Steatocystoma multiplex is a rare condition in which many small cysts filled with sebum appear on the skin. Cysts are hollow lumps, and sebum is an oily substance produced by the sebaceous glands that are found near hair roots. Steatocystoma multiplex is an inherited disease but cases can also occur where there is no family history of the condition. The cysts usually develop during adolescence. Alternative names for the disorder include sebocystomatosis and epidermal polycystic disease and, in cases where only a single cyst develops, the disease is known as steatocystoma simplex. Although steatocystoma multiplex is not malignant, or cancerous, it can be disfiguring.
People with steatocystoma multiplex often have a parent with the disease. Most often, the distribution of cysts corresponds to those areas of the body which have the greatest numbers of sebaceous glands, such as the skin of the chest, neck and arms. The cysts are thought to arise from abnormal development in those areas where the ducts, or passages, that drain sebaceous glands join on to hair follicles. Cysts are usually skin-colored, or slightly yellow, and less than 1.18 inches (about 3 cm) in diameter, but occasionally a larger one may develop. An individual cyst may be firm or slightly soft to the touch, and a creamy yellow substance is found inside.
In the absence of complications, the cysts do not cause any symptoms, but sometimes steatocystoma multiplex may be complicated by infection, causing a discharge which smells unpleasant. A cyst may burst, become inflamed and form drainage channels, leading to scarring. Even if complications occur, because each growth is a benign cyst, meaning that it is not cancer, the outlook for someone with the disease is very good, and steatocystoma multiplex treatment focuses on reducing any inflammation or scarring which may be associated with the condition. Treatment may involve the use of medications such as antibiotics, and individual cysts may be cut open and drained.
If drug treatment is not successful, surgery may become necessary and a variety of techniques may be used to manage steatocystoma multiplex. Draining cyst contents using a syringe and needle may be beneficial for smaller cysts or those on the face. This method can lower the risk of scar formation, and the cysts often do not recur. Larger cysts may be completely removed by cutting out the cyst wall as well as removing the contents. Laser therapy, where a beam of light energy is used to vaporize tissue, is another method which can successfully destroy cysts.