Infected cyst on the scalp: what to know

A scalp cyst is a sac beneath the skin that may feel like a rounded lump. When inflamed or infected, it can become tender, warm, red, enlarged, or filled with pus. The lump may be difficult to see through hair, and pressure from sleeping or brushing can make it sore. A clinician checks whether this is a cyst, an abscess, or another type of skin lump.

Inflammation can settle temporarily while the cyst remains, so a quieter lump does not necessarily mean the underlying sac has gone. Do not interpret drainage as proof that all of it has been removed.

Keep the area clean and avoid squeezing, puncturing, or trying to cut the cyst. A warm, damp compress may ease discomfort for a short period; stop if the skin becomes more irritated. Use clean pillowcases and wash hands after touching the area. Do not apply harsh chemicals or someone else’s antibiotics.

A clinician may recommend observation, prescription treatment, drainage, or later removal of the cyst wall. The choice depends on tenderness, pus, size, recurrence, and the condition of the surrounding skin. See the explanation of [Cyst Removal](/treatments/surgical-dermatology/cyst-removal/) for the planned-procedure context.

Seek prompt care if redness is expanding, pain is increasing, pus is draining, or the scalp becomes increasingly warm or swollen. Urgent assessment is appropriate for fever, chills, feeling faint, swelling near the eye or face, severe headache, or confusion. Arrange review for a lump that repeatedly inflames or changes in a new way.

Ask whether the lump is an infected cyst or an abscess, whether drainage is needed, how to protect the area while it heals, and whether removal should be considered after inflammation settles. Ask which symptoms mean you should return sooner.