Neonatal mastitis due to Escherichia coli

Mastitis in early infancy

AIM

To evaluate the clinical features and microbiological findings in young infants with mastitis.

METHODS

Retrospective review of medical records of 18 infants with breast inflammation during the first 3 mo of life seen in the paediatric emergency department between 1992 and 2002.

RESULTS

All were full-term infants with female-male ratio of 3.5:1. The age ranged from 12 to 45 d, with a peak in the 4th and 5th weeks of life. Only five patients had systemic manifestations, and five were pretreated with oral antibiotics (amoxicillin-clavulanic acid). The latter as well as seven additional cases required incision and drainage due to abscess formation. Bacterial cultures grew Staphylococcus aureus in 10 cases including all pretreated infants. In four of these cases, Gram stain showed the pathogen. After antimicrobial treatment, no recurrence was observed in any of the patients.

CONCLUSIONS

These findings suggest that mastitis in early infancy should be treated with parenteral antibiotics guided by Gram stain when available and informative. Otherwise, beta-lactamase-resistant antibiotics are a reasonable empirical initial treatment pending culture results. Optimizing the management of infants with mastitis is important especially since abscess formation requiring incision may be detrimental for later breast development.

Cutaneous and subcutaneous infections in newborns due to anaerobic bacteria

This review describes the microbiology and management of the major cutaneous and subcutaneous infections in newborns where anaerobic bacteria predominate: omphalitis, necrotizing fasciitis, breast abscess, and scalp infection following intrauterine fetal monitoring. The predominant bacteria known to cause these infections are group B streptococcus, group D enterococcus, group A streptococcus, Staphylococcus aureus, Enterobacteriaceae, and anaerobic bacteria. All of these agents can colonize or infect the mother and subsequently colonize or infect the fetus or newborn either intrauterinely or during the passage through the birth canal. Infections due to anaerobes are often polymicrobial, and include also aerobic and facultative bacteria. The anaerobes recovered from these infections are Bacteroided fragilis group, Fusobacterium spp., Peptostreptococcus spp. and Clostridium spp. Early recognition and effective medical and surgical therapy are essential to recovery. Managements of these infections include surgical debridement and drainage when appropriate as well as topical and systemic use of antimicrobial agents effective against both aerobic and anaerobic bacteria.

Subclinical mastitis presenting as acute, unexplained, excessive crying in an afebrile 31-day-old female

We present a case of a 31-day-old female who presented with an acute, unexplained, episode of excessive crying. The patient had no history of fever and no fever on presentation. There was no evidence of skin erythema or swelling on presentation. Chest radiograph and computed tomography of the head were normal. Urinalysis and cerebral spinal fluid analysis were normal. The white blood cell count was within normal limits (17,400 cells/mm3). It was not until 6 hours after the onset of inconsolable crying (2.5 hours after presentation to the emergency department) that the patient's temperature rose to 38.5 degrees C (101.3 degrees F). Clinical signs of mastitis did not become appreciable until the 2nd hospital day. We review the literature on infantile mastitis and acute, unexplained, excessive crying. The importance of a thorough, conservative approach to the infant with acute, unexplained, excessive crying is discussed.

Neonatal mastitis

Forty-one cases of neonatal mastitis seen at Children's Hospital, Boston since 1947 have been analyzed and the literature since 1950 reviewed. All 41, like those in the literature, occurred in full-term infants 1-5 weeks of age, with a sex ratio of 2:1 (females:males). Bilaterality was rare (3) cases in this series, one in the literature review) and systemic spread or extramammary foci even rarer. The incidence has changed little in the past 35 years except for the larger number of cases in the 1950s. In the present series, all but a few cases have been caused by Staphylococcus aureus, and gram-negative enteric bacilli have not been seen. Therapy is surgical incision and drainage when fluctuance is present, but early treatment with appropriate intravenous antibiotics has apparently obviated the need for surgery in many recent cases. The prognosis for cure of the infection is excellent.