Yellow armpits what's causing it? no odor, acne type welts on lower edge on each side. had tooth extracted last thursday, on amox, motrin, vic

It : It sounds like a possible allergic reaction. Are you having any itching or irritation? Have you recently changed deodorants or are you using any new soaps? Have you had a reaction to Amoxicillin before? This does not sound like an allergy to Amoxicillin but may be possible if it started soon after you began taking it. If you are still symptomatoc consider a visit to your doctor for an evaluation. Good luck.

Meds or vitamins: Medications, even vitamins can cause yellow armpit stains. B vitamins especially b complex can be a factor in yellow stains.