Cysts behind the ears are almost always epidermoid cysts, the most common type of skin cyst. They form when a hair follicle gets plugged and skin cells start building up beneath the surface instead of shedding normally. The area behind your ear is particularly prone because it has numerous hair follicles and oil glands packed into a small, warm, often-neglected patch of skin.
What’s Actually Happening Under the Skin
Every hair follicle has a tiny opening at the skin’s surface. When that opening gets blocked, the skin cells lining the follicle keep producing keratin, a protein that normally sheds away. With nowhere to go, the keratin accumulates and forms a slow-growing pocket beneath the skin. This pocket is lined with the same type of tissue as your outer skin, which is why it keeps producing material and can gradually expand over months or years.
The cyst stays connected to the surface through a small, often barely visible pore. If you’ve ever noticed a tiny dark dot at the center of a cyst, that’s the plugged opening. The contents inside are dense, off-white, and often have a strong smell, which is compacted keratin, not pus (unless the cyst has become infected).
Why the Area Behind Your Ear Is Vulnerable
Several factors make the postauricular area (the skin just behind the ear) a hotspot for cysts. The skin there is rich in sebaceous glands, which produce oil to keep your skin and hair lubricated. When sebum production is high, gland ducts can become blocked more easily. Hormones, particularly androgens like testosterone and DHT, directly control how much oil these glands produce. This is why cysts in this area often first appear during puberty or during hormonal shifts.
People who are prone to acne tend to produce more sebum overall, and the composition of their sebum is different. They have higher levels of a compound called squalene, which oxidizes and irritates the skin, and lower levels of linoleic acid, a fatty acid that helps keep pores clear. This combination makes follicular plugging more likely across the body, including behind the ears.
The area behind your ear also collects sweat, product residue from shampoo or hair styling, and dead skin cells. It’s easy to miss during washing. Friction from glasses, earbuds, headphones, or even pillowcases can irritate hair follicles and contribute to blockages. Any prior injury to the skin there, even something minor like a scratch or a piercing, can push surface skin cells deeper into tissue where they don’t belong, seeding a cyst that shows up weeks or months later.
Other Lumps That Aren’t Cysts
Not every bump behind the ear is a cyst. Swollen lymph nodes are the most common cause of postauricular swelling, and they can feel surprisingly similar to a cyst. You have a cluster of lymph nodes just behind each ear, and they swell in response to nearby infections. A cold, ear infection, scalp infection, or even a bug bite on the scalp can trigger noticeable swelling. Unlike a cyst, a reactive lymph node typically appears quickly (over a day or two), feels tender, and shrinks on its own once the infection resolves.
Mastoiditis is a more serious possibility, though far less common. This is a bacterial infection of the mastoid bone directly behind the ear, usually following a middle ear infection. The signs are distinct: throbbing ear pain that won’t let up, fever, pus draining from the ear, redness or swelling that makes the ear stick out, and sometimes hearing loss, dizziness, or confusion. Mastoiditis requires prompt medical treatment and is not something that resembles a typical painless cyst for long.
Lipomas (soft fatty lumps) and, rarely, skin cancers can also appear in this area. A lump that is hard, fixed to deeper tissue (doesn’t move when you press it), grows rapidly, or changes the overlying skin warrants evaluation. A typical epidermoid cyst, by contrast, is round, moves slightly under the skin when touched, and grows slowly over weeks to months.
Why Cysts Keep Coming Back
If you’ve had a cyst drained or squeezed and it returned in the same spot, that’s expected. Every epidermoid cyst has a lining, a thin sac of skin tissue that acts like a factory for keratin. Draining the cyst empties the contents but leaves the sac intact. As long as that lining remains, the cyst will refill over time. This is the single biggest reason people deal with recurring cysts behind the ear.
Some people are also genetically predisposed to forming multiple cysts. If you have a history of acne or a family tendency toward cysts elsewhere on the body, the skin behind your ears may simply be more prone to follicular plugging.
How Cysts Are Treated
Most small, painless cysts behind the ear don’t require any treatment. They’re benign and pose no health risk. Many people choose to leave them alone unless they become bothersome.
When treatment is needed, there are two approaches. Drainage involves making a small opening and pressing out the contents. This provides immediate relief if the cyst is large, painful, or infected, but it’s a temporary fix. The cyst will likely return because the sac is still in place. Surgical excision removes the entire cyst, including the lining. This is a minor outpatient procedure done under local anesthesia, and it significantly lowers the chance of recurrence. The key factor in preventing a cyst from coming back is complete removal of that inner sac.
If a cyst becomes red, warm, swollen, and painful, it may be infected. Infected cysts sometimes need to be drained and treated with antibiotics before full excision can be done, since removing an actively infected cyst is more difficult and heals less cleanly.
Reducing Your Risk
You can’t entirely prevent epidermoid cysts, especially if you’re genetically prone to them. But you can reduce the conditions that encourage follicular plugging behind your ears.
- Clean the area intentionally. When washing your face and hair, make a habit of gently scrubbing behind your ears with a mild cleanser. This removes accumulated oil, dead skin, and product residue.
- Exfoliate gently. A weekly pass with a soft washcloth or gentle exfoliant helps prevent the buildup of dead skin cells that can block follicles.
- Choose non-comedogenic products. Hair gels, sprays, and moisturizers labeled “non-comedogenic” or “oil-free” are less likely to clog pores in the area.
- Minimize friction. If you wear glasses, over-ear headphones, or earbuds for long periods, give the skin behind your ears a break. Wipe down anything that presses against the area regularly.
- Treat skin injuries carefully. Clean cuts, scratches, or piercing sites behind the ear promptly. Skin cells pushed below the surface during an injury can become the origin of a new cyst.
If you’re dealing with acne-related cysts, addressing the underlying acne through a consistent skincare routine or dermatological treatment can reduce cyst formation across all affected areas, including behind the ears.