I'm a 16 year old white female and for the past year or so my armpits have gotten a progressively worse light brown color and are sometimes splotchy red.They are very sensitive to shaving and I always get red, sometimes pimple like bumps that stay for a few days. They get itchy when i sweat a lot. I'm not sure what it could be, my mom told me it could be a yeast or bacterial infection. I'm making a dermatologist appointment as soon as I can, but I was trying to get an idea of what it may be.