Мастит: причины, симптомы и лечение при грудном вскармливании и вне его.

When it occurs in breastfeeding mothers, it is known as puerperal mastitis, lactation mastitis, or lactational mastitis. When it occurs in non breastfeeding women it is known as non puerperal or non lactational mastitis. Mastitis can, in rare cases, occur in men. Inflammatory breast cancer has symptoms very similar to mastitis and must be ruled out. The symptoms are similar for puerperal and nonpuerperal mastitis but predisposing factors and treatment can be very different.

Puerperal mastitis is the inflammation of the breast in connection with pregnancy, breastfeeding or weaning. Since one of the most prominent symptoms is tension and engorgement of the breast, it is thought to be caused by blocked milk ducts or milk excess. It is relatively common; estimates range depending on methodology between 5–33%. However, only about 0.4–0.5% of breastfeeding mothers develop an abscess.

A breast abscess is a collection of pus that develops in the breast with various causes. During lactation, breast abscess develops only rarely, most sources cite about 0.4–0.5% of breastfeeding women. Known risk factors are age over 30, primiparous and late delivery. No correlation was found with smoking status; however, this may be in part because far fewer smoking women choose to breastfeed. Antibiotics were not shown effective in prevention of lactation abscess but are useful to treat a secondary infection (see the section on the treatment of breast abscess in this article). Keratinizing squamous metaplasia of lactiferous ducts may play a similar role in the pathogenesis of nonpuerperal subareolar abscess.

Since the 1980s mastitis has often been divided into non infectious and infectious sub groups. However, recent research suggests that it may not be feasible to make divisions in this way. It has been shown that types and amounts of potentially pathogenic bacteria in breast milk are not correlated to the severity of symptoms. Moreover, although only 15% of women with mastitis in Kvist et al. 's study were given antibiotics, all recovered and few had recurring symptoms. Many healthy breastfeeding women wishing to donate breast milk have potentially pathogenic bacteria in their milk but have no symptoms of mastitis.

Mastitis typically develops when the milk is not properly removed from the breast. Milk stasis can lead to the milk ducts in the breasts becoming blocked, as the breast milk is not being properly and regularly expressed. It has also been suggested that blocked milk ducts can occur as a result of pressure on the breast, such as tight fitting clothing or an over restrictive bra, although there is sparse evidence for this supposition. Mastitis may occur when the baby is not appropriately attached to the breast while feeding, when the baby has infrequent feeds or has problems suckling the milk out of the breast. 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. There is a possibility that infants carrying infectious pathogens in their noses can infect their mothers; the clinical significance of this finding is still unknown. Mastitis can also develop due to contamination of a breast implant or any other foreign body, for example after nipple piercing. In such cases, the removal of the foreign body is indicated. Women who are breastfeeding are at risk for developing mastitis especially if they have sore or cracked nipples or have had mastitis before while breastfeeding another baby. Also, the chances of getting mastitis increases if women use only one position to breastfeed or wear a tight fitting bra, which may restrict milk flow Difficulties in getting a nursing infant to latch on to the breast can also increase the risk for mastitis. Women with diabetes, chronic illness, AIDS, or an impaired immune system may be more susceptible to the development of mastitis. Infection is usually caused by Staphylococcus aureus. Infectious pathogens commonly associated with mastitis are Staphylococcus aureus, Streptococcus spp. and Gram negative bacilli such as Escherichia coli. Salmonella spp., mycobacteria, and fungi such as Candida and Cryptococcus have been identified in rare instances. and over all there is insufficient evidence to confirm or refute the effectiveness of antibiotic therapy for treating lactational mastitis.

The diagnosis of mastitis and breast abscess can usually be made based on a physical examination. However diagnosis during lactation is particularly problematic, often leading to delayed diagnosis and treatment. Some data suggest that noninflammatory breast cancer incidence is increased within a year following episodes of nonpuerperal mastitis and special care is required for follow up cancer prevention screening. So far only data from short term observation is available and total risk increase can not be judged. Because of the very short time between presentation of mastitis and breast cancer in this study it is considered very unlikely that the inflammation had any substantial role in carcinogenesis, rather it would appear that some precancerous lesions may increase the risk of inflammation (hyperplasia causing duct obstruction, hypersensitivity to cytokines or hormones) or the lesions may have common predisposing factors. A very serious type of breast cancer called inflammatory breast cancer presents with similar symptoms as mastitis (both puerperal and nonpuerperal). It is the most aggressive type of breast cancer with the highest mortality rate. The inflammatory phenotype of IBC is thought to be mostly caused by invasion and blocking of dermal lymphatics, however it was recently shown that NF κB target genes activation may significantly contribute to the inflammatory phenotype. Case reports show that inflammatory breast cancer symptoms can flare up following injury or inflammation making it even more likely to be mistaken for mastitis. Symptoms are also known to partially respond to progesterone and antibiotics, reaction to other common medications can not be ruled out at this point.

When mastitis is associated with breastfeeding, the treatment has to balance short term reduction of symptoms with solving the underlying problems that caused mastitis. For example, the Academy of Breastfeeding Medicine recommends against trying to "empty" the breasts, whether through pushing the baby to feed more or through using a breast pump.

For breastfeeding women with breast engorgement or light mastitis, using a warm compress may be comfortable.

In lactational mastitis, antibiotics are not needed in the overwhelming majority of cases and should be used only for bacterial infections. For people with severe infections, vancomycin is recommended. The length of antibiotic treatment ranges anywhere from 5–14 days. The effects of antibiotics has not been well studied as of 2013. A lactational phlegmon (area of inflammation) should be monitored for possible development into an abscess (walled off area filled with pus from an infection). For small breast abscesses, ultrasound guided fine needle aspiration such as to completely drain the abscess is widely recognized as a preferred initial management. One recommended treatment includes antibiotics, ultrasound evaluation and, if fluid is present, ultrasound guided fine needle aspiration of the abscess with an 18 gauge needle, under saline lavage until clear. The exudate is then sent for microbiological analysis for identification of the pathogen and determination of its antibiotic sensitivity profile, which may in turn give an indication for changing the antibiotics. At follow up, a mammography is performed if the condition has resolved; otherwise the ultrasound guided fine needle aspiration with lavage and microbiological analysis is repeated. If three to five aspirations still do not resolve the condition, percutaneous drainage in combination with placement of an indwelling catheter is indicated, and only if several attempts at ultrasound guided drainage fail, surgical resection of the inflamed lactiferous ducts (preferably performed after the acute episode is over). It is noted, however, that even the excision of the affected ducts does not necessarily prevent recurrence. There is a high statistical correlation of nonpuerperal breast abscess with diabetes mellitus (DM). On this basis, it has recently been suggested that diabetes screening should be performed on patients with such abscess. Although there are a number of recommendations regarding the treatment of breast abscesses, a 2015 review found insufficient evidence of whether needle aspiration is comparable to incision and drainage, or whether antibiotics should generally be given to women undergoing incision and drainage.

Most efforts to prevent mastitis in breastfeeding women are believed to be ineffective or have a relatively small effect. Acupoint massage probably reduces the risk somewhat.

Mastitis is quite common among breastfeeding women. The WHO estimates that although incidences vary between 2.6% and 33%, the prevalence globally is approximately 10% of breastfeeding women. Most mothers who develop mastitis usually do so within the first few weeks after delivery. Most breast infections occur within the first or second month after delivery or at the time of weaning. However, in rare cases it affects women who are not breastfeeding.