Date Published: July 13, 2017
Publisher: Public Library of Science
Author(s): Esther Jiménez, Rebeca Arroyo, Nivia Cárdenas, María Marín, Pilar Serrano, Leonides Fernández, Juan M. Rodríguez, Hauke Smidt.
Many physicians, midwives and lactation consultants still believe that yeasts (particularly Candida spp.) play an important role as an agent of nipple and breast pain despite the absolute absence of scientific proofs to establish such association. In this context, the objective of this study was to investigate the microorganisms involved in sore nipples and/or painful “shooting” breastfeeding by using a variety of microscopy techniques, as well as culture-dependent and–independent identification methods. Initially, 60 women (30 diagnosed as suffering “mammary candidiasis” and 30 with no painful breastfeeding) were recruited to elucidate the role of their pumps on the milk microbial profiles. After realizing the bias introduced by using such devices, manual expression was selected as the collection method for the microbiological analysis of milk samples provided by 529 women with symptoms compatible with “mammary candidiasis”. Nipple swabs and nipple biopsy samples were also collected from the participating women. Results showed that the role played by yeasts in breast and nipple pain is, if any, marginal. In contrast, our results strongly support that coagulase-negative staphylococci and streptococci (mainly from the mitis and salivarius groups) are the agents responsible for such cases. As a consequence, and following the recommendations of the US Library of Medicine for the nomenclature of infectious diseases, the term “mammary candidiasis” or “nipple thrush” should be avoided when referring to such condition and replaced by “subacute mastitis”.
Lactation is probably the only bodily function for which modern medicine has almost no training, protocol or scientifically-acquired knowledge. When women suffer painful breastfeeding, they usually have to face the dilemma of continuing despite the pain or giving it up, preventing mothers and infants from getting the well-recognized health benefits associated to breastfeeding [1–3]. In practice, it is very unusual that they are offered the option of clinical tests (including milk analysis and antibiogram) in order to know the pain etiopathogenesis or to guide the therapeutic approach.
In 2002, Foxman et al.  published a highly influential epidemiological study on the occurrence of lactational mastitis among almost 1,000 breastfeeding women, in which the authors highlighted how little is known about the etiology and pathogenesis of this common condition.