Breast infections (including infectious mastitis and breast abscess) more commonly affect women aged 15-45 years, especially those who are lactating. However, mastitis and breast abscess can occur at any age.
Staphylococcus aureus is the most frequent pathogen isolated.
Prompt and appropriate management of mastitis usually leads to a timely resolution and prevents complications, such as a breast abscess.
Treatment of infectious and noninfectious mastitis includes antibiotic therapy and effective milk removal if lactating.
Breast abscess requires both the removal of pus and antibiotic therapy. Interventions can include aspiration and incision and drainage procedures.
It is imperative to identify and treat any underlying coexistent causes of infection to facilitate resolution and prevent recurrence. It is also necessary to exclude breast carcinoma.
Mastitis is defined as inflammation of the breast with or without infection. Mastitis with infection may be lactational (puerperal) or nonlactational (e.g., duct ectasia). Noninfectious mastitis includes idiopathic granulomatous inflammation and other inflammatory conditions (e.g., foreign body reaction). A breast abscess is a localized area of infection with a walled-off collection of pus. It may or may not be associated with mastitis.
History and exam
Key diagnostic factors
- decreased milk outflow
- breast warmth
- breast tenderness
- breast firmness
- breast swelling
- breast erythema
- flu-like symptoms, malaise, and myalgia
- breast pain
- breast mass
Other diagnostic factors
- nipple discharge
- nipple inversion/retraction
- extra-mammary skin lesions
- female sex
- women aged >30 years
- poor breast-feeding technique
- milk stasis
- nipple injury
- previous mastitis
- prolonged mastitis (breast abscess)
- prior breast abscess (breast abscess)
- shaving or plucking areola hair
- anatomical breast defect, mammoplasty, or scar
- other underlying breast condition
- nipple piercing
- foreign body
- skin infection
- Staphylococcus aureus carrier
- hospital admission
- breast trauma
- overabundant milk supply
- postmaturity (breast abscess)
- complications of delivery
- maternal fatigue
- tight clothing
- antifungal nipple cream
- fibrocystic breast disease
- cigarette smoking
- vaginal manipulation (breast abscess)
- poor nutrition
- antiretroviral therapy
1st investigations to order
- breast ultrasound
- diagnostic needle aspiration drainage
- cytology of nipple discharge or sample from fine-needle aspiration
- milk, aspirate, discharge, or biopsy tissue for culture and sensitivity
- histopathologic examination of biopsy tissue
Investigations to consider
- pregnancy test
- blood culture and sensitivity
- milk for leukocyte counts and bacteria quantification
- tuberculin skin test (purified protein derivative)
breast abscess post acute intervention
recurrence of mastitis and/or breast abscess
Jesse Casaubon, DO, FSSO
Breast Surgical Oncologist
JC declares that he has no competing interests.
Dr Jesse Casaubon would like to gratefully acknowledge Dr Holly S. Mason, Dr Jose A. Martagon-Villamil, Dr Daniel Skiest, Dr Gina Berthold, and Dr Liron Pantanowitz, previous contributors to this topic.
HSM, JAMV, DS, and GB declare that they have no competing interests. LP is a co-author of references cited in this topic.
Edward Sauter, MD, PhD
National Institutes of Health
National Cancer Institute
ES declares that he has no competing interests.
Justin Stebbing, MA, MRCP, MRCPath, PhD
Consultant Medical Oncologist/Senior Lecturer
Department of Medical Oncology
Imperial College/Imperial Healthcare NHS Trust
Charing Cross Hospital
JS declares that he has no competing interests.
William C. Dooley, MD
The G. Rainey Williams Professor of Surgical Oncology
University of Oklahoma
WD declares that he has no competing interests.
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