What is Acute Mastitis (Mastitis)?
Mastitis is when the breast becomes inflamed. There are two main types: lactational and non-lactational mastitis. Lactational mastitis is more common. Non-lactational mastitis has two further types: periductal mastitis and a rare form called idiopathic granulomatous mastitis (IGM).
Lactational mastitis, also known as puerperal mastitis, usually happens when milk ducts become overfilled for a long period. It can occur when bacteria get in through cracks in the skin. Patients might experience reddening, pain, and swelling in a specific area of the breast, along with symptoms like fever. While this can happen at any time during breastfeeding, it commonly arises within the first six weeks, with most cases decreasing after three months.
Periductal mastitis is a non-dangerous inflammation of the ducts underneath the nipple area, most commonly seen in women of childbearing age. On the other hand, IGM is a rare, non-dangerous inflammation that can seem like breast cancer. It’s typically seen in women who have given birth, usually within five years after childbirth.
What Causes Acute Mastitis (Mastitis)?
Lactational mastitis is typically caused by skin bacteria, including the very common Staphylococcus aureus. Some subtypes of this bacteria, such as methicillin-resistant S. aureus (MRSA), are becoming more frequent causes of mastitis and their risk factors should be looked into. Other bacteria like Streptococcus pyogenes, Escherichia coli, Bacteroides species, and certain non-toxic staphylococci can also cause this condition. Things that can increase the risk of getting lactational mastitis include previous bouts of mastitis, nipple cracks and tears, not enough milk flow, stress and lack of sleep in mothers, wearing bras that are too tight, and using antifungal creams on nipples.
The cause of another type of mastitis called periductal mastitis is unknown. However, smoking might contribute to its development by damaging the milk ducts and causing inflammation. In 62% to 85% of patients with this condition, bacteria are found, most commonly including S. aureus, Pseudomonas aeruginosa, and Enterococcus, Bacteroides, and Proteus species. Being overweight or having diabetes have been proposed as possible risk factors.
The cause of idiopathic granulomatous mastitis (IGM) is still unclear. Factors such as autoimmune diseases, injury, breastfeeding, using birth control pills, and overproduction of the hormone prolactin might be potential causes. An association with Corynebacterium bacterium has also been suggested, especially in patients with cystic neutrophilic granulomatous mastitis observed in their tissue samples.
Risk Factors and Frequency for Acute Mastitis (Mastitis)
Lactational mastitis is a condition that affects between 2% to 30% of breastfeeding women globally. In the United States, it occurs in about 7% to 10% of these women. Usually, the occurrence of this condition is most common during the first three weeks after giving birth.
Periductal mastitis, on the other hand, predominantly occurs in females of reproductive age and is closely associated with smoking. Globally, between 5% to 9% of women experience this condition.
- Idiopathic Granulomatous Mastitis (IGM) is a very rare condition, with its exact prevalence still uncertain.
- It usually affects women who have given birth, typically within the first five years after childbirth.
- A large number of the affected patients have a history of breastfeeding, and they usually start showing symptoms 6 months to 2 years after they stop breastfeeding.
- The average age of onset is between 32 to 34.
- Studies have shown that IGM occurs more frequently in Hispanic populations.
Signs and Symptoms of Acute Mastitis (Mastitis)
Lactational mastitis is a condition that frequently develops after breast engorgement or blocked milk ducts. It typically features symptoms like a red and painfully swollen area in one breast and a fever of 100.4 °F (38 °C) or higher. Other generalized symptoms may include chills, muscle pains, and a general feeling of weakness or discomfort.
Periductal mastitis, on the other hand, is identified by a lump near or under the areola, which could be associated with pain and skin redness. Symptoms may also include an inverted nipple, strange nipple discharge, breast abscesses, or draining fistulas.
Idiopathic granulomatous mastitis (IGM) usually shows up as a hard lump in one breast. This may also be accompanied by a drawn-in nipple, thickened skin, swollen underarm lymph nodes, ulcers, and abscesses. Due to these symptoms, it is sometimes mistaken for breast cancer in its early stages. Patients with IGM may also experience symptoms in other parts of their body, including joint pains, inflammation of the white part of the eyes (episcleritis), and skin changes.
