An armpit rash is often caused by irritation from sweat ... nigricans is a condition often linked to obesity and/or diabetes, and it presents as skin darkening, brown to dark brown in color ...

Armpit rashes often develop due to allergic reactions ... prediabetes, or type 2 diabetes Medication reaction (to birth control pills, corticosteroids, and niacin) Hormonal condition (polycystic ...

Inverse psoriasis is a type of psoriasis that commonly affects the armpits and may cause pain and irritation. Intertrigo may cause a rash under the arms due to inflammation or infection ...