Definition
Sebaceous cysts form when a sac just beneath the skin surface, usually a hair follicle, fills with an oily, white, semisolid material called sebum. If the sebum becomes infected, the cyst will be red and painful. Sebaceous cysts are commonly seen on the scalp, labia, scrotum, chest, and back, but can be found anywhere on the body.
What is going on in the body?
Sebaceous cysts tend to develop in teenagers because of an interaction among hormones, sebum, and bacteria. During puberty, the glands in the hair follicles produce excessive sebum. In skin that is prone to acne, the sebum and dead skin cells clog the hair follicles and form comedones, or clogged pores.
What are the signs and symptoms of the condition?
A sebaceous cyst is a dome-shaped lump with a smooth surface. It typically measures 1 to 5 centimeters. The cyst is usually white or the same color as the skin. These cysts can become irritated by clothes rubbing against them or by shaving. They may become bright red, swollen, and painful if infected.
What are the causes and risks of the condition?
There is no known cause for sebaceous cysts. Acne, which leads to sebaceous cysts in some individuals, is influenced by various factors:
hormones, particularly the hormone called androgen
increased production of sebum, the oily substance within the hair follicles
changes in the lining of the hair follicles
bacteria and other organisms, which cause infections and inflammation when they are trapped within the hair follicles
Risk factors that increase an individual's risk for development or worsening of acne include the following:
makeup and skin care products, which can clog the hair follicles
menstrual cycles, which make acne flare-ups more likely in women when their glands are more sensitive to the hormone androgen
airborne grease, such as in a fast food restaurant
routine exposure to products such as motor oil, such as in an automotive shop
rubbing and friction of the skin by hair, clothing, or sporting equipment
What can be done to prevent the condition?
There are no known measures to prevent sebaceous cysts. Acne, which may be a precursor to cysts, can be minimized by taking the following steps:
Wash the face twice a day with a mild soap, and pat it dry.
Avoid picking, squeezing, or popping comedones, pimples, pustules, and cysts. This type of manipulation actually makes the acne worse.
Select skin care products, such as makeup, foundations, moisturizers, and creams, that are labeled noncomedogenic, meaning that they do not clog pores.
Avoid prolonged exposure to oil and grease in settings such as fast food restaurants and automotive shops.
Avoid unnecessary friction from hair, clothing, or sporting equipment.
How is the condition diagnosed?
The healthcare professional can diagnose a sebaceous cyst with a medical history and physical examination. The cyst is compared to the person's normal sebaceous glands.
What are the long-term effects of the condition?
In most people, sebaceous cysts are benign and cause no problems. But in some people, the cysts can become infected or can rupture, causing swelling and pain.
What are the risks to others?
Sebaceous cysts are not contagious and pose no risk to others.
What are the treatments for the condition?
In most cases, no treatment is needed for sebaceous cysts. The cysts are usually small and are not bothersome at all. Sebaceous cysts may disappear on their own, or they may remain in the same place at the same size without causing any problems.
Some cysts are annoying because they rub against clothing. They may be unsightly or may become infected. In these cases they may need to be drained with a small incision. Larger cysts may be removed entirely. The cyst and the sac around it are removed to prevent recurrence. Oral antibiotics, such as cloxacillin or erythromycin, may be given as part of the treatment for an infected cyst.
What are the side effects of the treatments?
Antibiotics can cause rash, stomach upset, or allergic reactions. Surgery to remove a cyst can be complicated by bleeding, infection, or an allergic reaction to the anesthetic.
What happens after treatment for the condition?
There are few complications from sebaceous cysts. An untreated cyst can cause a skin abscess, or infection in the underlying soft tissue. Cysts tend to recur, even when the sac has been removed, if even a small portion of the sac is left behind.
How is the condition monitored?
Sebaceous cysts can be monitored by watching the size of the cyst and noting any redness or swelling that may indicate infection. Any new or worsening symptoms should be reported to the healthcare professional.
Author: James Broomfield, MD Date Written: 01/14/00 Medical Review: David McDaniel, MD Date Written: 1/8/2007 Reviewer: Reginald Finger, MD Date Reviewed: 1/10/2007
Contributors
Potential conflict of interest information for reviewers available on request
