Maternal Mastitis

Mastitis is an inflammation of the breast that, if mishandled, can end up becoming infected. When there is infection, the most frequently implicated germ is Staphylococcus aureus ^{(Cullinane 2022, Paricio 2017, Amir 2016, Espinola 2016, Baeza 2015, Amir 2014, Spencer 2008)}.

Coagulase negative staphylococci (CoNS) such as S. epidermidis are not associated with mastitis ^{(Culinane 2022)}. There is also no evidence that bacterial biofilms are a cause of blocked ducts and mastitis. ^{(Douglas 2022)}. Studies are needed to determine the aetiological role of Candida albicans, which appears to be a minority. ^{(Amir 2014, Hanna 2011, Carmichael 2002, Brent 2001)}

Damaged nipple, infrequent feedings, scheduled frequency or duration of feedings, missed feedings and poor latch are risk factors for mastitis. ^{(Wilson 2020, Amir 2014)}

Effective treatment requires resting of the mother, a frequent emptying of the breast, use of anti-inflammatory drugs and in case of no amelioration, it should be necessary a course of antibiotics that must be effectively active against Staphylococcus aureus. ^{(Paricio 2017, Espinola 2016, Amir 2014, Cabou 2011, Spencer 2008)}. High-quality double-blind RCTs are needed to determine the use of antibiotics in mastitis. ^{(Jahanfar 2013)}

The nursing infant may be latched on to the inflamed breast without bad consequences for the child ^{(Amir 2014, Lawrence 2013, WHO 2000)}. Emptying of the breast is important for treatment, with the baby being the most effective extractor. Better results are obtained with a continued lactation during the treatment with antibiotics. Incidentally, the baby may refuse sucking the breast because a salted flavor of the milk, in which case, it should be manually or mechanically pumped.

Medication used for the treatment of mastitis, such as antibiotics and anti-inflammatory drugs, is compatible with breastfeeding.

Breast milk culture is only indicated if ^{(Paricio 2017, Espínola 2016, Amir 2014)}: 

• no response to antibiotic therapy within 48 hours
• return or recurrence of mastitis
• nosocomial mastitis (hospital-acquired)
• patient allergic to beta-lactam antibiotics
• population with excessive frequency of methicillin-resistant Staphylococcus isolates
• serious or unusual case of entry
• Late or recurrent group B streptococcal infection in the breastfed infant

As of the last review, there is no valid scientific evidence that the use of probiotics is effective in treating mastitis or breast pain in women ^{(WHO 2022, Crepinsek 2020, Barker 2020, Paricio 2017, Espínola 2016, Amir 2016, Baeza 2015, Amir 2014)}. Its indiscriminate use can delay other treatments and be financially burdensome ^{(WHO 2022, Amir 2016)}.Evidence that orally administered can get into the milk is lacking. ^{(Elias 2011)}

The use of presumably preventive probiotics during pregnancy was associated with an increased risk of mastitis and other complications of breastfeeding during the first month of breastfeeding. ^{(Karlsson 2019)}

Only in the rare case of tuberculosis mastitis are both direct breastfeeding and the administration of expressed milk contraindicated. ^{(Red Book 2021-24 p.110)}

Group B Streptococcus agalactiae (GBS) in breast milk ^{(Nicolini 2018, Zimmermann 2017, Filleron 2014, Davanzo 2013, Kotiw 2003, Rench 1989)}:

GBS can be isolated in breast milk from healthy, mastitis-free women.

The pathogenesis of late onset and/or recurrent GBS infection (sepsis-meningitis) in the infant and its relationship to the occurrence of GBS in breast milk is unclear. Several authors advocate a retrograde and circular mechanism of infection: GBS from the oral mucosa of the late-infected infant (by contamination during delivery or by subsequent infection from other sources outside or not from the mother) would colonize milk and breast tissue, causing an increase of GBS colonies in breast milk and making possible the appearance of recurrent GBS infection in the infant and an increased risk of mastitis occurrence.

Milk culture is indicated in case of late or recurrent GBS infection in an infant and to treat or not to treat asymptomatic mothers depending on the GBS bacterial load found. Suspending lactation could favor the development of mastitis or complications such as abscess.

Suspension of breastfeeding would only be indicated in the case of high-risk preterm infants admitted to the ICU and in the case of recurrent infection of the infant; until milk cultures were negative for GBS, pasteurized breast milk could be fed. ^{(Davanzo 2013)}

See below the information of these related products:

• Cefadroxil (Safe substance and/or breastfeeding is the best option.)
• Cephalexin (Safe substance and/or breastfeeding is the best option.)
• Cloxacillin; Cloxacillin Sodium (Safe substance and/or breastfeeding is the best option.)
• Ibuprofen (Safe substance and/or breastfeeding is the best option.)
• Paracetamol (Safe substance and/or breastfeeding is the best option.)
• Probiotics (Fairly safe. Mild or unlikely adverse effects. Compatible under certain circumstances. Follow-up recommended. Read Commentary.)