Testing for Acute Mastitis (Mastitis)
Diagnosing lactational mastitis, an infection in a breastfeeding woman’s breast tissue, mainly relies on examining the woman’s symptoms and medical history. If your doctor suspects that there’s an abscess (or a pocket of pus), they may order a breast ultrasound. In the ultrasound image, these abscesses show up as darker patches of fluid.
When the infection is severe and doesn’t respond to the first round of antibiotics, a breast milk culture might be helpful to guide further antibiotic choice. But usually, this step is not needed. Similar is the case with blood tests. Though they can be helpful to detect a system-wide bacterial infection in a patient with severe mastitis, they’re not part of the routine testing process.
Periductal mastitis, another type of breast infection, can be diagnosed based on clinical findings. If there’s discharge from the nipple, your doctor may want to test it for bacteria. In some cases, they may suggest an ultrasound or a mammogram, especially when they’re concerned about a breast lump or cancer.
Idiopathic granulomatous mastitis (IGM), a rare inflammatory breast disease, can show similar signs to breast cancer. Therefore, it’s crucial to get a breast biopsy to make an accurate diagnosis. A biopsy involves removing a small sample of breast tissue for laboratory testing. This can be done through a core needle biopsy or excisional biopsy. In certain scenarios, checking the level of the hormone prolactin in the blood might also be useful. However, do note that ultrasound and mammogram alone are not sufficient to differentiate IGM from breast cancer.
Treatment Options for Acute Mastitis (Mastitis)
The first approach to managing breast inflammation during breastfeeding, known as lactational mastitis, is usually symptomatic treatment. In other words, it involves treating the symptoms rather than the cause of the inflammation. Regularly and fully emptying the breasts, either through breastfeeding, pumping, or hand expressing, has been found to decrease the duration of symptoms, regardless of whether antibiotics are used or not. If the breast milk is not regularly drained, it can become stagnant, leading to the infection worsening. Over-the-counter anti-inflammatory medicines can be used for pain control. Applying heat to the breast before expressing milk can help stimulate milk production and aid in its release. Meanwhile, applying cold packs to the breast after expressing can help reduce swelling and relieve pain.
If symptoms persist for more than 12 to 24 hours, antibiotics may be needed. The type of antibiotics prescribed should reflect the different sources of the infection, with S. aureus being the most common. In mild infections where there is no risk of MRSA infection, patients can begin treatment at home with either dicloxacillin or cefalexin medications. If the patient is allergic to penicillin, erythromycin can be used instead. If there is a risk of MRSA infection, they may be prescribed trimethoprim-sulfamethoxazole (TMP-SMX) or clindamycin. However, women breastfeeding infants under 1 month old, as well as infants who are jaundiced or premature, should avoid TMP-SMX. If hospitalization is required, the antibiotic vancomycin is usually administered while waiting for the results of culture and sensitivity tests. While there is limited research on the appropriate length of outpatient antibiotic treatment, most sources recommend a course of 10 to 14 days.
In cases where the inflammation is located around the milk ducts, a condition known as periductal mastitis, the default treatment is usually amoxicillin-clavulanate. Other options include dicloxacillin with metronidazole or cephalexin with metronidazole. If an abscess, or a collection of pus, is detected, doctors generally opt for an ultrasound-guided needle aspiration, which involves removing the fluid from the abscess, supplemented with antibiotic therapy. If a patient has multiple recurring infections, it might be necessary to surgically remove the inflamed milk ducts.
Finally, treatment options for a benign form of mastitis known as IGM vary widely, and can include monitoring, steroids, immunosuppressant drugs, antibiotics, and surgery. Even though IGM typically resolves without treatment within about 5 months, a recent study showed no difference in the time it takes for symptoms to resolve regardless of whether the patient was given medication or simply monitored and given supportive care. Surgery can be considered as a treatment option, but it has been reported that the inflammation reoccurs in 10% of cases, even after surgical treatment. If IGM is complicated by a secondary infection, antibiotics should be chosen based on the results of culture and sensitivity tests.
