Differential Diagnosis for Under Breast Rash

• Single most likely diagnosis
  • Intertrigo: This is the most common cause of under breast rash, especially in warm and humid environments. It is a type of skin inflammation caused by friction, heat, and moisture, making the area under the breast prone to this condition.
• Other Likely diagnoses
  • Candidiasis: A fungal infection that thrives in warm, moist areas, making the under breast area susceptible, especially in individuals with diabetes or those who are immunocompromised.
  • Contact dermatitis: This can occur due to irritation from clothing, soaps, or other substances that come into contact with the skin under the breast.
  • Eczema (atopic dermatitis): Can manifest in the under breast area, especially in individuals with a history of atopic diseases.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Inflammatory breast cancer: Although rare, it presents with skin changes such as redness, swelling, and sometimes a rash, which can be mistaken for an infection or other benign conditions. Early diagnosis is crucial.
  • Cellulitis: A bacterial infection of the skin that can spread rapidly and become serious if not treated promptly.
• Rare diagnoses
  • Granulomatous lobular mastitis: A rare inflammatory condition of the breast that can cause skin changes and rashes.
  • Paget's disease of the breast: A rare form of breast cancer that can cause eczema-like changes to the skin of the nipple and, occasionally, the surrounding area, including under the breast.