Breast Conditions in the Breastfeeding Mother

History and Prenatal Counseling

Health care providers should be familiar with the components of a comprehensive examination of the breasts, NAC, and regional lymph node basins. A prenatal breast examination provides an opportunity to evaluate a patient for concerning lesions and begin discussions about breastfeeding. In addition to the physical exam, providers also should inquire about the patient’s previous experience with breastfeeding and any underlying medical conditions that may affect milk production, such as infertility, obesity, and diabetes (see Chapter 15 ). Surgical and procedural history should be documented ( Box 16.1 ). No history should preclude breastfeeding, but conditions should be identified prenatally, and the patient should be counseled appropriately about potential impacts on breastfeeding.

Prenatal breastfeeding counseling should include anticipatory guidance about normal physiologic breast changes during pregnancy, including growth throughout all trimesters and production of colostrum in late pregnancy. Providers also can address significant breast growth causing pain or lymphedema and recommend targeted interventions such as breast lymphatic massage. Prenatal counseling also affords the opportunity to discuss patient concerns about the potential for breastfeeding challenges resulting from individual anatomy. Providers should reassure patients that breast size is related to the amount of intervening fat in a breast, and smaller breasts do not correlate with a decreased ability to produce milk. However, patients with examination findings consistent with breast hypoplasia (detailed under “Tubular Breast Deformity”) should be prepared for potential low milk production. Women with flat or inverted nipples should be reassured that breastfeeding is often successful and that no interventions are advised.

Breast Examination

Palpation

After careful inspection, the provider should palpate the breast and regional lymph node basins with the patient in both an upright and supine position. The examiner should use the flat part of the fingers and support the breast with the contralateral hand; because of the nodularity and density of pregnant and lactating breasts, using the fingertips or pinching between two fingers for the examination can produce false-positive findings ( Fig. 16.1 ). The upright position is best for assessing upper-outer-quadrant lesions, and the supine position reveals inframammary-fold lesions and other inferior lesions. The entire breast should be scanned with the flat of the provider’s hand in either spiral, radial, concentric circle, or vertical patterns ( Fig. 16.2 ). Palpation of the whole breast should be performed in an overlapping pattern with varying degrees of lighter and deeper pressure applied to survey the entire extent of the parenchyma. The examination should be extended superiorly to the clavicle, inferiorly to the lower rib cage, medially to the sternal border, and lateral to the midaxillary line. Masses, focal pain, and nipple discharge should be assessed.

The bilateral cervical, supraclavicular, and axillary nodes should be palpated. Enlarged axillary lymph nodes often are encountered in breastfeeding, but they should be mobile, soft, and generally <1 cm in size. They may be slightly tender, which is normal in pregnancy and lactation. Any concern for firm or immobile, matted lymph nodes should be further investigated with breast and axillary imaging, usually starting with an ultrasound.

Documentation

If the provider appreciates a concerning finding on the breast, the provider should document this by describing the size of the lesion, whether it is smooth or irregular and mobile or immobile, its location on the breast clockface, and the distance from the nipple. An examination of this documentation would include the following: “1.5 cm×2.0 cm smooth, rubbery, mobile mass at 12:00, 3 cm from the nipple” ( Fig. 16.3 ). Nipple discharge should be characterized by laterality, number of involved nipple orifices, discharge color, character, presence or absence of blood, and whether it is spontaneous.