What else can Acute Mastitis (Mastitis) be?
When discussing mastitis, a condition that causes inflammation in the breast tissue, it’s important to know that there are three different types: lactational mastitis, periductal mastitis, and idiopathic granulomatous mastitis. Each of these has its own potential diagnoses to be considered:
When identifying lactational mastitis, which frequently occurs in nursing mothers, doctors may also consider these conditions:
- Overfilled, or engorged, breasts
- A blocked milk duct
- An abscess (a pocket of pus) in the breast
- Galactocele, a kind of milk-filled cyst
- Inflammatory breast cancer
For periductal mastitis, which typically happens to smokers, the following conditions may be considered:
- Duct ectasia, a condition in which the milk ducts in the breast thicken and clog
- Breast abscess
- Breast cancer
Lastly, for idiopathic granulomatous mastitis, a rare type, doctors may also consider:
- Breast cancer
- Wegener’s granulomatosis, a blood vessel disorder
- Tuberculosis, an infection that primarily affects the lungs
- Sarcoidosis, a disease with unidentified cause that leads to inflammation
- Breast abscess
What to expect with Acute Mastitis (Mastitis)
Most people who have mastitis, which is a breast infection, will get better if they get the right treatment. However, the chances of getting it again varies depending on the type.
For those who have mastitis related to breastfeeding (lactational mastitis), the chances of getting it again are between 8% and 30%.
For mastitis related to duct inflammation (periductal mastitis), the recurrence rate is between 4% and 28%.
And for a less common type of mastitis with no known cause (idiopathic granulomatous mastitis or IGM), the recurrence rate is higher, ranging from 20% to 78%.
One study found that 38% of people with IGM ended up with significant scarring, and 29% reported long-term pain.
Possible Complications When Diagnosed with Acute Mastitis (Mastitis)
One of the main complications related to breastfeeding is a condition called lactational mastitis. This is a common reason many mothers stop breastfeeding earlier than they planned. The infection in the breast and the pain associated with it are usually the main factors leading to early breastfeeding cessation. If lactational mastitis isn’t treated promptly, it could lead to the development of a breast abscess. This happens to around 3% to 11% of patients.
Other types of mastitis, like periductal mastitis and IGM, can also lead to complications such as the formation of abscesses or fistulas. These non-lactational forms of mastitis frequently reoccur and may result in scarring and deformation of the breast tissue.
Issues related to breastfeeding include:
- Lactational mastitis that can lead to early breastfeeding termination
- Infection and pain associated with mastitis
- Breast abscess, which can develop in 3% to 11% of untreated lactational mastitis patients
- Periductal mastitis and IGM, other forms of mastitis associated with recurrence
- Formation of abscess or fistula
- Scarring and deformation of the breast tissue due to non-lactational mastitis
Preventing Acute Mastitis (Mastitis)
Lactational mastitis, or breast inflammation, often develops after a period when the milk is not fully drained from the breast. So, it’s important to teach patients how to prevent this from happening. This can include discussion on the right frequency of feeding and how to get their baby to latch on properly. Sore nipples are common when women are breastfeeding and if this happens a lot, they may breastfeed less often. This makes the milk build up, which can increase the risk of mastitis. So, it’s very important to show patients how to manage or reduce their pain.
If a patient has lactational mastitis, they might want to stop breastfeeding because of the pain and worry about passing on the infection to their baby. However, doctors need to reassure patients that it is safe to breastfeed when they have mastitis and encourage them to continue if they want to. If a patient doesn’t want to carry on breastfeeding, it’s important to tell them they still need to empty their breasts, and to show them other ways of doing this, like using a breast pump or expressing milk by hand.
Furthermore, it’s not just patients who need to be educated, doctors and healthcare professionals also need to know the right advice to give. Some doctors are incorrectly telling patients with mastitis to stop breastfeeding. This not only makes it more likely for an abscess to develop, but it can also mean they stop breastfeeding earlier than planned, meaning both the mother and baby miss out on the benefits.
Lastly, the condition of periductal mastitis is almost only found in smokers. Encouraging smokers to quit can help lessen the chances of inflammation happening again.
