from Nepal demonstrated that early chlorhexidine application reduced omphalitis and overall neonatal mortality.⁴

When techniques adequate for the recovery of anaerobic bacteria are used in studying newborns with omphalitis, anaerobes are recovered from one to two thirds of patients.^5,6 The predominant anaerobic isolates include Bacteroides fragilis, Peptostreptococcus species, and Clostridium perfringens. Several mothers whose newborns had omphalitis caused by B fragilis also had amnionitis caused by this organism. Isolated cases due to other anaerobic organisms, including Clostridium sordellii, also are reported. Neonatal tetanus (with or without omphalitis) caused by Clostridium tetani usually results from contamination of the umbilical cord during improperly managed deliveries outside of a medical facility or the cultural practice of placing cow dung on the umbilical stump after delivery. Neonatal tetanus is rare in the United States but is common in developing countries.

Pathophysiology

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). The factors that cause colonization to progress to infection are not well understood.

Frequency

International

Overall incidence varies from 0.2-0.7% in industrialized countries.⁷ Incidence is higher in hospitalized preterm infants than in full-term infants. Episodes of omphalitis are reported and are usually sporadic, but, rarely, epidemics occur (eg, due to S aureus or group A Streptococcus).^8,9,10

Mortality/Morbidity

Outcome is usually favorable in infants with uncomplicated omphalitis associated with cellulitis of the anterior abdominal wall. In a study by Sawin and colleagues, no deaths occurred among 32 infants with omphalitis in the absence of necrotizing fasciitis and myonecrosis.¹¹ The mortality rate among all infants with omphalitis, including those who develop complications, is estimated at 7-15%. The mortality rate is significantly higher (38-87%) after the development of necrotizing fasciitis or myonecrosis. Suggested risk factors for poor prognosis include male sex, prematurity or being small for gestational age, and septic delivery (including unplanned home delivery); however, data are limited and conclusions cannot be drawn regarding the role of these factors in the mortality rate.

Sequelae of omphalitis may be associated with significant morbidity and mortality, including necrotizing fasciitis, myonecrosis, sepsis, septic embolization, intra-abdominal complications, and death (see Complications).

Sex

No sex predilection has been reported, although males may have a worse prognosis than females.

Age

In full-term infants, the mean age at onset is 5-9 days. In preterm infants, the mean age at onset is 3-5 days.

Clinical

History

• A detailed review of the pregnancy, labor, delivery, and the neonatal course is important when assessing omphalitis. A history of poor feeding or feeding intolerance may be an early indication of infection. A history of change in mental status, such as irritability, lethargy, and somnolence, or a history of a decreased level of activity may be an important indicator of systemic dissemination of the infection.
• Anaerobic bacteria are part of the normal flora of the female genital tract and are commonly involved in ascending infections of the uterus and in septic complications of pregnancy; therefore, the higher incidence of omphalitis caused by anaerobes (especially B fragilis) in infants with adverse perinatal histories, such as premature or prolonged rupture of membranes and amnionitis, may relate to exposure to maternal infection.
• History of urine or stool discharge from the umbilicus suggests an underlying anatomic abnormality.

Physical

• Local disease: Physical signs vary with the extent of disease. Signs of localized infection include the following:
  • Purulent or malodorous discharge from the umbilical stump
  • Periumbilical erythema (Recently, algorithms that attempt to standardize the clinical diagnosis of omphalitis have been developed, emphasizing extent of periumbilical erythema and absence or presence of pus.)
  • Edema
  • Tenderness
• Extensive local disease, with extension: The following signs indicate more extensive local disease, such as necrotizing fasciitis or myonecrosis, which are typically found in a periumbilical location but may spread across the abdominal wall, onto the flanks and back, and into the scrotum. These signs may also suggest infection by both aerobic and anaerobic organisms and include the following:
  • Ecchymoses, violaceous discoloration
  • Bullae
  • Peau d'orange appearance
  • Crepitus
  • Petechiae
  • Progression of cellulitis despite antimicrobial therapy
• Systemic disease: Signs of sepsis or other systemic disease are nonspecific and include disturbances of thermoregulation or evidence of dysfunction of multiple organ systems. Examples include the following:
  • Disturbances of thermoregulation - Fever (temperature >38°C), hypothermia (temperature <36°C), or temperature instability
  • Cardiovascular disturbances - Tachycardia (pulse >180 beats per minute [bpm]), hypotension (systolic blood pressure <60 mm Hg in full-term infants), or delayed capillary refill (<2-3 s)
  • Respiratory disturbances - Apnea, tachypnea (respirations >60/min), grunting, flaring of the alae nasi, intercostal or subcostal retractions, or hypoxemia
  • GI tract disturbances - Rigid or distended abdomen or absent bowel sounds
  • Cutaneous abnormalities - Jaundice, petechiae, or cyanosis
  • Neurologic abnormalities - Irritability, lethargy, weak sucking, hypotonia, or hypertonia

Causes

• Omphalitis is a polymicrobial infection typically caused by a mixture of aerobic and anaerobic organisms. Associated risk factors include the following:
  • Low birth weight (<2500 g)
  • Prior umbilical catheterization
  • Septic delivery (as suggested by premature rupture of membranes, nonsterile delivery, or maternal infection)
  • Prolonged rupture of membranes
• Omphalitis occasionally manifests from an underlying immunologic disorder.¹² Leukocyte adhesion deficiency (LAD) is most prominent among the immunodeficiency syndromes.^13,14,15,16 Numerous infants with acute or chronic omphalitis have been diagnosed with LAD, a rare immunologic disorder with an autosomal recessive pattern of inheritance. These infants typically present with the following:
  • Leukocytosis
  • Delayed separation of the umbilical cord, with or without omphalitis
  • Recurrent infections
• Omphalitis may also be the initial manifestation of neutropenia in the neonate.^17,18,19 Infants with neonatal alloimmune neutropenia have presented with omphalitis. Neonatal alloimmune neutropenia is a disease analogous to Rh-hemolytic disease and results from maternal sensitization to fetal neutrophils bearing antigens that differ from the mother's. Maternal immunoglobulin G antibodies cross the placenta and result in an immune-mediated neutropenia that can be severe and last for several weeks to 6 months. Affected infants may present with other cutaneous infections, pneumonia, sepsis, and meningitis. Since omphalitis complicated by sepsis also can be associated with neutropenia, the underlying immune-mediated neutrophil destruction may not be immediately appreciated in affected newborns.
• Rarely, an anatomic abnormality such as a patent urachus, patent omphalomesenteric duct, or urachal cyst may be present.^{20,21,22,23,24}

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