Sebaceous Cyst on the Back of the Neck: What to Know

The term sebaceous cyst is commonly used for an epidermoid cyst. It is a pocket beneath the skin containing keratin, a protein made by skin cells. A cyst can feel smooth, firm, or slightly movable, and some have a small central opening. Friction from shirt collars, hair, or a pillow can irritate a cyst in this area. It is different from an abscess, although a cyst can become inflamed or infected and then look red, swollen, and feel painful.

A new or changing lump belongs in the wider category of skin lumps, especially when its appearance is unclear.

Do not squeeze, puncture, or repeatedly press the lump. Those actions can push material deeper, break the cyst wall, and increase irritation. Keep the skin clean and reduce rubbing from tight collars or straps. A clinician can examine the lump and decide whether observation is reasonable, whether an inflamed cyst needs calming treatment, or whether removal is appropriate. Drainage may relieve an abscess, but removing the cyst wall is what helps address the pocket itself.

Arrange a prompt assessment if the lump becomes rapidly larger, hot, increasingly painful, very red, or starts releasing pus or foul-smelling fluid. Seek urgent help if redness spreads, you feel feverish or unwell, or neck swelling interferes with swallowing or breathing. A painless lump that persists, repeatedly returns, bleeds, or changes in texture also deserves a clinician’s review.

Ask whether the lump looks like an epidermoid cyst, whether inflammation or infection is present, and whether the location makes removal advisable. You can also ask what warning changes to watch for and how a procedure might affect the skin at the back of your neck.