Mastitis

Mastitis is the inflammation of the mammalian mammary gland (breast in primates, udder in other mammals). It is called puerperal mastitis when it occurs in lactating mothers and non-puerperal otherwise. Mastitis can rarely occur in men. Inflammatory breast cancer has symptoms very similar to mastitis and must be ruled out.

Popular usage of the term mastitis varies by geographic region. Outside the US it is commonly used for puerperal and nonpuerperal cases, in the US the term nonpuerperal mastitis is rarely used.

Chronic cystic mastitis, also called fibrocystic disease, a condition rather than a disease, is characterized by noncancerous lumps in the breast.

American slang: here mastitis usually refers to puerperal (occurring to breastfeeding mothers) mastitis with symptoms of systemic infection. Lighter cases of puerperal mastitis are often called breast engorgement.

Names for non-puerperal mastitis are not used very consistently and include Mastitis, Subareolar Abscess, Duct Ectasia, Periductal Inflammation, Zuska's Disease and others.

In this wikipedia article mastitis is used in the original sense of the definition as inflammation of the breast with additional qualifiers where appropriate.

Mastitis is also a very common condition in Veterinary medicine.

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Puerperal mastitis

Caused by the blocking of the milk ducts while the mother is lactating (see breastfeeding). It can cause painful areas on the breasts or nipples and may lead to a fever or flu-like symptoms. Mastitis can be discerned from simple blockages by the intensity of pain, heat emanating from the area, redness and fever in the mother. In some cases the fever can become severe, requiring antibiotics; ten percent of cases develop into abscesses that need to be drained surgically.

Treatment

Massage and the application of heat can help prior to feeding as this will aid the opening of the ducts and passageways. A cold compress may be used to ease the pain when not wanting to lose the milk, though it is most appropriate to reduce the levels of milk contained. For this reason it is also advised that the baby should frequently feed from the inflamed breast. However, the content of the milk may be slightly altered, sometimes being more salty, and the taste may make the baby reject the breast at the first instance.

The presence of cracks or sores on the nipples increases the likelihood of infection. Tight clothing or ill-fitting bras may also cause problems as they compress the breasts. The most common infecting organism is Staph. aureus, and babies carrying the organism in their noses are more likely to give it to their mothers;^[1] the clinical significance of this finding is still unknown, but theoretically, removing carriage from the nursing infant's nose may help prevent recurrence.

In severe cases it may be required to stop lactation and use lactation inhibiting medication.

Prevention

A study of women attending two lactation/breastfeeding conferences concluded that management and control of stress and fatigue is important in preventing mastitis. ^[2]

Nonpuerperal mastitis

The term Nonpuerperal mastitis describes all inflammatory lesions of the breast except inflammatory breast cancer and skin related conditions like dermatitis and foliculitis. This article includes description of mastitis as well as various kinds of mammary abscesses.

Most patients are women of reproductive age but mastitis beyond the age of 60 is not uncommon. Rarely occurs in newborn children (Mastitis neonatorum) or prepubertal children.

So called pre-pubertal mastitis can occur shortly before or during the first stages of puberty of both boys and girls with very mild symptoms and resolves without intervention.

Symptoms of nonpuerperal mastitis

• in most cases local to a part of breast, often close to the nipple and areola, more often the upper inner side of the breast. Rarely whole breast affected, mostly only one breast.
• redness of the area
• pain local to affected area
• diffuse density/palpable mass of varying volume
• local overwarming, hotspots (thermographically detectable)
• swollen lymph nodes on the affected side, rarely both sides
• inflammation intensity can be repeatedly flaring up and down
• abscess

Systemic (flu like) symptoms like in puerperal mastitis are rare.

Special forms of mastitis like subareolar abscess can show rare symptoms like nipple retraction and skin dimpling.

Mammography and symptoms alone never allow reliable exclusion of breast cancer. Mastitis may also mimic several typical signs of malignancy on mammography.

