Epidermoid Cyst - Symptoms, Causes & Treatment
By ScanSkinAI Editorial Team✓ Reviewed for medical safetyLast updated June 2026
A slow-growing, benign cyst that develops from skin cells trapped beneath the surface. They're filled with keratin and have a visible central punctum.
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Quick Answer
An epidermoid cyst is a slow-growing, harmless lump that forms when skin cells get trapped beneath the surface. These smooth, movable bumps are filled with keratin—a protein that makes up your hair and nails. You might notice a small dark opening in the centre, which can sometimes release a thick, strong-smelling substance if squeezed. Most epidermoid cysts do not require any treatment. However, if the cyst becomes painful, swollen, or red, it is a good idea to consult a healthcare professional for proper evaluation and care.
Symptoms
- Round, movable lump under skin
- Central punctum (blackhead-like opening)
- May have cheesy, smelly discharge if squeezed
- Can become inflamed or infected
Causes & Risk Factors
- Blocked hair follicle
- Skin trauma
- Developmental
- Not truly related to sebaceous glands
Treatment & Management
- Often no treatment needed
- Surgical excision (including cyst wall)
- Incision and drainage if infected
- Steroid injection for inflammation
When to See a Doctor
If cyst becomes painful, red, or rapidly enlarges
Frequently Asked Questions
What does an epidermoid cyst look and feel like?
It usually feels like a firm, round, smooth lump just beneath your skin that you can move slightly with your fingers. Commonly, there is a tiny blackhead-like plug in the centre, known as a punctum. If irritated or squeezed, the cyst might ooze a thick, yellowish material that has a noticeable odour.
How did I get this cyst in the first place?
These cysts happen when surface skin cells move deeper into your skin and multiply instead of shedding naturally. This can occur after a minor skin injury, severe acne, or a blocked hair follicle. The trapped cells continue to produce keratin, a thick protein, which gradually fills up the cyst over time.
Is a sebaceous cyst the same thing?
People often use the term sebaceous cyst to describe these lumps, but that is technically incorrect. True sebaceous cysts are rare and start from the glands that produce your skin's oils. Epidermoid cysts are far more common and are filled with keratin hair and skin proteins, rather than oily sebum.
Will the cyst go away on its own, or do I need it removed?
An epidermoid cyst usually will not disappear completely on its own, but treating it is often unnecessary if it is small and painless. If the lump bothers you or becomes inflamed, a doctor can safely remove it. For a permanent solution, the entire cyst wall or sac must be surgically removed; otherwise, it is likely to grow back.
Is it safe for me to pop or squeeze the cyst?
You should never try to pop, squeeze, or drain a cyst at home. Squeezing can force the keratin material deeper into your skin, leading to severe inflammation, pain, and a much higher chance of infection. Squeezing also leaves the cyst wall intact inside your skin, meaning the lump will almost certainly return.
When should I have a doctor look at my skin lump?
You should see a healthcare professional if the cyst rapidly grows, becomes painful, turns red, or feels unexpectedly warm to the touch. These are common signs of inflammation or infection. A doctor can properly evaluate the lump, prescribe any necessary treatments like antibiotics or steroid injections, or perform an incision to drain the area safely.
Could this lump actually be a sign of skin cancer?
Epidermoid cysts are almost always completely benign, meaning they are not cancerous. However, any new or changing lump on your skin should be checked by a medical professional to be absolutely sure. While serious conditions are rare in this context, a proper medical exam is the only way to rule out other types of skin growths completely.
How can ScanSkinAI help me keep track of an epidermoid cyst?
ScanSkinAI is a helpful screening aid that allows you to easily track the size, colour, and changes of your skin lumps over time. While the AI can help flag unusual visual patterns, it cannot diagnose an epidermoid cyst or any other condition. Always share your scanning results with a qualified healthcare provider for an official diagnosis and treatment plan.
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Medical References
Information on this page is sourced from and verified against reputable medical resources:
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Medical Disclaimer: This information is for educational purposes only and is not intended as medical advice. The content on this page should not be used to diagnose or treat any health problem. Always consult with a qualified healthcare professional for proper medical evaluation, diagnosis, and treatment of your condition.