Sebaceous cysts are sacs just beneath the skin that are filled 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.
Sebaceous cysts tend to develop in teenagers because of an interaction among hormones, sebum, and bacteria. During puberty, the glands in the skin 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. A comedone may break through the pore wall underneath the skin and release its contents. This causes a pimple or pustule. If this substance is released deep into the skin it will cause a sebaceous cyst.
There is no known cause for sebaceous cysts. Acne, which leads to sebaceous cysts in some individuals, is caused by four factors:
Virtually every adolescent experiences some comedones, or clogged pores. Generally, acne starts around the age of 10 to 13 years and lasts 5 to 10 years. Around the age of 14 or 15 years, approximately 40% of adolescents have acne that is serious enough to require a visit a healthcare provider. Acne happens in both male and female adolescents, but males are more likely to have a severe form of acne. Some people develop acne for the first time as an adult.
Certain forms of acne tend to run in families. If an adolescent's parents or older siblings have severe acne, the adolescent has a higher risk of developing severe acne. Acne is more common in Caucasian Americans than in African Americans or people of Asian descent.
Risk factors that increase an individual's risk for development or worsening of acne include the following:
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.
The healthcare provider can diagnose a sebaceous cyst with a medical history and physical examination. The cyst is compared to the person's normal sebaceous glands.
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:
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.
Sebaceous cysts are not contagious and pose no risk to others.
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.
Antibiotics can cause rash, stomach upset, or allergic reactions. Surgery to remove a cyst can cause bleeding, infection, or allergic reaction to anesthesia.
There are few complications from sebaceous cysts. An untreated cyst can cause a skin abscess, or infection in the underlying soft tissue. Cysts do tend to recur, even when the sac has been removed. If even a small portion of the sac is left, the cyst can recur.
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 provider.
Author:James Broomfield, MD
Editor:Ballenberg, Sally, BS
Reviewer:Eileen McLaughlin, RN, BSN
Complete Guide to Symptoms, Illness, and Surgery, Griffith, 2000
Taber's Cyclopedic Medical Dictionary, 1989