What are Skin Cysts?
A skin cyst (also called an epidermal inclusion cyst or sebaceous cyst) is an enclosed capsule inside the skin that is filled with keratin. They are frequently a result of clogged pores or hair follicles, and are common in areas such as the scalp, neck, shoulder, or back as a result; however, it is possible for cysts to appear anywhere else on the body as well.
The vast majority of skin cysts are usually only a cosmetic concern and aren’t life threatening; however, they can be uncomfortable and can get inflamed or infected. Cysts in the scalp for instance can get irritated by a comb while styling hair and can cause pain. Cysts in the shoulder or back can create an unsightly lump that is easily noticeable, and can interfere with daily routines such as putting on a seatbelt or wearing a backpack. If left untreated, it is also possible for cysts to become infected. Infected cysts become red due to inflammation, and can develop an unpleasant smell due to the presence and leaking of pus or keratin.
Causes
The causes of skin cysts are not 100% certain. Many of them develop simply due to genetics. Multiplying cells move inwards as opposed to moving away from the skin’s surface and shedding away like normal. Skin cysts can also develop from some form of damage that causes epidermal skin cells to be implanted in the dermis.
Some of the common causes are:
- Ingrown hairs
- Genetics
- Infections
- Blockage of ducts in body
- Parasites
- Injuries
- Errors in embryonic development
Other common causes include blocked sebaceous glands, high levels of testosterone, and the use of androgenic anabolic steroids.
Epidermal inclusion cysts are extremely common, and may be due to damage to a hair follicle or oil gland. These types of cysts are often benign, and are a buildup of keratin below the skin’s surface. Epidermoid cysts that involve damage to a hair follicle are known as pilar cysts, and more than 90% of pilar cysts occur in the scalp. It is very common for multiple pilar cysts to be present at the time time.
Dermoid cysts are growths present at birth. These are derived from residual embryonic cells from the epidermis becoming trapped during fetal development. Because they grow slowly, many people notice them for the first time during childhood or early adulthood.
Sebaceous cysts are usually rare. These contain a buildup of sebum in the sebaceous glands. Multiple ones commonly form at once (known as steatocystoma multiplex), but can also be find in single instances as well (steatocystoma simplex). Sebaceous cysts can occur inside of a pore or hair follicle on the back, face, or scalp. Due to them containing sebum, as well as their location, they can grow to be a very large size and can cause pain and pressure.
Signs & Symptoms of Cysts
Epidermoid, dermoid, and sebaceous cysts frequently consist of benign swelling in the skin from the sebaceous gland or hair follicle. They are filled with a yellowish substance known as either keratin of sebum, depending on the type of cyst. This substance has a consistency that is comparable to cottage cheese. Oftentimes they are easily visible due to the swelling, and can cause pain if large enough.
Many cysts are asymptomatic and don’t have any visible signs. They can be seen & felt as a lump or bump in an area of the skin. They can sometimes cause pain if a cyst is infected or irritated, although many cysts have no pain. The easiest way to determine if a lump is a possible cyst is if it can be freely moved around within the skin.
If a cyst is not visible, they can be diagnosed via ultrasound, x-ray, medical scans, or a biopsy. Because cysts can become infected, they can become swollen and tender, and may even develop a pustule. Permanent scarring or discoloration can also happen if a cyst is left untreated for extended durations. While most cysts are harmless, a cyst that has burst or otherwise leaked out of its capsule has a very high risk of infection, can lead to other problems.
It is important to note that cysts can be commonly confused with other conditions, such lipomas. Acne cysts are a collection of inflamed and clogged skin oil ducts. These are considered to be an abscess instead since the sac is filled with pus instead of keratin or sebum, and require different treatment methods.
Cysts that are located behind the ear or around an area where an injury occurred can by mistaken as a keloid instead.
Certain cases of basal cell carcinoma can mimic a cyst, but are actually a skin cancer. A professional examination from a board-certified dermatologist such as Dr. Behroozan can ensure that the condition is properly identified, and can be treated with the appropriate methods.
Treatment
The most common treatment for skin cysts is removal via excision. The excision process is an out-patient surgical procedure that is quick, and can often be completed in about 10 minutes.
