Ingrown Hair Cyst: Symptoms, Causes, Treatment and When to See a Doctor

An ingrown hair cyst can develop when a hair curls back into the skin and triggers inflammation around the follicle, creating a deeper lump rather than the small bump typically associated with an ordinary ingrown hair.

The area can be itchy, tender, swollen, discolored, or painful, especially if an infected ingrown hair develops. Shaving, waxing, tweezing, and closely removing hair can increase the risk, particularly for people with coarse or curly hair.

Most uncomplicated cases improve with gentle skin care and avoiding further irritation, but persistent, enlarging, or pus-filled lumps may require professional treatment. Knowing when an ingrown hair needs medical attention can also help prevent scarring and complications.

Key Takeaways

• An ingrown hair cyst develops when a trapped hair causes a deeper inflammatory response around the follicle.

• Shaving, waxing, and tweezing can increase the risk, especially with coarse or curly hair.

• A painful, enlarging, or pus-filled lump may indicate infection.

• Squeezing or puncturing the cyst can increase the risk of infection and scarring.

• Persistent, recurrent, or infected cysts may require treatment from a healthcare professional.

What Is an Ingrown Hair Cyst?

An ingrown hair cyst is a fluid-filled or skin-cell-filled sac that develops around an ingrown hair beneath the surface of the skin. When a hair curls back into the skin rather than growing outward, the body can respond to it as a foreign substance. Fluid, skin cells and other material may accumulate around the follicle, creating a deeper lump.

An ordinary ingrown hair usually appears as a small raised bump, while a cyst can become larger and sit deeper under the skin. It may be firm or soft and can occur anywhere hair is removed, including the face, neck, legs, underarms, chest, back and pubic area.

Ingrown Hair Cyst Symptoms

Ingrown hair cyst symptoms can include a raised lump beneath the skin, redness or discoloration, itching, tenderness, swelling, and a hair that is trapped beneath the skin. An ingrown hair under the skin may initially resemble a pimple or razor bump, but the area can become more noticeable as inflammation develops.

Common symptoms include:

• A raised ingrown hair lump beneath the skin

• Red, brown, purple, or otherwise discolored skin

• Itching or irritation

• Burning, stinging, or tenderness

• Swelling around the hair follicle

• A visible hair trapped beneath the skin

• A firm or soft bump that gradually becomes larger

• Pus or other drainage if the area becomes infected

A painful ingrown hair does not necessarily mean that an infection is present. However, increasing pain, warmth, swelling, redness that spreads beyond the affected area, or pus-like drainage can indicate an infection and may require medical evaluation.

What Causes an Ingrown Hair Cyst?

The primary cause is a hair that grows back into the skin rather than outward through the follicle. Hair removal techniques can make this more likely because they alter the hair shaft and leave the follicle in place for the new hair to grow from.

Shaving against the direction of hair growth and stretching the skin while shaving can also increase the likelihood of ingrown hairs.

Infected Ingrown Hair: What Are the Signs?

An infected ingrown hair occurs when bacteria enter an irritated or damaged follicle. Infection may develop after scratching, squeezing, or repeatedly manipulating the area, although not every infected-looking bump is caused by an ingrown hair.

Signs that an ingrown hair infection may be developing include:

• Increasing pain or tenderness

• Worsening redness or swelling

• Skin that feels noticeably warm

• Pus or other fluid draining from the bump

• A lump that continues to enlarge

• Fever accompanying local symptoms

An infected cyst may require medical treatment, including antibiotics or a procedure to drain or remove the cyst, depending on its severity.

Ingrown Hair Cyst Treatment

Ingrown hair cyst treatment depends on its size, symptoms and whether infection is present. Small, uncomplicated cysts may resolve as the inflammation settles, while persistent or infected lesions may require treatment by a healthcare professional.

For mild cases, appropriate care may include:

• Stopping shaving, waxing or tweezing the affected area until it heals

• Applying a warm compress to ease discomfort

• Keeping the skin clean and avoiding unnecessary friction

• Avoiding picking, squeezing or puncturing the lump

A doctor may recommend topical medications to reduce inflammation or improve skin-cell turnover. If bacterial infection is present, antibiotic treatment may be appropriate. Larger or persistent cysts may need professional drainage or removal.

How to Remove an Ingrown Hair Cyst Safely

The safest way to remove an ingrown hair cyst is to have a healthcare professional assess it and, when necessary, treat it rather than trying to remove it at home. Squeezing the cyst, piercing it with a needle, or cutting into it can damage surrounding tissue and increase the risk of infection, inflammation, and scarring.

A healthcare professional can determine whether the lump is actually an ingrown hair cyst or another type of skin lesion. If treatment is needed, a healthcare professional can remove or drain the cyst or trapped hair using appropriate sterile technique. 

The recommended approach depends on the size, location, inflammation, and whether an infection is present.

How to Prevent Ingrown Hair Cysts

Prevention focuses primarily on reducing irritation during hair removal and giving the skin time to recover. People who frequently develop ingrown hairs may benefit from changing their shaving technique or considering an alternative method of hair removal.

Helpful measures include:

• Wetting the skin and hair with warm water before shaving

• Using shaving cream or gel

• Shaving in the direction of hair growth

• Avoiding an excessively close shave

• Using a clean, sharp razor or an electric trimmer

• Avoiding repeated passes over the same area

• Gently exfoliating and moisturizing the skin when appropriate

For people with persistent problems, a dermatologist may discuss longer-term options such as laser hair removal or electrolysis.

When to See a Doctor for an Ingrown Hair Cyst

You should see a healthcare professional for an ingrown hair cyst when the lump persists, becomes increasingly painful or inflamed, repeatedly returns, or develops signs of infection. Most isolated ingrown hairs are not serious and may resolve on their own, but a persistent or worsening lump may need medical evaluation.

You should contact a healthcare professional if:

• The lump continues to grow or does not improve

• Pain, redness, warmth, or swelling is getting worse

• Pus or other drainage develops

• You develop a fever or feel generally unwell

• The problem keeps recurring despite changes in hair-removal habits

• The lump is unusually large, painful, or difficult to manage

• You are unsure whether the lump is actually an ingrown hair cyst

A healthcare professional can examine the lesion and determine whether it is an ingrown hair or another skin condition that may look similar, such as folliculitis, an epidermoid cyst, or another type of skin lesion. This assessment can help determine whether treatment or further evaluation is needed.

Frequently Asked Questions

How long does an ingrown hair cyst last?

Healing time varies depending on the size of the cyst, the degree of inflammation, and whether an infection is present. Some resolve within days, while others can persist for several weeks.

Is a deep ingrown hair the same as an ingrown hair cyst?

Not necessarily. A deep ingrown hair may remain beneath the skin and cause a noticeable lump, but a cyst involves a sac that develops around the trapped hair. A healthcare professional can distinguish between the two during an examination.

Can ingrown hair cysts leave scars?

They can. Inflammation, infection and attempts to squeeze or manipulate the lesion can contribute to scarring or changes in skin pigmentation.