What should you know about a deep sebaceous cyst?

The term sebaceous cyst is commonly used for an epidermoid cyst, which forms from skin cells trapped below the surface. It may feel smooth, firm, or doughy and can have a small central opening. A deeper cyst may be harder to see or move. If its wall becomes inflamed, the area can turn red, swollen, warm, or painful; this does not always mean there is a bacterial infection. A collection of pus, a lipoma, and other causes of a skin lump can look similar.

Do not squeeze, puncture, or repeatedly massage the lump, as this can irritate the wall and push material into nearby tissue. Keep the skin clean and use a warm, damp compress for comfort if it is tender. A clinician may recommend observation for a quiet, harmless cyst, an intralesional steroid injection for selected inflammation, or Cyst Removal when the cyst recurs, interferes with daily life, or is bothersome. Abscess Drainage is a different procedure used when a pus collection needs to be opened.

Book an appointment for a new, persistent, enlarging, or deep lump so its diagnosis is checked. Seek prompt medical attention if redness spreads, pain becomes severe, the area feels hot, drainage develops, or you feel feverish or unwell. Urgent review is also sensible for a lump near the eye, airway, or genitals, or one that limits movement. These warning features can point to infection or pressure rather than a quiet cyst.

Ask what the lump most resembles, whether it needs imaging or sampling, whether treatment should wait until inflammation settles, and how recurrence and scarring will be handled.