What Is a Sebaceous Cyst?
A sebaceous cyst is a small lump or bump under the skin. This type of cyst is not cancerous.
They are most often found on the face, neck, upper back, and upper chest, but can occur on other sites of the body as well.
Usually a sebaceous cyst grows very slowly and doesn’t cause pain.
However, they can become inflamed or infected, with the overlying skin becoming red, tender, and sore.
Sometimes, they occur on a site that is constantly irritated, such as a cyst on your neck that rubs against your collar.
In those cases, treatment can help reduce discomfort.
A cheesy, bad-smelling material sometimes drains from the cyst. And they can look bad cosmetically, especially if one develops on your face.
Causes of a Sebaceous Cyst
Sebaceous cysts and epidermoid cysts are often talked about interchangeably, but they are different.
True sebaceous cysts arise from hair follicles, whereas epidermoid cysts develop from skin cells.
Sebaceous cysts often occur after a hair follicle becomes swollen.
The cysts originate from the sebaceous glands, the glands that secrete the oily matter (sebum) that helps to lubricate the skin and the hair.
Epidermoid cysts originate from the skin. The surface of your skin, known as the epidermis, consists of thin layers of cells. You constantly shed the cells.
However, when the cells move deeper into your skin instead of shedding, they can multiply, leading to cyst formation.
The cells that form the walls of the cysts secrete a protein, keratin, into the cyst. When the cyst drains, the secretions can be foul-smelling.
These cysts are sometimes hereditary. For instance, steatocystoma multiplex is a rare inherited disorder in which multiple sebaceous cysts form.
Cysts can remain small for years or they can keep growing larger. In other cases, a sebaceous cyst can disappear on its own.
Sebaceous Cyst Treatment
If a sebaceous cyst does not cause problems or look bad cosmetically, you probably don’t need any treatment.
If it becomes swollen or tender, home treatments may help. Putting a warm moist compress over the cyst may help it drain, for instance.
Resist any temptation to pop or squeeze the cyst, like a pimple.
But if it’s inflamed and causing discomfort, you should see a doctor.