What should you know about red sebaceous cyst?

The term sebaceous cyst is commonly used for an epidermoid cyst, a sac beneath the skin that can contain keratin. Friction or pressure may make it sore and red. If bacteria enter, the area may become increasingly warm, painful, swollen, and filled with pus; this can resemble an abscess. A lump that repeatedly drains may still have its lining present, so it can return after temporary relief.

A new or changing lump should be examined rather than diagnosed by appearance alone. Do not confuse a cyst with every other type of skin lump.

Keep the area clean, protect it from rubbing, and use a warm—not hot—compress for comfort. Do not squeeze, pierce, or attempt to empty it at home. A clinician may discuss an intralesional steroid injection for selected inflammation, abscess drainage when a collection needs releasing, or cyst removal when the whole sac needs treatment. The suitable option depends on examination and timing.

Arrange prompt review for increasing pain, warmth, swelling, pus, bad smell, or difficulty moving the nearby area. Seek urgent care if redness spreads quickly, fever or chills develop, red streaks appear, or the cyst is near the eye or spine. Emergency help is needed for severe illness or breathing difficulty.

Ask whether the lump is an epidermoid cyst or abscess, whether drainage is needed, how to dress it, and whether cyst removal should be considered after inflammation settles.