Dr. BHB - identity rash under breast?

For about a week I've had this discolored area under my breast that itches and has bumps on it. I usually wear sports bras, I'm thinking maybe a sweat buildup…

Any large chested ladies get a rash under breast?? (Sorry - pic included)

Rash Under Breast (Interigo): Causes, Treatment, and More

Rashes Under the Breasts – Cottonique - Allergy-free Apparel

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HOW TO TREAT UNDER BREAST RASHES + INFECTION NATURALLY IN 4 EASY STEPS, INTERTRIGO

Ask the doctor: Should I be worried about the weird rash under my breasts?

Rash Under Breast (Interigo): Causes, Treatment, and More

Rash under breast: Causes, treatments, and more

What Causes a Rash Underneath the Breast? Breast Reduction Center Virginia at Richmond Aesthetic Surgery

Under boob rash (pics included)

Un jeune enseignant chercheur ''recadre'' Dr Ousmane Kaba : ''Docteur, la reconnaissance d'un diplôme dépasse les compétences du CAMES'' - Accentguinee

Rash Under Breast: Causes, Treatment, and Prevention