Mastitis

Disease Description (Causes and Symptoms)

• Definition and pathophysiology: Mastitis (mastitis) is a bacterial inflammation of breast tissue. It mainly occurs when pathogens enter the milk ducts through microscopic damage on the nipple surface and multiply as milk (breast milk) becomes stagnant in the ducts. Forms include acute suppurative mastitis, chronic non-lactational mastitis, and chronic lactational mastitis (becoming chronic after an acute episode). The acute form is mainly caused by Staphylococcus aureus or streptococci; rarely, infection with beta-hemolytic streptococci may cause bilateral disease.
• Main symptoms: Fever (sometimes 38.5℃ or higher), chills, generalized weakness, localized breast pain and tenderness, localized redness, warmth, and swelling of one breast, wedge-shaped erythema, formation of a nodule (lump), and enlarged axillary lymph nodes.
• Timing and epidemiology: Common in breastfeeding women (according to the provided data, approximately 30% of breastfeeding women have been reported to experience it), with the incidence particularly high within 3 months after childbirth.

Treatment Methods

• General principles
  • Early diagnosis and treatment are important. Stopping breastfeeding is not recommended (in most cases, continue breastfeeding or pumping to maintain breast drainage).
  • Adequate rest, fluid intake, pain control (antipyretic analgesics: acetaminophen or NSAIDs), local warm compresses (apply a warm compress for 15–20 minutes before breastfeeding to improve milk flow), and wearing a comfortable bra are recommended.
• Antibiotics
  • Standard treatment: Anti-staphylococcal antibiotics (e.g., dicloxacillin 250–500 mg orally 4 times/day or the flucloxacillin class). Treatment for 10–14 days is generally used, and even after symptoms improve, it is important to complete the prescribed course to prevent recurrence.
  • If streptococcal infection is suspected: Penicillin-class antibiotics may be used.
  • In areas with a high prevalence of MRSA or when MRSA is suspected: Alternatives such as clindamycin or trimethoprim-sulfamethoxazole (TMP-SMX) may be considered (consult a doctor regarding breastfeeding safety and effects on the child).
  • Selection according to the infant's age: According to the provided data, if the infant is older than 1 month, ampicillin or erythromycin may also be considered. (The doctor determines the antibiotic based on the clinical presentation, drug allergies, and local resistance patterns.)
  • In recurrent cases or when there is no improvement, culture of milk (breast milk) is recommended to identify the causative organism and perform susceptibility testing.
• Management of Breast Abscess
  • If suspected, confirm with ultrasound. If an abscess is confirmed, repeated ultrasound-guided needle aspiration or incision and drainage may be necessary.
  • Even after drainage, continue breastfeeding or milk expression (pumping) as much as possible to prevent duct obstruction (after incision and drainage, follow wound-care instructions and the medical team's guidance).
• Surgery
  • Surgical removal may be necessary in cases of chronic nodular lesions or tissue necrosis (particularly in chronic lactational lesions).
• Additional tests and differential diagnosis
  • Breast ultrasound and mammography (when necessary); biopsy if there are recurrent localized or atypical findings (to rule out inflammatory breast cancer).

Outpatient Visit Checklist (Including Example Questions)

• Items and records to prepare
  • List of current medications (antibiotics, pain relievers, vitamins, etc.) and any drug allergies
  • When symptoms began, whether there has been a fever, and the highest recorded temperature
  • Photos of breast redness or a lump (size and location), if possible
  • Breastfeeding frequency and method (direct breastfeeding/storage and pumping), and the baby's age
  • History of previous mastitis or breast abscess, and any recent breast procedures or trauma
  • Recent test results (breast imaging, blood tests, etc.) or notes on the doctor's findings
• Information about tests that may be performed during an outpatient visit
  • Breast ultrasound and, in some cases, mammography (especially when a non-lactational breast lesion is suspected)
  • Milk culture and blood tests (inflammatory markers), if necessary
• Example questions that are useful to ask during an outpatient visit (for patients)
  • "Which antibiotic is recommended for my current symptoms, and how long should I take it?"
  • "Is it okay to continue breastfeeding? What is the best way to feed the baby?"

General Example Questions to Ask the Doctor

• What are the side effects of this medication (the prescribed antibiotic), and is it safe while breastfeeding?
• If my symptoms do not improve, by when do I need a follow-up visit or additional tests?
• How can we determine whether the condition has progressed to a breast abscess? If drainage (aspiration) is needed, when should it be performed?
• What lifestyle and breastfeeding practices can help reduce recurrence?
• I am concerned about the possibility of chronic disease or changes in the shape of my breast (such as nipple inversion). What is the prognosis?

Examples of Condition-Specific Questions

• Breastfeeding-related
  • "What specific methods (positioning, pressure, or pump use) do you recommend to safely continue breastfeeding while treating the blocked area (such as cracked nipples)?"
• Abscess-related
  • "An abscess is suspected on ultrasound. Would nonsurgical drainage (needle aspiration) be sufficient as the first treatment, or is incision and drainage likely to be necessary?"

(If necessary, write down the questions above and show them to the doctor during the visit to make the consultation easier.)

Additional note: If symptoms are severe (high fever or worsening systemic symptoms), do not improve within 24–48 hours, or there are signs suggestive of an abscess, visit a medical institution promptly for specialized treatment such as imaging tests, drainage, or adjustment of antibiotics.