Breast Imaging in Lactation

Breast imaging is an extension of the breast physical exam. Acute breastfeeding issues should resolve with proper intervention. Any persistent issue, such as an unrelieved plug, should be referred for breast imaging. Diagnostic imaging generally starts with a breast ultrasound and may or may not require a mammogram. Mammograms do not require interruption of breastfeeding and are safe; a bilateral mammogram results in 3 to 5 milligray (mGy) of radiation to the breasts, the equivalent of background radiation incurred over 2 months. ¹ If recommended, breast magnetic resonance imaging (MRI) can also be performed without interruption of breastfeeding. ² To reduce density from retained milk, mothers should express milk and drain the breasts fully before any breast-imaging examination. ³ If the radiologist recommends a breast biopsy of a concerning lesion, the mother should understand that this is safe without interruption of breastfeeding and that the incidence of milk fistula is <1.3% within 1 week of procedures. ⁴ Additionally, it should be noted that routine breast cancer screening in lactation is safe and should be considered in patients with a high-risk family history, a known gene mutation, or who otherwise meet screening guidelines because of age. ⁵

Poland Syndrome

Poland syndrome is a unilateral anomaly of the pectoralis muscle, breast, NAC, axillary fold, subcutaneous tissue, ribs, and upper limb. Phenotype varies widely, with patients experiencing a spectrum from complete absence of a chest-wall structure to a more mildly asymmetric breast compared with the contralateral side. The thorax, breast, and NAC (TBN) classification helps identify these different phenotypes and the associated degree of hypoplasia. The most common anomaly in women is T1B1N2 (hypoplasia or aplasia of the pectoralis muscle and soft tissue with no rib or sternal defect; breast hypoplasia without aplasia; and NAC hypoplasia and dislocation without the absence of the NAC; Fig. 16.4 ). ⁶ Nearly 70% of defects present as right-sided rather than left-sided. ⁶ Women with asymmetric breasts and/or chest walls should be referred for prenatal counseling and close postpartum support because they may experience challenges with milk production on the affected side. Some of these women also may have undergone previous reconstructive surgery and present with the appearance of a normally developed breast. Therefore the surgical history should always be obtained.

Tubular Breast Deformity

No single definition or terminology exists for the broad category that is variably described as insufficient glandular tissue (IGT), hypoplastic breasts, or tuberous/tubular breast deformity. Many clinicians will utilize the term IGT to describe an anatomic phenomenon that includes the following: widely spaced breasts; lack of lower quadrant fullness; a fibrous, inelastic NAC; lack of or minimal breast growth during pregnancy; and lack of or minimal engorgement postpartum. Others will utilize IGT to describe breasts that are normal in anatomic appearance but otherwise do not experience normal gestational breast growth or postpartum engorgement and ultimately produce insufficient milk for the infant. It is likely that IGT represents variable clinical scenarios in which embryologic factors result in the development of anatomically abnormal breasts that produce insufficient milk, whereas reproductive and hormonal factors may affect the glandular tissue of anatomically normal-appearing breasts and their ability to produce sufficient milk.

A true tubular or tuberous breast deformity with an anatomically abnormal external appearance has an unknown etiology, although it has been theorized to result from embryologic failure of thoracic tissue differentiation or fascial maldevelopment. Histologically, these breasts demonstrate marked fibrosis in the glandular tissue and large concentrations of collagen and elastic fibers comprising a constrictive areolar ring. ⁷ Grossly, the breast resembles a cylindrical shape with an elongated, vertical appearance. Characteristics include parenchymal hypoplasia, superior malposition of the inframammary fold with decreased volume of the inferior breast skin, and herniation of breast glandular tissue through a constricted areolar-nipple complex (ANC) ( Fig. 16.5 ). ⁸ Grolleau and colleagues developed the most widely accepted classification system, in which type I breasts are hypoplastic in the medial quadrant, type II in the bilateral inferior quadrants, and type III in all four quadrants. ⁹ As delineated by the classification system, a spectrum of disease exists, and very commonly, patients have asymmetrical breasts.

These patients exhibit variable challenges with breastfeeding. Most have reduced milk production that may improve with each subsequent pregnancy and lactation and may respond to galactagogues. ¹⁰ There is no definitive literature or management algorithm, and patients should be counseled during pregnancy and followed closely in the postpartum period. Additionally, many of these patients may have undergone plastic surgery procedures, such as augmentation mammaplasty, before pregnancy. Therefore, as described in the section on plastic surgery, providers should inquire about a patient’s reason for undergoing plastic surgery in the past.

