Last reviewed: 12 Apr 2021
Last updated: 18 Feb 2020



History and exam

Key diagnostic factors

  • fever
  • decreased milk outflow
  • breast warmth
  • breast tenderness
  • breast firmness
  • breast swelling
  • breast erythema
  • flu-like symptoms, malaise, and myalgia
  • breast pain
  • breast mass
  • fistula

Other diagnostic factors

  • nipple discharge
  • nipple inversion/retraction
  • lymphadenopathy
  • extra-mammary skin lesions

Risk factors

  • female sex
  • women aged >30 years
  • poor breast-feeding technique
  • lactation
  • 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
  • immunosuppression
  • hospital admission
  • breast trauma
  • primiparity
  • 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

Diagnostic investigations

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
  • mammogram
  • milk for leukocyte counts and bacteria quantification
  • culture from swab/aspirate from infant's and mother's oral cavity and nasopharynx
  • CBC
  • tuberculin skin test (purified protein derivative)

Treatment algorithm


Holly S. Mason

Assistant Professor of Surgery

University of Massachusetts Medical School - Baystate




HSM is a board member of the American Society of Breast Surgeons Foundation.

Dr Holly S. Mason would like to gratefully acknowledge Dr Jose A. Martagon-Villamil, Dr Daniel Skiest, Dr Gina Berthold, and Dr Liron Pantanowitz, previous contributors to this topic.


JAMV, DS, and GB declare that they have no competing interests. LP is a co-author of references cited in this topic.

Peer reviewersVIEW ALL

Program Officer

National Institutes of Health

National Cancer Institute




ES declares that he has no competing interests.

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.

The G. Rainey Williams Professor of Surgical Oncology

University of Oklahoma

Oklahoma City



WD declares that he has no competing interests.

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