Pimple Under Skin In Armpit. Your skin is continually shedding tiny flakes and milia under your arms occurs when the dead flakes are trapped in small pockets near the surface of your skin. According to Doctors on WebMD lipomas are usually small soft bumps under the skin that appear in the armpits upper body thighs and upper arms.

Milia is sometimes called baby acne even though it has no connection to that skin problem. An armpit lump or axillary lump is often caused by swollen lymph nodes in the armpit. Typically pimples in the armpit or underarm are not actually acne says South Carolina-based board-certified dermatologist Dr.
4 An unnamed woman.
Milia is sometimes called baby acne even though it has no connection to that skin problem. A small or pea-sized lump in the armpit can also be caused by a skin infection like a cyst or ingrown hair. Your skin is continually shedding tiny flakes and milia under your arms occurs when the dead flakes are trapped in small pockets near the surface of your skin. The hair that gets trapped in the skin can cause swelling in the armpits.