Re-thinking benign inflammation of the lactating breast: Classification, prevention, and management

Abstract

Despite the known benefits of breastfeeding for both infant and mother, clinical support for problems such as benign inflammation of the lactating breast remain a research frontier. Breast pain associated with inflammation is a common reason for premature weaning. Multiple diagnoses are used for benign inflammatory conditions of the lactating breast which lack agreed or evidence-based aetiology, definitions, and treatment. This article is the second in a three-part series. This second review analyses the heterogeneous research literature concerning benign lactation-related breast inflammation from the perspectives of the mechanobiological model and complexity science, to re-think classification, prevention, and management of lactation-related breast inflammation. Benign lactation-related breast inflammation is a spectrum condition, either localized or generalized. Acute benign lactation-related breast inflammation includes engorgement and the commonly used but poorly defined diagnoses of blocked ducts, phlegmon, mammary candidiasis, subacute mastitis, and mastitis. End-stage (non-malignant) lactation-related breast inflammation presents as the active inflammations of abscess, fistula, and septicaemia, and the inactive condition of a galactocoele. The first preventive or management principle of breast inflammation is avoidance of excessively high intra-alveolar and intra-ductal pressures, which prevents strain and rupture of a critical mass of lactocyte tight junctions. This is achieved by frequent and flexible milk removal. The second preventive or management principle is elimination of the mechanical forces which result in high intra-alveolar pressures. This requires elimination of conflicting vectors of force upon the nipple and breast tissue during milk removal; avoidance of focussed external pressure applied to the breast, including avoidance of lump massage or vibration; and avoidance of other prolonged external pressures upon the breast. Three other key preventive or management principles are discussed. Conservative management is expected to be effective for most, once recommendations to massage or vibrate out lumps, which worsen micro-vascular trauma and inflammation, are ceased.

Re-thinking lactation-related nipple pain and damage

“…Second, the same conflicting intra-oral vectors of force, which result in nipple inflammation and pain also compress lactiferous ducts and impair milk transfer, downregulating milk production. 9,17,18,26,27 This is corroborated by the finding that infants whose mothers have nipple pain may transfer less milk (Box 2). 57,58 The lactating nipple-areolar complex is characterized by unique protective factors and unique exposure to risks relative to other human skin sites…”

“…Pump on lowest effective vacuum setting and for short periods of time, for example, 10 min, because frequent short pumping is more effective in milk removal and milk generation than less often, longer periods; 18…”

“…17 The second article builds on this mechanobiological model to re-think classification, prevention, and management of the range of breast inflammations commonly known as engorgement, blocked ducts, phlegmon, subacute mastitis, mastitis, and abscess. 18 This third article addresses the common lactationrelated problem of pain of the nipple-areolar complex, including of the nipple stroma (i.e. structural connective tissue of the mammary papilla in which vasculature, ducts, and nerve fibres are embedded).…”

“…17 The second article builds on this mechanobiological model to re-think classification, prevention, and management of the range of breast inflammations commonly known as engorgement, blocked ducts, phlegmon, subacute mastitis, mastitis, and abscess. 18…”

Re-thinking benign inflammation of the lactating breast: A mechanobiological model

“…During an episode of BLBI, total bacterial counts climb, with decreased diversity of species, and higher counts of those species identified, often including Staphylococcus . 19,36,74 Applying a complex systems lens, these perturbations characterize an ecosystem adapting under stress, acting to restore equilibrium through upregulation of some feedback loops and downregulation of others. The milk microbiome participates in the activation of myriad immune feedback loops within multiple complex systems (e.g.…”