Finding a lump under your skin can be scary, whether you have hidradenitis suppurativa (HS) or not. It’s hard to know what you’re experiencing just by looking at your skin, and terms like “carbuncle” or “abscess” can be confusing. While you should always see a dermatologist for any skin changes, this guide can help you understand what you might be dealing with.

What’s an Abscess?

An abscess is a pus-filled pocket that forms under your skin, inside your mouth, or near your organs. When it’s on the skin, it usually starts as a tender, red, warm nodule that fills with pus over time. If the abscess bursts, pus (and sometimes blood) may leak out.

Abscesses can form for several reasons. It may be due to a bacterial infection (such as staphylococcus, also called a staph infection). Your body sees the bacteria as an invader and sends white blood cells to fight it. This can cause nearby tissue to die, creating a pocket that fills with pus.

Abscesses may also form due to hidradenitis suppurativa. HS is a chronic inflammatory condition that causes abscesses to form under the skin due to blocked hair follicles, often in areas where skin rubs together.

Common areas for abscesses include the skin around the breasts, the armpits, or the buttocks. These areas are also prone to bacterial skin infections, which can make it hard to tell the cause of your skin abscess. That’s why it’s important to get medical advice from a dermatologist or another healthcare professional for any abscesses.

What’s a Carbuncle?

A carbuncle is a cluster of boils filled with pus that affect your hair follicles. Boils (also called furuncles) may look similar to abscesses at first, but they only affect the top layer of the skin. Like abscesses, they can be caused by bacterial infections, such as staph infection.

Abscesses are deeper and larger than boils. However, when boils join together to form a carbuncle, the infection goes deeper under the skin and becomes more painful, making it look similar to an abscess. People with a carbuncle or abscess may feel tired and develop a fever.

Abscesses and Carbuncles: The Key Difference

While carbuncles and abscesses have many similarities, one key difference is that a carbuncle often has multiple pustules (which look like pimple heads) on it. An abscess usually has only one head.

Treatment Options

Your dermatology provider or another healthcare professional will recommend the best treatment for you depending on your skin condition. Below are some general guidelines.

How Are Abscesses Treated?

Minor abscesses may go away on their own. If not, home remedies such as applying warm compresses can help the pus drain and speed up healing. If the abscess doesn’t go away, a doctor may need to drain it. They may also prescribe oral antibiotics to clear the infection.

Don’t squeeze an abscess at home. This can spread bacteria to other parts of your body.

How Are Carbuncles Treated?

Carbuncles often heal without treatment in about two weeks. You can apply clean, warm, moist cloths (such as washcloths) to help the pus drain. If a carbuncle doesn’t go away, a doctor may perform a minor procedure to drain it. Your doctor might also recommend washing the carbuncle with over-the-counter or prescription antibacterial soap or prescribe topical or oral antibiotics.

As with abscesses, you should never try to cut or squeeze a carbuncle. This can make it worse or spread bacteria to other areas.

How Is HS Treated?

If you’re diagnosed with hidradenitis suppurativa, your dermatologist will work with you to create a treatment plan. For mild HS, they may prescribe topical antibiotics. For more severe cases, your doctor may instead recommend oral antibiotics, hormonal therapies, or biologics.

When To Call a Doctor

If you have a bump on your skin that doesn’t seem to be getting better, it’s best to contact your healthcare provider for advice.

When To See a Doctor About Abscesses

Call your dermatologist or doctor if your abscess:

• Is accompanied by a fever
• Becomes more painful
• Gets more red or swollen

When To See a Doctor About Carbuncles

Contact your healthcare provider right away if your carbuncle:

• Doesn’t improve with home remedies after two weeks
• Is on your face or the skin above your spine
• Keeps coming back
• Causes more pain
• Has a lot of swelling around it
• Has red streaks coming from its center
• Is accompanied by a fever

When To See a Doctor About Suspected HS

If you have abscesses, boils, or carbuncles that keep coming back, you may have HS. Reach out to a doctor to evaluate whether you’re experiencing HS symptoms, which can include painful lumps under your skin and lesions that rupture and leak discharge, which might smell.

HS often occurs in cycles, with flare-ups followed by periods when symptoms improve. A dermatologist can help diagnose HS and create a treatment plan.

Talk With Others Who Understand

At myHSteam, you’ll find the social network for people with hidradenitis suppurativa and their loved ones. On myHSteam, more than 46,000 members come together to ask questions, give advice, and share their stories with others who understand life with hidradenitis suppurativa.

Have you ever had trouble telling the difference between soft tissue infections on your skin, such as abscesses and carbuncles? How did you figure out what was affecting you? Share your experience in the comments below, or start a conversation by posting on your Activities page.