Terminology

Depending on appearance, symptoms, aetiological assumptions and histopathological findings a variety of terms has been used to describe mastitis and various related aspects.

• galactopoiesis: milk production

• secretory disease: aberrant secretory activity in the lobular and lactiferous duct system, believed to be the most frequent factor causing galactophoritis. The secretions may be milk like or apocrine luminal fluid.

• retention syndrome (aka retention mastitis): accumulation of secretions in the ducts with mainly intraductal inflammation.

• galactostasis: like retention syndrome where the secret is known to be milk.

• galactophoritis: inflammation of the lobular and lactiferous duct system, mainly resulting from secretory disease and retention syndrome.

• plasma cell mastitis: plasma cells from the intraductal inflammation infiltrate surrounding tissue.

• duct ectasia: literally widening of lactiferous ducts - relatively common finding in breast exams, increase with age. Strongly correlated with cyclic and very strongly with noncyclic breast pain. Correlation with mastitis is of anecdotal quality and has been questioned by recent research.

• duct ectasia syndrome: in older literature this was used as synonym for nonpuerperal mastitis with recurring breast abscess, nipple discharge and possibly associated fibrocystic condition with blue dome cysts. Recent research shows that duct ectasia is only very weakly correlated with mastitis symptomes (inflammation, breast abscess). The use of the terms Duct Ectasia and Duct Ectasia Syndrome is inconsistent throughout the literature.

• squamous metaplasia of lactiferous ducts: cuboid cells in the epithelial lining of the lactiferous ducts transform (squamous metaplasia) to squamous epithelial cells. Present in many cases of subareolar abscesses.

• subareolar abscess: abscess bellow or in close vicinity of the areola. Mostly resulting from galactophoritis.

• retroareolar abscess: deeper (closer to chest) than the lobular ductal system and thus deeper than a subareolar abscess.

• periductal inflammation (aka periductal mastitis): inflammation infiltrated tissue surrounding lactiferous ducts. Almost synonym for subaerolar abscess. May be just a different name for plasma cell mastitis.

• fistula: fine channel draining an abscess cavity

• Zuska's disease: periareolar abscess associated with squamous metaplasia of lactiferous ducts. Some authors also associate this with nipple discharge.

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).

Treatment

Treatment according to presumed cause, diagnosis and treatment of underlying condition is very important.

Prolactin inhibiting medication has been shown to be most effective and reduce risk of recurrence (Goepel & Pahnke 1991, Krause et al 1994, Stauber & Weyerstrahl 2005, Petersen 2003, Goerke et al 2003).

Antibiotics should be given in addition to prolactin inhibiting medication if there are clear signs of infection.

Granulomatous mastitis has been treated with some success by a combination of steroids and Prolactin inhibiting medication (Krause et al 1994).

More exotic treatments for nonpuerperal mastitis that have been mentioned to show at least some efficiacy include local and systemic Progestins or Progesteron (Goepel & Pahnke 1991), antidiuretics, Vitex Agnus Castus extract and Danazol.

NSAIDs are being used to treat symptoms of the inflammation, however it must be considered that these medicaments also affect pituitary function and tend to increase Prolactin and IGF-1 levels (Caviezel et al 1983).

Many variants of surgical procedures such as duct resection have been tried to reduce the risk of recurrent subareolar abscesses. So far the success rates are limited and conservative treatment seems preferable where possible (Petersen 2003, Hannavadi et al 2005).

Approximately 30% of cases develop chronic or recurring mastitis requiring long term or indefinite treatment with Prolactin inhibiting medication (Goerke et al 2003).

Breast cancer and mastitis

Lifetime risk for breast cancer is significantly reduced for women who were pregnant and breastfeeding. Mastitis episodes do not appear to influence lifetime risk of breast cancer.

Mastitis does however cause great difficulties in diagnosis of breast cancer and delayed diagnosis and treatment can result in worse outcome.