Ectodermal Dysplasia

Ectodermal dysplasias are a group of genetic disorders characterized by abnormal embryologic events resulting in malformations of ectodermal appendages, including the sweat glands, hair, nails, and teeth. Phenotype varies considerably and may include breast and/or NAC anomalies. Some individuals have breast hypoplasia, whereas others have amastia—either unilateral or bilateral—and the NAC may be normal, abnormal, or congenitally absent. ¹¹ In a study of 38 women with ectodermal dysplasia, over half reported exceptionally flat nipples, whereas others had inverted nipples, and some had supernumerary nipples. ¹² In addition, nearly all women had a paucity or complete lack of Montgomery glands. The majority of participants reported difficulty breastfeeding, and the primary reason for the difficulty was perceived to be flat nipples. ¹² Multiple reconstructive surgery options exist for patients with ectodermal dysplasia affecting the breast. ¹¹ However, these procedures are cosmetic in nature and do not improve the underlying developmental disorder affecting the glandular tissue.

Accessory Breast Tissue

Accessory breast tissue presents most commonly in the axilla, although it has been observed in multiple locations throughout the embryologic mammary ridge. It is most common in Native American and Asian populations and has an overall prevalence of approximately 2% to 6%. ¹³ This tissue can enlarge and become more cosmetically unappealing with each subsequent pregnancy and can also cause pain and chafing with bras. It is frequently engorged postpartum. Nonsteroidal antiinflammatory drugs (NSAIDs) and ice can relieve the pain of engorgement, and the tissue should involute if not stimulated or drained. It is possible for this tissue to develop mastitis and other infectious or inflammatory complications, which should be treated per protocol. ¹⁴ Accessory breast tissue can be managed with liposuction and/or surgical resection. However, unless the tissue is causing significant psychological or physical distress, resection should be deferred until childbearing is complete.

Supernumerary Nipples

Like accessory breast tissue, supernumerary nipples can present in any location along the mammary ridge and occur in up to 6% of the population. ¹⁵ They may present with a subtle, mole-like appearance or may appear with a full NAC with a small amount of associated breast parenchyma. Polythelia describes an areola with an associated nipple; an isolated areola can present, but a nipple will never exist without an areola. They often enlarge during pregnancy and lactation and will involute if not stimulated. Removal of a small accessory NAC is a minor surgical procedure and may be reasonable to perform before childbearing.

Inverted Nipples

Nipple inversion occurs in approximately 3% to 10% of the population and likely results from congenital connective tissue tethering, failure of the lactiferous sinuses to lengthen, and failure of the complete growth of the mesenchyme. Alternatively, this condition may be acquired after surgery or the development of malignancy or breast infections. ¹⁶ Grade I inversions can be manually everted and maintain projection, grade II inversions return promptly to the inverted position, and grade III inversions are invaginated and difficult to evert. Patients should be reassured that breastfeeding can be successful with flat or inverted nipples, and there are no data to support everting or otherwise “preparing” any nipple while pregnant for breastfeeding. ¹⁷ , ¹⁸ In fact, in a small randomized trial, women allocated to breast shells prenatally were less likely to initiate breastfeeding than women in the control group and less likely to be successfully breastfeeding at 6 weeks. ¹⁷ Four of the five women allocated to breast shells who decided not to initiate breastfeeding described problems wearing the shells as the reason.

Often, tethering bands may release naturally postpartum with breastfeeding and pumping. However, patient experience is variable, and some of the more tenacious inversions may never release. A history of a surgical procedure to evert the nipple may damage ducts, create scar tissue, and affect breastfeeding. This is discussed in more detail in the plastic surgery section, and it is not recommended that patients undergo this procedure before childbearing.

