What should you know about a sebaceous cyst on the back?

An epidermoid cyst forms when skin cells collect inside a small sac below the surface. On the back, it may be hard to see or monitor, and pressure from chairs, backpacks, or lying down can make it noticeable. It may feel smooth and mobile, but a back lump can also be an abscess, lipoma, inflamed follicle, or another condition. A clinician considers the lump's texture, location, skin changes, and history rather than using the nickname sebaceous cyst alone. Skin Lumps provides related information.

Avoid squeezing or puncturing the area; this can release material into the surrounding tissue and make inflammation harder to control. Keep the skin clean, limit pressure and rubbing, and ask someone you trust to help notice changes if the lump is difficult to see. A non-inflamed but troublesome cyst may be discussed for Cyst Removal. During a flare, treatment may involve a Steroid Injection Into The Skin, while a pus-filled collection may need Abscess Drainage.

Book an assessment if the lump is enlarging, repeatedly irritated, or interfering with sleep, movement, or clothing. Seek prompt care for new warmth, spreading redness, marked tenderness, drainage, or fever. Urgent help is appropriate for severe pain, rapidly spreading skin changes, or feeling very unwell. A firm fixed lump, a lump that bleeds, or one that persists without a clear explanation should also be checked.

Does the location and feel fit an epidermoid cyst? Could pressure or friction be contributing? Should it be watched, treated for inflammation, or removed? If it drains, how should I care for the skin and when should I return?