Pimples in the armpit: what to know

Armpit skin is warm, moist and exposed to rubbing, shaving and deodorant ingredients. A small red bump around a hair may be folliculitis or an ingrown hair; acne can also affect the area. A tender lump under the skin, repeated nodules, drainage or scars may point to a longer-term inflammatory condition rather than an ordinary spot. A swollen lymph node can feel like a lump but is not a pimple.

Clean the area gently and dry it thoroughly. Wear breathable clothing, change out of sweaty garments, and pause shaving or waxing while bumps are active. Stop any deodorant that burns or causes a rash, then reintroduce products one at a time after recovery. Do not squeeze, pierce or share towels or razors. A clinician can advise whether a cleanser or medicine is appropriate, especially if there is pus, repeated inflammation or sensitive skin.

Make an appointment if a lump keeps returning, grows, drains, scars, limits arm movement or fails to improve after avoiding friction. Seek prompt care for rapidly spreading redness, severe pain, marked swelling, red streaks or fever. An examination matters when several lumps occur, because treatment differs between folliculitis, acne, irritation and deeper inflammatory disease.

Is this folliculitis, an ingrown hair, acne or a deeper lump? Could shaving or deodorant be contributing? What should I use during a flare, and how can I prevent repeated episodes?