Anatomy

Collecting ducts in the 2-mm size range drain each breast segment and coalesce into 5- to 8-mm subareolar lactiferous sinuses ( Fig. 16.6 ). ¹⁹ Most individuals have five to nine nipple orifices. ²⁰ The areola includes sebaceous glands, apocrine glands, and hair follicles, and its pigmentation varies widely. There is minimal subcutaneous fat separating the NAC from the underlying breast parenchyma. ¹⁶

Montgomery glands, also termed Montgomery tubercles , are modified sebaceous glands that serve to lubricate the nipple and areola and attract the infant to the breast. They enlarge during pregnancy and lactation. ²¹ Like other sebaceous glands, they can become obstructed and infected. Treatment involves a focal application of salicylic acid, warm compression, gentle expression, and drainage of any deeper abscess that has developed. If recurrently obstructed, women should avoid excessive use of nipple cream and other lubricants. They also should avoid continually stimulating and expressing the glands because this will potentiate additional drainage and/or hypertrophy and scarring. Aberrant milk drainage through a Montgomery gland is common and also should not be stimulated for similar reasons.

Morphology

Nipple morphology is widely variable with respect to diameter, protrusion, and contour ( Fig. 16.7 ). ²² In the setting of nipple inversion or very small or flat nipples, shaping the NAC to enable a deep latch and milk transfer may be advisable. This can be done by compressing the breast and areola between two fingers with either a C, V, or scissor hold. The laid-back or side-lying positions, particularly in the setting of very large breasts, also may enable a deeper infant latch. Breast shells are not advisable to attempt to evert a nipple because they may promote edema and restrict the pliability of the NAC. Ultimately, latch challenges are usually less related to the size and/or inversion of a nipple and more to the elasticity of the tissue.

Extremely large nipples may present a problem with a small infant or an infant with a small gape. Attempting to feed may result in gagging or inability to latch; in this case, a shield may taper and form the nipple into an acceptable shape and size for the infant. Manual expression and reverse-pressure softening, which soften the areola to make it more pliable before putting the infant to the breast, also may help. In situations of both large and small nipples, limited pre-breastfeeding use of an electric or manual pump may facilitate the infant’s latch-on by drawing the nipple into a teat shape. Mothers with extremely large nipples and smaller infants initially may need to pump to maintain their milk production if the baby is not able to latch deeply into the breast parenchyma to transfer milk and/or stimulate maternal production.

Nipple Care

Excessive cleansing, whether prenatally or postpartum, can remove natural oils and predispose the skin to breakdown; patients should not use any drying agents such as antiseptics, alcohol, or saline. ²³ Some women may choose to lubricate dry skin with nursing balms. Although this may not cause harm, women should be aware of potentially allergenic ingredients, such as lanolin and coconut, and tailor choice of balm accordingly ( Box 16.2 ).

In the setting of trauma, nipples should be treated with moist, closed wound healing, as detailed later in the chapter. Following known principles of wound care, the nipples should not be soaked in saline, be rubbed with washcloths, undergo rigorous cleaning regimens with alcohol and other irritating drying products, or be “dried out.” Gentian violet may produce tissue ulceration, and balms containing multiple products may result in dermatitis from allergens. Topical antifungals and other topical agents can worsen vasospasm. Breast shells designed to evert the nipple are not recommended because of the secondary edema they cause.

It should be noted that many women who exclusively pump without breastfeeding may develop a white crust on their nipples. This may be dried milk or may be related to biofilm production. Researchers have documented the variation in the milk microbiome that occurs with exclusive pumping, ²⁴ and it is possible that this crust is related to that phenomenon. Although further research is necessary in this area, patients who are asymptomatic, other than noting the appearance of this crust on the nipple, should be counseled that vigorous cleaning and/or attempts to remove this crust may produce nipple trauma and/or infection.

