Painful Thigh Lump: Causes

Skin abscess

A skin abscess is a large pocket of pus that has formed just beneath the skin. It is caused by bacteria getting under the skin, usually through a small cut or scratch, and beginning to multiply. The body fights the invasion with white blood cells, which kill some of the infected tissue but form pus within the cavity that remains.

Symptoms include a large, red, swollen, painful lump of pus anywhere on the body beneath the skin. There may be fever, chills, and body aches from the infection.

If not treated, there is the risk of an abscess enlarging, spreading, and causing serious illness.

Diagnosis is made through physical examination.

A small abscess may heal on its own, through the body's immune system. But some will need to be drained or lanced in a medical provider's office so that the pus can be cleaned out. Antibiotics are usually prescribed.

Keeping the skin clean, and using only clean clothes and towels, will help to make sure that the abscess does not recur.

Rarity: Common

Top Symptoms: rash with bumps or blisters, red rash, red skin bump larger than 1/2 cm in diameter, pus-filled rash, rash

Symptoms that always occur with skin abscess: rash with bumps or blisters

Urgency: Primary care doctor

Skin cyst

A cyst is a small sac or lump, filled with fluid, air, fat, or other material, that begins to grow somewhere in the body for no apparent reason. A skin cyst is one that forms just beneath the skin.

It's believed that skin cysts form around trapped keratin cells – the cells that form the relatively tough outer layer of the skin.

These cysts are not contagious.

Anyone can get a skin cyst, but they are most common in those who are over age 18, have acne, or have injured the skin.

Symptoms include the appearance of a small, rounded lump under the skin. Cysts are normally painless unless infected, when they will be reddened and sore and contain pus.

Diagnosis is made through physical examination. A small cyst can be left alone, though if it is unsightly or large enough to interfere with movement it can be removed in a simple procedure done in a doctor's office. An infected cyst must be treated so that the infection does not spread.

Rarity: Common

Top Symptoms: skin-colored armpit bump, marble sized armpit lump, small armpit lump

Symptoms that always occur with skin cyst: skin-colored armpit bump

Urgency: Wait and watch

Severe skin abscess

A skin abscess is an infection of the deeper skin that's typically due to bacteria seen on the skin. Recently, infections are more frequently caused by Staph. Aureus (puts the "staph" in "staph infections"). If the infection begins to spread, urgent treatment is required.

You should head to the nearest ER by car since your infection seems like it might be spreading. It is likely that you will be prescribed antibiotics. Surgery may be required to get rid of the whole abscess after the inflammation has died down. Do not drain the abscess yourself.

Rarity: Rare

Top Symptoms: fatigue, fever, painful neck lump, marble-size neck lump, pink or red neck bump

Symptoms that always occur with severe skin abscess: pink or red neck bump, red bump

Urgency: Hospital emergency room

Lipoma

Lipoma is a word that translates as "fatty tumor," but a lipoma is not cancer. It is simply a growth of fat between the muscle layer and the skin above it.

The exact cause is not known. The condition does run in families and is associated with other unusual syndromes such as adiposis dolorosa, which is similar. Lipomas most often appear after age 40.

Symptoms include a soft, easily moveable lump beneath the skin, about two inches across. A lipoma is painless unless its growth is irritating the nerves around it. They are most often found on the back, neck, and abdomen, and sometimes the arms and upper legs.

It is a good idea to have any new or unusual growth checked by a medical provider, just to make certain it is benign.

Diagnosis is made through physical examination, biopsy, and imaging such as ultrasound or CT scan.

Most of the time, treatment is not necessary unless the lipoma is unsightly or is interfering with other structures. It can be removed through surgery or liposuction.

Rarity: Uncommon

Top Symptoms: skin-colored groin bump, marble sized groin lump, small groin lump

Symptoms that always occur with lipoma: skin-colored groin bump

Urgency: Wait and watch

Enlarged lymph nodes in the groin

Enlarged lymph nodes occur when the node becomes larger as it fills with inflammatory cells. This often is a result of an infection but can occur without a known cause.

