Mastitis causes

Nonpuerperal mastitis: Aetiology and Pathogenesis
Most clinically significant cases present as inflammation of the ductal and lobular system (galactophoritis) and possibly the immediately surrounding tissue.

Secretory stasis is the cause of nonpuerperal mastitis in about 80% of cases (Lanyi 2003). The retained secretions can get infected or cause inflammation by causing mechanical damage or leaking the lactiferous ducts. Autoimmune reaction to the secretions may be also a factor.

Several mechanisms are discussed throughout literature that may cause or predispose this (Lanyi 2003, Peters & Schuth 1989, Goepel & Pahnke 1991, Krause et al 1994).


 * secretory disease or galactorrhea
 * changes in permeability of lactiferous ducts (retention syndrome)
 * blockage of lactiferous ducts, for example duct plugging caused by squamous metaplasia of lactiferous ducts
 * trauma, injury
 * mechanical irritation caused by retention syndrome or Fibercystic Condition
 * infection
 * autoimmune reaction to luminal fluid

About 25% of patients may be hyperprolactinemic and significant coincidence with Fibercystic Condition and thyroid anomalies has been documented (Peters & Schuth 1989, Goepel & Pahnke 1991). Up to 50% of patientes experience transient hyperprolactinemia possibly caused by the inflammation or treatment and most had abnormally high Prolactin reserve (Goepel & Pahnke 1991).

Prolactin, IGF-1 and TSH are important sytemic factors in galactopoesis, their significance in secretory disease is not documented but it has been asserted that the mechanisms of secretory disease and galactopiesis are closely related (Lanyi 2003).

Permeability the of the alveolar and ductal epithelia is mostly controlled by tight junction regulation and is closely linked to galactopoiesis and possibly secretory disease. The tight junctions are regulated by a multitude of systemic (prolactin, progesterone, glucocorticoids) and local (intramammary pressure, TGF-beta, osmotic balance) factors (Nguyen & Neville 1998)

Tobacco smoking appears to be an important factor in the aetiology of squamous metaplasia of lactiferous ducts, around 90% of patients with this condition are smokers. Current smokers have the worst prognosis and highest rate of recurrent abscesses.

Acromegaly may present with symptoms of nonpuerperal mastitis.

Diabetes and many conditions with suppressed immune system can cause various infections of the breast and mastitis. Such conditions often present with inflammation of peripheral tissue and exotic infections.

Nipple piercings pose a risk due to bacterial infection following the injury and hormonal stimulation by the piercing (Jacobs et al 2003, Modest & Fangman 2002, Demirtas et al 2003).