Nipple Shields

A nipple shield is a device made of silicone or latex that is worn over the nipple and areola while an infant is suckling. Shields differ from the shells designed to evert nipples. In addition, they should not be confused with breast-pump flanges. Nipple shields are associated with multiple complications, including mastitis, plugging, and significant reductions in milk production and transfer. ²⁵ Many mothers have difficulty weaning infants off the nipple shield once it has been used regularly. ²⁶

Given these known complications, the breastfeeding dyad should undergo a thorough evaluation before the introduction of a nipple shield. Often, nipple shields are introduced when a small infant struggles to latch to a larger, pendulous breast. This may instead simply require adjustment of a position that is more amenable to feeding with large breasts, such as the laid-back or side-lying position. Infants also may refuse to latch when the flow of milk is very high; adjusting position also can address this issue without introducing nipple shields. Although nipple shields may be overused, there appear to be instances in which they can be helpful, such as when the infant is not able to latch at all, struggles to maintain a latch, or is causing severe maternal nipple discomfort. These situations may be seen in infant prematurity, tongue restrictions, severe maternal nipple inversions, infant hypotonia, or neurologic delay.

Pain

Up to 96% of mothers report nipple pain while breastfeeding. ²⁷ Nipple pain occurs most commonly in the first week postpartum ²⁷ and generally resolves within 1 to 2 weeks after appropriate intervention. ²⁸ Nipple and breast pain are risk factors for early weaning and therefore warrant prompt attention and close follow-up. ²⁹

Persistent pain may represent a multitude of different etiologies, and treatment should be tailored to the specific diagnosis ²⁹ ( Box 16.3 ). Overall, suboptimal latch is the most common cause of nipple pain. ²⁸ Other etiologies include trauma, vasospasm, dermatitis, and subacute mastitis, which are discussed individually in this section. It should be noted that because of the complex innervation of the breast and NAC, deeper breast pain may present as NAC pain or may present with concurrent deep breast pain and NAC pain. Similarly, NAC pain resulting from conditions such as vasospasm may radiate posteriorly into the breast ( Fig. 16.8 ).

If a mother has resumed menstruation, she may notice increased sensitivity before her cycle. Mothers who become pregnant while breastfeeding also may experience new nipple and/or breast pain or increased sensitivity.

In the setting of tissue damage, principles of moist, closed wound healing should be followed, as detailed later in this chapter. In brief, the nipples should be moistened with an oil-based lubricating nipple balm and covered with a nonstick dressing, such as hydrogel pads. When selecting a nipple balm, the potential for maternal allergic reactions to components such as lanolin or coconut should be considered. For severe pain in the setting of significant trauma, clinicians may utilize limited topical steroids. However, given the potential for steroids to affect healing, this approach should be individualized and monitored carefully.

Many ineffective and harmful treatments for traumatized nipples exist, and these should be avoided. A Cochrane systematic review concluded that there is insufficient evidence to recommend the “all-purpose nipple ointment” (also known as APNO or triple-nipple cream ) or expressed breast milk for nipple pain in breastfeeding women. ²⁷ Not only are superficial fungal and bacterial infections uncommon in the setting of breastfeeding, but antifungal and antibacterial creams and ointments often contain allergens that may incite dermatitis and worsen vasospasm symptoms. Expression of breast milk followed by air-drying may cause cracking and worsen trauma. Cool, wet tea bags and warm compresses can potentiate skin breakdown. The use of ice theoretically may interfere with the let-down reflex.

When a patient is experiencing significant nipple and/or breast pain, clinicians also may recommend that a patient stop breastfeeding and pump or hand-express instead. This approach should be considered cautiously because pumping can result in additional problems, such as plugging, mastitis, reduction in milk production or stimulation of overproduction, and disinterest of the baby in returning to the breast. If absolutely necessary, hand-expression may represent the most efficacious solution to resting sore nipples.

