We have previously discussed my distrust of neonates (ALTE, BRUE) and this may be why so many of the Morsels focus on neonatal issues. Recently a dear friend, colleague, and full-time appreciator of UMMS Shock Trauma Pink Scrubs, Dr. Jessica Baxley brought up the topic of Mastitis in a Neonate! Is this another topic like Neonatal Conjunctivitis (something that seems simple, but is made complex by the fact it is in a neonate) or is it straight forward? Let us take a minute to review Neonatal Mastitis:

Neonatal Breast Enlargement

• Neonatal breast enlargement is a common and normal finding. [Masoodi, 2014]
  • At the end of pregnancy, the falling levels of estrogen can trigger a release of prolactin from the newborn’s pituitary.
  • Leads to breast enlargement in ~70% of neonates.

• Typically affects: [Masoodi, 2014]
  • Full Term infants (premature infants have less well developed breast tissue)
  • Both males and females equally.
  • Neonates during in the first week of life.
    • May last longer in females.

• Some will demonstrate discharge from the nipple.
  • This should be milky or clear fluid.
  • Often referred to as “Witch’s Milk” – but let us not be judgmental.

• The condition is self-limited and warrants only observation.
  • Observation for signs of developing infection.
  • Can become complicated by infection and abscess formation.

Neonatal Mastitis: Basics

• Mastitis, as the name would imply, is an infection of the breast tissue.
• Unlike normal breast enlargement in a neonate, mastitis will be: [Masoodi, 2014; Sloan, 2003]
  • Red
  • Painful
  • More likely in females (2:1)
  • Purulent discharge from nipple
  • Most often unilateral [Sloan, 2003]
  • Potentially associated with suppurative lesions elsewhere [Masoodi, 2014]

• Typically seen in 2nd – 8th week of life. [Masoodi, 2014; Ruwaili, 2012; Sloan, 2003]
  • Uncomplicated Mastitis is usually earlier (2nd – 3rd week).
  • Abscesses have been seen in 3rd and 4th week of life.

• It has been found to most often a localized process. [Masoodi, 2014]
  • Occurs in well appearing infants without systemic symptoms.
    • 8-28% have presented with systemic symptoms. [Masoodi, 2014; Sloan, 2003]
    • Fever, vomiting, lethargy or irritability are uncommon. [Ruwaili, 2012]
  • Blood cultures and CSF cultures, when done, have not proven to be positive in reported cases. [Masoodi, 2014; Ruwaili, 2012]

• Most often it is associated with S. aureus.
  • May also see Group B Strep, Gram-negative enteric, or anaerobic bacteria.

Neonatal Mastitis: Management

• 1st – Don’t call normal neonatal breast enlargement “mastitis.”
• 2nd – Don’t trust a neonate, but… 
• 3rd – Be reasonable though.
  • While remaining vigilant and not trusting the neonate, it has been well documented that neonates with isolated mastitis do well with limited work-up and antibiotics. [Masoodi, 2014; Ruwaili, 2012]
  • There is no standard approach with respect to “full-sepsis work-up” vs “limited-sepsis work-up.” [Ruwaili, 2012]
    • Not trusting the neonate, certainly warrants a more conservative approach, but again, this is usually localized pathology.
    • There is significant variation in physician’s management of mastitis. [Ruwaili, 2012]
  • There is also no standard approach with respect to IV antibiotics vs oral (Inpatient vs Outpatient). [Ruwaili, 2012]
    • Most studies to show a higher prevalence of inpatient IV antibiotics over outpatient management.
    • Oral antibiotics may have poor bioavailability in the neonatal period.
    • Personally, a neonate with a “suspected” infection makes me nervous… one with a KNOWN infection makes me diaphoretic.
  • The available evidence, though, would note that the non-toxic infant without systemic symptoms presenting with mastitis does not benefit from extensive testing. [Ruwaili, 2012]
  • Gram stain and Culture of any nipple discharge fluid will not likely help during the initial evaluation, but may be beneficial if there is treatment failure.
  • While abscesses typically require incision and drainage, there is evidence that trial of antibiotics is reasonable prior to either needle aspiration or incision and drainage of neonatal mastitis. [Sloan, 2003]

Moral of the Morsel

• Never trust a neonate. Just simply, never trust a neonate, but you can be reasonable.
• Breast enlargement in a neonate is normal. Breast infection is not. Mastitis requires antibiotics.
• If giving a neonate antibiotics, ask yourself whether you need to worry about disseminated infection.

References