You should discuss with a health care provider whether or not your lymph node needs to be checked. Enlarged lymph nodes will usually shrink on their own. To speed up the process, try applying a warm, wet compress to the affected area.

Rarity: Common

Top Symptoms: groin lump, movable groin lump

Symptoms that always occur with enlarged lymph nodes in the groin: groin lump

Symptoms that never occur with enlarged lymph nodes in the groin: fever, unintentional weight loss, hard groin lump

Urgency: Phone call or in-person visit

Dermatofibroma

A dermatofibroma is a fairly common skin growth that usually appears on the lower legs, but may appear anywhere on the body. These mole-like growths are benign (noncancerous.)

The cause is not known, though a dermatofibroma may appear after a minor injury. The growths are not contagious.

Dermatofibromas are most common in adults and are rarely found in children.

Symptoms include a hard, raised growth that is red, pink, or brown and less than half an inch across. They are usually painless but may be tender or itchy, and may appear alone or in groups.

Any new growth on the skin should be seen by a medical provider, especially if the growth is very dark in color or changes its shape or appearance quickly.

Diagnosis is made through physical examination and sometimes biopsy.

A dermatofibroma does not require treatment unless it is interfering with clothing or is unsightly. They can be surgically removed, though this will leave a scar and the growth may eventually return.

Medical treatments for a painful thigh lump

If you do not find relief with the measures above and your thigh lump has not resolved, consult your physician. They may recommend the following measures.

• Incision and drainage: If your thigh lump is caused by an infection that has caused a collection of pus under your skin, a medical professional may need to cut a small hole (incision) in the skin overlying the bump in order to drain the pus collection.
• Antibiotics: You may also be prescribed an antibiotic in a pill or cream/ointment form in order to fight the infection if your thigh lump is due to a bacterial or fungal cause.
• Surgery: If your thigh lump is caused by an abnormal growth of cells, your doctor may recommend surgery to remove the lump, assess what kind of cells are causing it, and determine whether the lump is cancerous or not.

When a painful thigh lump is an emergency

Seek immediate medical attention in the emergency room or call 911 for the following:

• Severe or worsening pain and/or swelling
• Redness that is worsening or spreading around the lump
• Fever
• Sudden loss of sensation

Why is my thigh lump painful?

The pain you're feeling depends on the cause of the thigh lump. Thigh lumps caused by infection may be painful because the body's immune response is reacting to the infection, and you feel pain because your body is alerting you that something is wrong. If it does not resolve soon, you should seek medical attention.

Why is my pain still persisting after my injury?

If your thigh lump is due to trauma, the pain you're feeling is most likely the aftermath of the damage caused to the area in and around the lump. If your pain doesn't get any better or gets worse, seek the attention of a medical provider.

Will my thigh lump go away on its own?

It depends. If your lump is due to abnormal cell growth, it might stay the same, grow or shrink. If it is caused by infection, it might go away on its own as your body fights it, or it might go away with some over-the-counter anti-inflammatory medication like Advil or Motrin.

Do thigh abscesses ever resolve on their own?

If the infection has caused a collection of pus (an abscess) to form, it might go away, but typically this requires draining by a medical professional. Any lump that persists or grows over time should be seen by a medical provider.

Why is my thigh lump growing?

Your thigh lump may be growing due to fluid collecting in and around the area of the lump. If your thigh lump is due to trauma, you can often experience swelling around the injured area, but this swelling should decrease over time. A thigh lump due to infection may grow as pus collects in the lump under the skin or as lymph nodes enlarge in reaction to the infection. A lump can also grow if abnormal cells are building up, and these cells can either be cancerous or non-cancerous. A thigh lump that is growing rapidly in size or persistently grows should be medically evaluated.

Questions your doctor may ask about painful thigh lump

• What color is the bump?
• Any fever today or during the last week?
• Do you have a rash?
• Is there something coming out of the bump?

Self-diagnose with our free Buoy Assistant if you answer yes on any of these questions.