Overall, we emphasize that the specific etiology of the patient’s symptoms should be identified through careful history and examination of the breastfeeding dyad. Once all treatable etiologies have been ruled out, persistent idiopathic pain may require continued support and reexamination of the dyad and continued attention to latch and positioning. As described in the section on mastalgia, patients may benefit from pharmacologic interventions, such as NSAIDs, propranolol, and antidepressants. ²⁹ Persistent pain should be recognized as multifactorial, requiring an integrated treatment approach that addresses not only biological but also psychosocial aspects of pain. ³⁰ Counseling, physiotherapy massage, acupuncture, and other complementary and alternative medicine practices may therefore be helpful. ³⁰

Trauma

Trauma most commonly results from improper latch, ankyloglossia, unrelieved engorgement, and improperly fitting flanges or pumping on high suction. Providers also should ascertain what interventions patients may have undertaken on their own that could potentiate trauma and/or allergy. This includes soaps, oils, ointments, lubricants, and medications that can cause ulcerations (e.g., gentian violet).

Latch or pump trauma may demonstrate characteristic patterns on the nipple. Scabbing may align with the position causing harm (e.g., horizontally across the nipple for football hold, vertical for cross-cradle or cradle). Cracks at the base of the nipple may result from sucking of the lower lip or biting. Circumferential cracks at the nipple base may occur from pumping with flanges that are either too small or too large or from correctly sized flanges in the setting of excessive suction. When deep fissures have developed, beginning to nurse on the less painful side first may permit the initial let-down to occur with less pain. Then the infant can be put carefully to the affected breast, with attention to using a position that redistributes the pressure of suckling on the nipple.

The normal human wound healing time is 8 to 10 days for reepithelization after traumatic insult. ³¹ Some patients will question how nipple trauma can heal when an infant continues to stimulate the nipple frequently. The lactating breast and NAC are highly vascular ( Fig. 16.9 ) and therefore heal well, even in the setting of continued breastfeeding. With trauma, patients should apply the principles of wound healing, which include keeping the wound lubricated with an oil-based emollient cream or ointment and keeping it closed or covered with nonstick gauze or hydrogel pads. Wounds with significant exudate and seepage may benefit from polyurethane matrix pads to provide both closed wound healing and absorptive capacity. It is recommended that patients adhere to a regimen both day and night, similar to keeping a burn wound closed at all times, to enable optimal uninterrupted moist wound healing. No drying agents or drying of the nipple should occur. Some wounds respond well to medical-grade honey, which is irradiated and therefore does not pose a risk of botulism to infants who may ingest small amounts. Open wounds should not be closed with suture or surgical glue because they are not clean and therefore at high risk for wound infection. Instead, these wounds should heal following the principles of closure by secondary intention. Additionally, suture material or surgical glue may pose harm to the breastfeeding infant.

Vasospasm

Vasospasm is a painful cutaneous vasoconstriction that presents with hardening of the nipple and color changes on a spectrum from white to blue to red. Because of the complex innervation of the breast (see Fig. 16.8 ), pain can focus in the nipple or radiate deep into the breast and may last for over 30 minutes. Pain is often the worst after the baby unlatches or the mother finishes pumping. It also may present when the mother moves from a warm environment to a cooler environment, such as leaving the shower or pool, going from indoors to outdoors in the winter, or transitioning from warm weather to air conditioning. Alternatively, vasospasm may occur with no apparent trigger.

Nipple vasospasm occurs in approximately one-fifth of breastfeeding women and may be more common in those with a history of Raynaud’s phenomenon of the fingers. ³² Secondary vasospasm may occur following trauma to the nipples. Persistent vasospasm can result in a cycle that potentiates trauma as a result of vasoconstriction and inability to heal in the setting of chronic ischemia. Maternal ingestion of vasoconstrictive products, including caffeine, may worsen vasospasm, and nicotine can also contribute to symptoms. ³³ Mammary blood vessels are exquisitely sensitive to epinephrine and norepinephrine. Although fewer data exist regarding serotonin and PGF _20C as vasoconstrictive agents, it is possible they also may play a role. ³⁴ , ³⁵ , ³⁶

