What Causes Multiple Pilar Cysts On The Scalp?

Multiple pilar cysts on the scalp are caused by a combination of genetics and the natural behavior of hair follicle cells. These cysts form when cells from the outer root sheath of a hair follicle multiply and fill with keratin instead of rising to the surface and shedding. When you have multiple cysts, the most likely explanation is an inherited genetic mutation, often linked to a condition called steatocystoma multiplex or familial pilar cyst syndrome.

What Exactly Is a Pilar Cyst and How Is It Different From Other Scalp Lumps?

A pilar cyst is a firm, round bump that grows under the skin of the scalp. It feels smooth and can move slightly when pressed. The cyst wall is made of cells that normally line the hair follicle, and the inside is filled with a soft, cheesy substance made of keratin—the same protein in your hair and nails.

Pilar cysts are not the same as sebaceous cysts, which come from oil glands. Sebaceous cysts are rare on the scalp. Pilar cysts are much more common there. They are also not the same as epidermoid cysts, which form from the outer layer of skin. Pilar cysts specifically come from the hair follicle sheath.

Most pilar cysts are benign. They grow slowly and do not turn into cancer. The main reasons people have them removed are because they look noticeable, feel uncomfortable, or get inflamed or infected.

What Causes Multiple Pilar Cysts On The Scalp to Form in the First Place?

The root cause is a genetic change in the way hair follicle cells behave. Normally, cells in the outer root sheath of a hair follicle die and shed as part of the hair growth cycle. In people who develop multiple pilar cysts, these cells instead keep producing keratin inside a closed sac under the skin.

This pattern is inherited in an autosomal dominant way. That means if one parent carries the gene mutation, each child has a 50 percent chance of developing multiple cysts. The condition often runs in families. If you have multiple cysts, there is a good chance a parent, sibling, or child also has them or will develop them.

Research published in dermatology journals has identified mutations in the KRT17 gene as a cause in some families. This gene provides instructions for making keratin 17, a protein in hair follicles. When the gene is faulty, the follicle cells do not shed properly and form cysts instead. Not all cases are linked to this gene, and researchers are still studying other possible genetic causes.

Does Having Multiple Pilar Cysts Mean I Have a Genetic Condition?

Yes, in most cases having multiple pilar cysts on the scalp points to an inherited tendency. A single cyst can happen by chance. But two or more, especially if they appear over time, strongly suggest a genetic pattern.

The most common genetic condition linked to multiple pilar cysts is steatocystoma multiplex. Despite the name, the cysts in this condition are pilar cysts, not oil gland cysts. People with steatocystoma multiplex develop dozens or even hundreds of small cysts on the scalp, chest, arms, and upper body. The cysts usually start appearing in the teenage years or early twenties.

Another related condition is familial pilar cyst syndrome. In this case, the cysts are mostly on the scalp and tend to be fewer in number but larger in size. Both conditions are benign and do not affect overall health. But they can be a cosmetic concern and sometimes cause discomfort if cysts become inflamed or infected.

What Does Research Show About How These Cysts Develop Over Time?

Studies have found that pilar cysts grow slowly over months or years. They do not appear all at once. A person might notice one cyst in their twenties, then another in their thirties, and more later in life. The number and size can increase with age.

Hormonal changes may play a role. Some people report that cysts become more noticeable or tender during times of hormonal fluctuation, such as pregnancy or menopause. However, strong clinical evidence for this link is limited. The connection is mostly based on patient reports rather than controlled studies.

Inflammation can change how a cyst behaves. If a cyst gets irritated or infected, it can become red, swollen, and painful. This is called an inflamed cyst. It may rupture under the skin, which causes more inflammation and can lead to scarring. Repeated inflammation can make cysts harder to remove later.

One non-obvious point: pilar cysts have a thick, tough wall compared to other cyst types. This makes them easier for a doctor to remove whole. When a cyst is removed intact, it is less likely to come back in the same spot.

What Are the Best Treatment Options and What Actually Works?

Treatment depends on whether the cysts bother you. If they are small and not causing symptoms, you do not need to do anything. Many people live with them for years without issue. No topical cream or medication has been shown to make pilar cysts shrink or disappear.

The only definitive treatment is surgical removal. A dermatologist makes a small incision, removes the cyst wall intact, and closes the wound. This is usually done under local anesthesia in an office visit. The recovery is quick, and scarring is minimal if done properly.

For inflamed cysts, doctors may first treat the infection with antibiotics or drain the cyst to relieve pressure. But draining alone is not a cure. The cyst wall remains under the skin, so the cyst will fill back up with keratin. Only removal of the entire wall prevents recurrence.

Some people try home remedies like warm compresses or tea tree oil. These may reduce inflammation temporarily but will not remove the cyst. There is no evidence that any natural remedy can dissolve a pilar cyst.

What Should You Avoid If You Have Multiple Pilar Cysts?

Do not try to pop or squeeze a pilar cyst at home. The wall is thick and the contents are firm. Squeezing can rupture the cyst under the skin, causing severe inflammation, infection, and scarring. It also makes later removal more difficult for a surgeon.

Do not use sharp objects to cut or drain a cyst yourself. This introduces bacteria and can lead to cellulitis, a skin infection that requires oral antibiotics. In rare cases, it can lead to a deeper infection like an abscess that needs drainage.

Do not assume a lump is a cyst without a doctor’s confirmation. Other scalp lumps can look similar, including lipomas, sebaceous adenomas, and rarely, skin cancers. A dermatologist can usually tell the difference by feel and appearance. If there is any doubt, they may do a biopsy.

Avoid heavy hair products or tight hairstyles that pull on the scalp. These can irritate existing cysts and make them more likely to become inflamed. Gentle hair care is best.

Do Multiple Pilar Cysts Increase the Risk of Cancer?

No. Pilar cysts are benign growths. They do not turn into cancer. The risk of malignancy is extremely low, and most dermatologists consider it negligible.

There is a rare condition called proliferating pilar tumor, where a pilar cyst grows rapidly and becomes large. This is still benign in most cases, though it can look concerning under a microscope. True malignant transformation is exceptionally rare and has only been documented in a handful of case reports worldwide.

However, any new lump on the scalp that grows quickly, changes color, or becomes painful should be checked by a doctor. These features are not typical of pilar cysts and may indicate something else. The CDC recommends that any skin growth that changes in size, shape, or color within a few weeks be evaluated.

Can You Prevent Multiple Pilar Cysts From Forming?

There is no known way to prevent pilar cysts. Because they are driven by genetics, you cannot stop them from forming through diet, lifestyle, or skin care. No supplement, vitamin, or topical product has been shown to prevent their development.

What you can do is manage them. If you know you have the genetic tendency, you can monitor your scalp for new cysts and have them removed early if they bother you. Early removal when cysts are small leaves smaller scars.

Some people ask about laser treatment or other non-surgical methods. As of 2026, there is no clinical evidence that lasers, freezing, or chemical peels effectively remove pilar cysts. Surgical excision remains the only proven method.