What is the appropriate treatment for mastitis in a 70-year-old woman?

Treatment of Mastitis in a 70-Year-Old Woman

In a 70-year-old woman with mastitis, you must first rule out inflammatory breast cancer with urgent mammography and ultrasound, then treat with antibiotics targeting Staphylococcus aureus (dicloxacillin or cloxacillin as first-line) while draining any fluid collections via ultrasound-guided needle aspiration or incision and drainage for larger abscesses.

Critical First Step: Rule Out Malignancy

At age 70, mastitis is non-lactational and inflammatory breast cancer must be excluded immediately before initiating treatment. The 2025 American Society of Breast Surgeons guidelines emphasize distinguishing infectious from inflammatory conditions 1. Obtain:

• Mammography with digital breast tomosynthesis (DBT) - appropriate for women ≥40 years with focal breast symptoms 2
• Ultrasound - complementary to mammography to identify fluid collections and assess for underlying masses 2
• Core needle biopsy if imaging shows suspicious features or if the clinical presentation is atypical

Determine the Type of Non-Lactational Mastitis

Once malignancy is excluded, identify the specific etiology:

Bacterial Mastitis (Most Common)

• Clinical features: Erythema, warmth, swelling, pain, fever
• Causative organisms: Staphylococcus aureus (41%), coagulase-negative staphylococci (41%), anaerobes (11%) 3
• Obtain milk/fluid culture to identify organism and antibiotic sensitivities 4

Periductal Mastitis with SMOLD

• Recurrent periareolar abscesses
• May present with nipple discharge or fistula formation
• Requires different management approach 1

Granulomatous Mastitis

• Requires core biopsy confirmation with characteristic histology 1, 5
• Presents as painful mass with gradual enlargement
• Distinct from bacterial mastitis

Treatment Algorithm for Bacterial Mastitis

Antibiotic Therapy

First-line: Dicloxacillin or cloxacillin for at least 10 days if phlegmon is present 4, 1

• These cover beta-lactamase-producing Staphylococcus aureus, the most common pathogen
• Adjust based on culture results when available

Management of Fluid Collections

Collections <5 cm without loculations:

• Ultrasound-guided needle aspiration (US-NA) achieves 85-92% resolution rates with shorter healing times 6

Collections >5 cm, multiloculated, or recurrent:

• Stab incision with drain placement (no packing) under local anesthesia 1
• Operative drainage only if office procedure not tolerated
• Avoid repeated aspirations which can prolong healing

Special Considerations for Granulomatous Mastitis

If core biopsy confirms granulomatous mastitis:

Cystic Neutrophilic Granulomatous Mastitis (CNGM)

• Associated with Corynebacterium infection
• Empiric treatment: Doxycycline 1

Idiopathic Granulomatous Mastitis

• No role for empiric antibiotics if no bacteria identified 1, 5
• First-line: Repeated intralesional steroid injections for worsening symptoms 1, 5
• Avoid surgical excision - reserve for complicated/refractory cases
• Cases can take up to 18 months to resolve and often recur 1
• Refractory cases may require oral steroids or biologics (methotrexate, azathioprine) 1, 5

Management of Periductal Mastitis with SMOLD

• Antibiotics plus aspiration for fluid collections 1
• Operative excision required if fistula present or recurrent episodes
• Use radial incision to remove diseased ducts within and below nipple 1

Common Pitfalls to Avoid

1. Failing to rule out inflammatory breast cancer in elderly women - this is the most critical error
2. Packing abscess cavities after drainage - use drain placement without packing 1
3. Repeated aspirations for granulomatous mastitis - use intralesional steroids instead 1
4. Using beta-lactamase-sensitive antibiotics - most S. aureus strains are resistant 4
5. Surgical excision as first-line for granulomatous mastitis - this worsens outcomes 1
6. Stopping antibiotics before 10 days when phlegmon present 1