Confused about whether you have a cyst or a pimple? Contact St. Louis Dermatology & Cosmetic Surgery today to find out.
That painful, swollen bump under your skinโฆ is it just a pimple, or something more?
At St. Louis Dermatology & Cosmetic Surgery, one of the most common concerns patients bring to us is a mysterious bump that wonโt go away. Many assume itโs a stubborn pimple, but in reality, it may be aย cyst that requires medical attention.

What is a Pimple?
Pimples are a type of acne lesion caused by clogged pores filled with oil, dead skin cells, and bacteria. They can appear as:
- Whiteheads: clogged pores under the skin
- Blackheads: open clogged pores
- Papules/Pustules: inflamed or pus-filled bumps
- Nodules/Cystic acne: deep, painful acne (not to be confused with true cysts)
Pimples often respond to topical treatments, facials, or prescription medications, and usually resolve within days to weeks.
What is a Cyst?
A cyst is a closed sac beneath the skin filled with fluid, keratin, or other material. The most common skin cysts include:
- Epidermoid cysts (commonly misnamed โsebaceous cystsโ) arise from hair follicles
- Pilar cysts: usually on the scalp
- Sebaceous cysts (less common): come from sebaceous glands
Unlike pimples, cysts do not come to a head and donโt go away on their own. They can remain for months or years and may:
- Grow in size over time
- Become painful or inflamed
- Leak foul-smelling fluid if ruptured
- Get infected
How to Tell If It’s a Cyst or a Pimple
Feature | Pimple | Cyst |
---|---|---|
Size | Small to medium | Medium to large |
Texture | Soft, raised | Firm or rubbery, dome-shaped |
Duration | Days to 2 weeks | Weeks to years if untreated |
Pain | Tender, especially cystic acne | Can be painless or deeply tender |
Location | Face, back, chest | Anywhere (neck, scalp, trunk, genitals) |
Drainage | May pop and release pus | May ooze thick, foul-smelling material if ruptured |
Treatment | Skincare, antibiotics | Often requires surgical removal |
If youโve had a bump that hasnโt gone away after a few weeks or keeps coming back in the same spot, itโs likely a cyst, not a pimple.
When Should You See a Dermatologist
You should book an appointment at SLD in Troy, MO if:
- The bump is growing or painful
- Itโs been present for more than 4 weeks
- It keeps recurring in the same area
- It drains fluid or becomes red and inflamed
- Youโre unsure whether itโs a cyst, pimple, or something more serious

How Are Cysts Removed?
At St. Louis Dermatology & Cosmetic Surgery, cyst removal is typically performed in-office using a quick and minimally invasive procedure:
- Local anesthesia is used to numb the area
- A small incision is made to remove the entire cyst sac (not just drain it)
- The site is closed with sutures or a bandage
- Most patients return to work the same day
Removing the entire cyst wall is critical to prevent regrowth. DIY popping or squeezing can lead to infection, scarring, and recurrence.
FAQ: Cyst vs. Pimple
Can a cyst go away on its own?
Does insurance cover cyst removal?
Can a cyst turn into cancer?
Why Choose SLD for Cyst Evaluation & Removal?
Our board-certified providers serve patients from Troy, Wentzville, Lake St. Louis, St. Charles, and Lincoln County with compassionate, medically sound care.
Whether your concern is aesthetic, uncomfortable, or medically necessary, weโll evaluate your condition and recommend the best path forward. We treat both insured and cosmetic cases, depending on the nature and diagnosis of the cyst.
Ready for an Expert Evaluation?
If youโve been living with a persistent bump that wonโt go away, donโt guess or wait. Let our team at St. Louis Dermatology & Cosmetic Surgery take a look. Contact us today via our contact form orย call us at (314) 834-1400.
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