A sebaceous cyst occurs when the opening of an oil gland in the skin becomes blocked. The gland swells with skin oil and dead skin cells. As it gets bigger, it looks like a small, painless lump under the skin. Sometimes the cyst can get infected. When the infection is limited, it can be treated with antibiotics alone. If the infection does not clear up with antibiotic treatment, the cyst will need to be drained by making a small incision using local anesthesia.
A sebaceous cyst is a term that most commonly refers to 2 types of cysts: “epidermoid” (from skin), and “pilar” (from hair follicles). Here is some information about these cysts:
A cyst is a sac filled with material that is often cheesy, fatty, oily, or fibrous material. The material in them can be thick (like cottage cheese) or liquid.
Sebaceous cysts form slowly under the skin, and can be found on most parts of the body. They are most commonly found in hairier areas like the scalp, face, upper back, and genitals.
You can usually move the cyst slightly if you try.
The cysts can be smaller than a pea or as large as a couple of inches.
The cysts are usually not painful, unless they become inflamed or infected.
The area around the cyst may smell bad. If the cyst breaks open, the material inside it often smells bad as well.
While these cysts often go away without any treatment, they can get infected. If they drain by themselves, they may return. Resist the temptation to squeeze, pop, stick a needle in it or cut it open. This often leads to an infection and scarring. If the cyst gets severely inflamed or infected, you should seek medical treatment.
When the infection is early, and the size and location are limited, it can sometimes be treated with antibiotics alone. If the infection does not clear up with antibiotics and warm compresses, the cyst will need to be drained by making a small incision using local anesthesia.
The following guidelines will help you care for your wound at home:
Again, resist the temptation to squeeze, pop, stick a needle in it, or cut it open; this often leads to a worsening infection and scarring.
Take the antibiotic as directed until it is all used up.
Soak the involved area in hot water or apply hot packs (small towel soaked in hot water) for 20 minutes at a time 3 to 4 times a day.
Apply antibiotic cream or ointment 3 times a day.
You may use acetaminophen or ibuprofen to control pain, unless another medicine was given. If you have chronic liver or kidney disease or ever had a stomach ulcer or GI bleeding, talk with your doctor before using these medicines.
Once this infection has healed, observe the following to reduce the risk of future infections:
Keep the area of the cyst clean by bathing or showering daily.
Avoid tight fitting clothing in the area of the cyst.
Follow up with your doctor as advised by our staff. If a gauze packing was inserted in your wound, it should be removed in 1–2 days. Check your wound every day for the signs listed below.
Get prompt medical attention if any of the following occur:
Pus coming from the cyst
Increasing redness around the wound
Increasing local pain or swelling
Fever of 100.4°F (38ºC) or higher, or as directed by your health care provider