Epidermal Inclusion Cyst of the Scalp: What to Know

The lump may be round, smooth, and mobile under the scalp. It can have a small surface opening, although this is not always visible through hair. Keratin inside the pocket is a skin protein, not liquid oil. A pilar cyst can look similar, so the name cannot be confirmed from appearance alone. Irritation, pressure, or rupture can bring inflammation, producing tenderness, warmth, redness, swelling, or thick discharge. These changes do not establish the diagnosis without an examination.

Leave the cyst alone and avoid squeezing it or trying to drain it with a needle. Use gentle scalp care and protect it from repeated friction during brushing or headwear. Book a dermatology review if it is enlarging, repeatedly irritated, difficult to distinguish from another lump, or interfering with grooming. If treatment is chosen, complete removal of the sac may be discussed; drainage can relieve pressure but may not remove the pocket.

Arrange prompt care for rapidly increasing pain, redness, warmth, swelling, foul-smelling drainage, or fever. Urgent assessment is appropriate if redness spreads, pain is severe, or you feel faint or very unwell. Any scalp lump that is fixed, ulcerated, bleeding, or changing in an unusual way should be examined rather than self-treated.

Ask whether this is more consistent with an epidermal inclusion cyst or a pilar cyst, whether it is inflamed, and what treatment suits its position on the scalp. Clarify wound care, hair washing, expected tenderness, and what to do if the lump returns.