Are these lumps under my arms HS or just ingrown hairs?

Answered by Eva Taub

The thing I look at first is pattern. A single ingrown hair is usually one bump near a hair follicle that resolves on its own within a couple of weeks. What I see with HS is different — recurring lumps in the same spots over months or years, sometimes connecting under the skin, sometimes rupturing and healing with scarring, most often in skin folds: underarms, groin, under the breasts, inner thighs. If you’re seeing that recurring pattern rather than an occasional single bump, I’d rather you get a dermatologist evaluation now than keep treating it as ingrown hairs indefinitely.