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What Causes Sebaceous Cysts?

The term sebaceous cyst is commonly used for the dermatological condition epidermal cyst. What causes a sebaceous cyst is the increased testosterone that generally happens during puberty. During puberty, hormones cause the increased production of sebum from the sebaceous glands. The most common age group for occurrence includes not only older teenagers but also young adults up to about middle age. Then incidence decreases.
These cysts can also be caused by edematous hair follicles. Follicle glands that are blocked can lead to formation by inflammation, bacteria and fungi. Other causes are improper hygiene, where cysts are blocked by debris on the scalp.

Injury to the hair follicle may become the cause. Perspiring heavily without the benefit of a shower will leave dried fluid and electrolytes on your scalp, which may cause blockage. From there, the cyst may keep growing with additional production of oily substances and the breakdown of keratin, forming a fairly large bump on the skin. This bump is generally painless unless inflammation or infection has developed.


Sebaceous cysts may form on the scalp, neck and upper body. They can also form on the scrotum where they sometimes calcify. Because they are encapsulated in a very thin epidermis layer, rupture is very likely when it can no longer contain the keratin inside. A small opening in the weakest spot of the wall will exude a cheesy, white, or grayish, or yellowish paste.

This is a substance composed of lipid and keratin. It has an unpleasant odor like old, smelly cheese. When a sebaceous cyst ruptures, a cellular reaction may occur to initiate inflammation. At this point, the cyst may become quite painful and tender.


There are only a few things you can do to avoid sebaceous cysts or even what causes sebaceous cysts. If you feel a little lump on your skin and it feels like a pimple, instead of trying to squeeze the pimple apply a very warm, wet cloth to the area. You have to do that several times a day. The warmth and wetness help soften the upper layer that is blocking the opening of the cyst and permit it to open on its own. By squeezing it, you may get it infected and cause much more of a problem. Keep the spot clean at all times.


A sebaceous cyst can be drained of its contents and you may think that this is the end of it. You would be wrong. Since the cyst is encapsulated, chances are very likely that the cyst will fill up again, and again, and again.

Sooner or later, the cyst may burst before it can be drained and begin the inflammatory reaction. Not only will this cause you pain but may end in a more involved treatment which includes antibiotics and perhaps dressings. The most permanent treatment for a large sebaceous cyst is to remove the entire capsule surgically. It is a small procedure and will save you from big lumps in the future. Most sebaceous cysts are single cysts although you could encounter several in the same individual.