A breast rash describes redness and irritation of the skin on your breast. A breast rash can also be itchy, scaly, painful or blistered.

Other terms used to describe a breast rash include dermatitis and hives.

Most breast rashes have the same causes as rashes occurring elsewhere on the body. Some rashes occur only on the breast.
Causes of rash that occur only on the breast may include:
Breast abscess
Inflammatory breast cancer
— an infection in breast tissue that most commonly affects women who are breast-feeding
Nipple dermatitis
Paget's disease of the breast

General causes of rash that can affect any part of the body, including the breast, include:

Atopic dermatitis (eczema)
Candidiasis (especially under the breasts)
(a skin infection)
Dermatitis
Hives and angioedema
Psoriasis
Seborrheic dermatitis
Shingles (Herpes zoster infection)

 Breast rash may be accompanied by other localized symptoms including:

Breast lump
Breast pain
Bruising
Itchiness
Pus or discharge
Redness, warmth or swelling
Tenderness or pain

https://www.mayoclinic.org
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