What should you know about a sebaceous cyst on the bra line?

An epidermoid cyst is a keratin-filled sac under the skin. A bra band or strap can repeatedly press against it, trap sweat, and rub the surface, making a previously quiet bump sore. The same area can develop an inflamed follicle, boil, or other skin lump, so the position alone does not confirm a cyst. A clinician may assess whether the lump moves, whether the skin is inflamed, and whether it has changed. You can read more about Skin Lumps.

Choose a clean, well-fitting garment that does not press directly on the lump, and change out of damp clothing after sweating. Wash gently and avoid shaving over the area until it settles. Do not pop or puncture it, because an opening can introduce bacteria and make wound care more difficult. For a recurring or uncomfortable cyst, ask about Cyst Removal. A clinician may consider a Steroid Injection Into The Skin for inflammation or Abscess Drainage when pus has collected.

Arrange medical review if the lump enlarges, becomes hot or increasingly painful, leaks fluid, or repeatedly catches on clothing. Seek urgent care for fever, spreading redness, severe pain, or a rapid change in size. A lump that remains firm and fixed, bleeds, or does not settle after friction is reduced should be examined. These features indicate a need for assessment, not a specific diagnosis.

Is the bra band aggravating the area, and how can I protect it? Does the lump need imaging or another examination? Would observation, an injection, drainage, or removal fit its current state? How can I reduce rubbing during healing?