There are a number of causes of bumps in the armpit. That it recently opened up and started oozing purulent fluid is suggestive of an abscess or pilonidal cyst (infected hair follicle). Treatment is with an incision and drainage followed by a course of antibiotics. Alternatively, cysts/lumps in the armpit are suspicious for . . . → Read More: I’ve had a bump under the skin of my armpit for a few months but it hasn’t been red or sore. It recently started oozing whitish, greenish puss with an odor. It’s still not red, nor ever really looked like a pimple. What could it be? Maybe from an ingrown hair?
