The resorption is necessary to dispose of stalled secretions inside the duct - and at least equally important it affects osmotic balance which in turn is an important mechanism in the control of lactogenesis (this is relevant both in puerperal and nonpuerperal mastitis). While in lactating women this would appear to be a very plausible pathogenesis, there is some uncertainty about the pathogenesis in non-lactating women where breast secretions should be apriori minimal. It appears pathologic stimulation of lactogenesis must be present as well to cause subareolar abscess and treatment success with bromocriptin appears to confirm this as compared to poor success rate of the usual antibiotic and surgical treatments documented by Hanavadi et al.Further uncertainty in the relation of SMOLD and the subareolar abscess is that squamous metaplasia is very often caused by inflammatory processes. SMOLD could be the cause of the inflammation – or the result of a previous or longstanding inflammation. SMOLD usually affects multiple ducts and frequently (relative to extremely low absolute prevalence) both breasts hence it is very likely that systemic changes such as hormonal interactions are involved. At least the following factors have been considered in the aetiology of SMOLD: reactive change to chronic inflammation, systemic hormonal changes, smoking, dysregulation in beta-catenin expression, changes in retinoic acid and vitamin D metabolism or expression. Vitamin A deficiency may cause epidermilization of the ducts and squamous metaplasia and likely also contributes to infection. Vitamin A deficiency has been observed to cause squamous metaplasia in many types of epithelia.
Also called Zuskas disease (only nonpuerperal case), subareolar abscess is a subcutaneous abscess of the breast tissue beneath the areola of the nipple. It is a frequently aseptic inflammation and has been associated with squamous metaplasia of lactiferous ducts. The term is usually understood to include breast abscesses located in the retroareolar region or the periareolar region but not those located in the periphery of the breast. Subareolar abscess can develop both during lactation or extrapuerperal, the abscess is often flaring up and down with repeated fistulation. Pathophysiology
90% of cases are smokers, however only a very small fraction of smokers appear to develop this lesion. It has been speculated that either the direct toxic effect or hormonal changes related to smoking could cause squamous metaplasia of lactiferous ducts. It is not well established whether the lesion regresses after smoking cessation. Extrapuerperal cases are often associated with hyperprolactinemia or with thyroid problems. Also diabetes mellitus may be a contributing factor in nonpuerperal breast abscess. Treatment
Treatment is problematic unless an underlying endocrine disorder can be successfully diagnosed and treated. A study by Goepel and Panhke provided indications that the inflammation should be controlled by bromocriptine even in absence of hyperprolactinemia.Antibiotic treatment is given in case of acute inflammation. However, this alone is rarely effective, and the treatment of a subareaolar abscess is primarily surgical. In case of an acute abscess, incision and drainage are performed, followed by antibiotics treatment.