Breast cancer may coincide with mastitis or develop shortly afterwards. All suspicious symptoms that do not completely disappear within 5 weeks must be investigated.

Breast cancer incidence during lactation is assumed to be the same like in controls. Diagnosis during lactation is particularly problematic, often leading to delayed diagnosis.

Some data suggests that breast cancer incidence is increased following episodes of nonpuerperal mastitis and special care is required for followup cancer prevention screening.

A very serious type of breast cancer called inflammatory breast cancer presents with similar symptoms as mastitis. It is the most aggressive type of breast cancer with the highest mortality rate. Case reports indicate that inflammatory breast cancer symptoms can flare up following injury or inflammation making it even more likely to be mistaken for mastitis. Because inflammatory breast cancer is mostly EGF positive this may be a reaction of a preexisting asymptomatic cancer to local cytokine stimulation following the normal injury or inflammatory response.

See also

• Breast engorgement
• Breast shell
• Failure to thrive

Numbered references

1. ^ Amir LH, Garland SM, Lumley J. (2006). "A case-control study of mastitis: nasal carriage of Staphylococcus aureus". BMC Family Practice. 7: 57. doi:10.1186/1471-2296-7-57.
2. ^ Riordan, Janice M.; Francine H. Nichols (1990). "A Descriptive Study of Lactation Mastitis in Long-Term Breastfeeding Women". Journal of Human Lactation 6 (2): 53-58. DOI: 10.1177/089033449000600213. Retrieved on 2007-12-22.

References for nonpuerperal mastitis

Many of those are in German, no usable English language literature known.

• Stauber, Weyerstahl; Gynäkologie und Geburtshilfe; 2nd edition 2005; ISBN 3-13-125342-8
• Petersen; Infektionen in Gynäkologie und Geburtshilfe; 4th edition 2003; ISBN 3-13-722904-9
• Goerke, Steller, Valet; Klinikleitfaden Gynäkologie Geburtshilfe; 6th edition 2003; ISBN 3-437-22211-2
• Lanyi M; Mammography: Diagnosis and Pathological Analysis; 2003; ISBN 3-540-44113-1, ISBN 3-540-43134-9
• Goepel E, Pahnke VG; 1991 Geburtshilfe und Frauenheilkunde; Successful therapy of nonpuerperal mastitis--already routine or still a rarity?; PMID 2040409
• Krause A, Gerber B, Rhode E.; Zentralbl Gynakol. 1994;116(8):488-91.; Puerperal and non-puerperal mastitis; PMID 7941820
• Peters F, Schuth W; JAMA. 1989 Mar 17;261(11):1618-20; Hyperprolactinemia and nonpuerperal mastitis (duct ectasia).; PMID 2918655
• Nguyen DA, Neville MC.; J Mammary Gland Biol; Tight junction regulation in the mammary gland.; PMID 10819511
• Jacobs VR, Golombeck K, Jonat W, Kiechle M.; Int J Fertil Women's Med. 2003; Mastitis nonpuerperalis after nipple piercing: time to act.; PMID 14626379
• Caviezel F, Cattaneo AG, Tell A, Corino T, Mascherpa M; Int J Clin Pharmacol Ther Toxicol.; The effect of acetylsalicylic acid and diclofenac on stimulated growth hormone and prolactin secretion in humans.; PMID 6642786
• Hanavadi S, Pereira G, Mansel RE.; Breast J. 2005; How mammillary fistulas should be managed.; PMID 15982391
• Modest GA, Fangman JJ; N Engl J Med. 2002 Nov; Nipple piercing and hyperprolactinemia.
• Demirtas Y, Sariguney Y, Cukurluoglu O, Ayhan S, Celebi C; Dermatol Surg. 2004 Aug; Nipple piercing: it is wiser to avoid in patients with hyperprolactinemia.; PMID 15274719
• http://www.gyn-endo-handbuch.de/
• Mastitis Nonpuerperalis