Treatment of vasospasm involves resolving any underlying persistent trauma, such as improper latch and positioning. As stated earlier, women with larger breasts and/or a history of breast augmentation may benefit from laid-back or side-lying nursing positions to enable deeper latch and reduce trauma from superficial latch. Patients should keep their NACs warm at all times with pads made of wool, fleece, or other insulated fiber. For additional warmth, they may place heating pads or reusable heated products, such as microwaveable rice packs or hand warmers, on top of the pads; these products should not be applied directly to the skin because of the risk of burns. As with healing trauma, these products should be used both night and day. Some women benefit from calcium, magnesium, and fish oil supplements. ³² Women who fail to respond to conservative measures may be recommended to use calcium-channel-blocker agents, such as nifedipine, under the guidance of a medical professional. ³³

Nipple Blebs

Often described as a “white dot” or a “scab,” nipple blebs are inflammatory lesions on the surface of the nipple and can cause exquisite pain with latch. They can also cause obstruction of milk flow through the nipple orifice and may present with concurrent acute mastitis. Blebs have no association with candida. Nipple blebs may be solitary and unilateral, or they may present on multiple orifices bilaterally. They generally are 1 mm or less in diameter but at times may grow larger. If repeatedly traumatized with unroofing, they can develop associated reactive tissue and/or scarring and appear larger and more fleshy. Infants may release a superficial bleb while nursing, or more tenacious blebs may persist regardless of interventions. Blebs are often associated with hyperlactation, subacute mastitis/dysbiosis, pumping, and localized plugging. ³⁷

Despite the morbidity blebs confer to the nursing dyad, little published data exist regarding etiology, prevalence, and management. O’Hara described, in a five-patient cohort, that bleb histology showed signs of inflammation, including histiocytes with foamy cytoplasmic vacuoles and fibrin deposition. ³⁸ This led to the conclusion that mid-potency topical steroids were likely to be helpful in resolving blebs. Other providers have utilized sunflower lecithin by mouth to emulsify milk and treat underlying ductal plugging. ³⁹ If subacute mastitis/dysbiosis and/or hyperlactation is contributing to the development of multiple bilateral blebs, the treatment algorithms for those conditions should be followed. Regardless of additional treatments pursued, topical steroid cream may reduce the tenacity and pain of the bleb. In acutely obstructing situations, health care providers should unroof the bleb using a sterile 18-gauge needle, approaching the nipple parallel to the surface of the bleb. A nipple orifice should never be probed directly with a needle or other traumatic device, and patients should not be encouraged to perform this at home, because continued trauma can potentiate scarring and worsening of symptoms.

It should be noted that blebs are different from the sucking blister that appears early in lactation and results from vigorous suckling, malposition, or high pump suction. This type of blister covers a larger area, appears more vesicular with a thin membrane and underlying fluid, and is not associated with underlying ductal plugging.

Subacute Mastitis

Subacute mastitis, also known as breast dysbiosis , represents an imbalance of the breast flora akin to bacterial vaginosis. These patients may present with a history of previously treated recurrent acute mastitis. There may be superimposed hyperlactation and painful nipple blebs, and patients may be exclusively pumping. ³⁷ Patients often describe deep, burning breast pain; feelings of fullness; and painful nipples and latch. A white biofilm may be present on the surface of the nipple. This constellation of signs and symptoms is often misdiagnosed as mammary candidiasis, which is not supported by microbiologic evidence. ⁴⁰

Evaluation includes performing a sterile breast-milk culture to tailor the antibiotic choice. Although this culture may often grow a coagulase-negative Staphylococcus or Streptococcus species, it also may fail to grow any organism. ⁴⁰ A case series documented that patients can undergo empiric treatment with extended antibiotics that target chronic, intracellular infections, such as azithromycin. ⁴¹ In more mild cases, probiotics directed at the breast flora (as described in the section on acute mastitis) may resolve pain; however, no published data on this approach exist. Sunflower lecithin may be used to reduce plugging. Hyperlactation should be addressed and treated.