What should you know about kinds of cysts on skin?

An epidermoid cyst is a common, slow-growing lump filled with keratin and often has a small central opening. A pilar cyst usually forms around a hair follicle, commonly on the scalp. Other cyst-like swellings can arise from blocked glands, inflammation or injury. The label sebaceous cyst is often used casually, although many lumps called that are actually epidermoid cysts.

A cyst may be smooth, mobile and painless, but it can become tender, red or swollen when inflamed or infected. A [Skin Lumps](/symptoms/skin-lumps/) guide can help you describe the change, but appearance alone cannot confirm the type.

Do not pop, pierce or squeeze a cyst; this can spread its contents into nearby tissue and make inflammation worse. Keep the area clean and avoid friction. A quiet cyst may only need monitoring, while an inflamed lesion may be considered for [Steroid Injection Into The Skin](/treatments/injectables/intralesional-steroid-injection/) in selected situations. [Abscess Drainage](/treatments/minor-procedures/abscess-drainage/) may be used when a collection of pus needs release. [Cyst Removal](/treatments/surgical-dermatology/cyst-removal/) can address the cyst wall when complete removal is appropriate.

Arrange a medical review if a lump is new, enlarging, recurrent or uncertain. Seek prompt care for increasing pain, warmth, redness, pus, fever or red streaking, which can indicate infection. A hard, fixed, bleeding or ulcerated lump also needs assessment rather than home treatment. Do not delay review for a cyst near the eye, nose, spine or genitals.

Ask which type of cyst is suspected, whether it is inflamed or infected, whether it can be watched safely, and whether drainage would leave the cyst wall behind. Ask about recurrence, scarring, wound care and what symptoms should lead you back for review.