Cutaneous Cysts

Overview

A cutaneous cyst is a benign, saclike growth containing fluid or semi-solid material that forms beneath the skin. Most cysts are harmless, although some can enlarge and become swollen and painful.

Types of Cysts

The most common types of cutaneous cysts are sebaceous, or epidermoid, cysts and pilar cysts. Sebaceous cysts usually form on the body or face, and less commonly on the arms and extremities, of people with oily skin. Pilar cysts are round, large nodules that typically appear on the scalp.

Causes

Most cysts appear spontaneously, and it is not fully understood why they form. Cutaneous cysts form from the lining of hair follicles that have become blocked for some reason. Cysts that are inflamed or painful may be the result of leaks or ruptures of the cyst beneath the skin.

Treatment

Many cysts will not require treatment, and may disappear on their own. Large cysts that are causing discomfort may be treated with an injection of cortisone into the lesion, or with a surgical incision and removal of the sac at the center of the cyst. Cysts that are inflamed or painful may indicate infection and may be treated with oral antibiotics and surgical removal.