Causes of Skin Boils with Pictures

Pictures of MRSA and Other Infections

Skin boils are infections caused by bacteria or fungi. They commonly develop as a lump around a hair follicle or oil gland. Looking at pictures of boils and understanding the conditions that cause them can help you recognize them if they appear on your body. This can help guide you in seeking treatment.

Boils can show up in odd places. They can show up anywhere on your body, including your pubic area. This article explains boil symptoms using pictures of skin boils from MRSA and other infections. It also describes the differences between boils and similar skin conditions and the conditions that result in boils.

Boil Symptoms

Skin boils are often caused by an infection with Staphylococcus bacteria. They may also develop from other infectious agents, like group A Streptococcus.

Skin boils can have a pinkish, red, or whitish-yellow color on lighter skin tones and a purplish, brown, or black color on darker skin tones.

Symptoms include:

  • Swelling
  • Oozing of pus or clear fluid
  • Pain

Boil vs. Pimple

Unlike boils, pimples aren't caused by an infection. Instead, they are caused by blocked pores. This blockage causes pimples, blackheads, and whiteheads to form a bump on the skin. Pimples are the main symptom of acne, a common skin condition.

Sometimes, with acne, bacteria can infect clogged pores, leading to inflammation and redness or darkening of the skin. This type of acne is known as inflammatory acne.

Many people also misidentify a boil for a bug or spider bite. Unless you catch a spider in the act of biting, an infection likely is what's causing a boil.

1

MRSA Blister

This photo contains content that some people may find graphic or disturbing.

MRSA blister

Gregory Moran, MD. / Centers for Disease Control and Prevention

A blister caused by methicillin-resistant Staphylococcus aureus (MRSA) infection is also called a staph infection. But even though it's common for MRSA to show up as blisters or boils, not all blisters or boils are from MRSA.

Other forms of MRSA and group A Streptococcus bacteria cause skin infections that look very similar.

MRSA can spread by touching someone's skin colonized with MRSA or touching contaminated surfaces.

Symptoms

MRSA can colonize (live) on the skin and cause no harm. However, when you have a cut or scrape, the bacterium can enter the body and cause infection. When this occurs, symptoms may include:

  • Pain
  • Swelling
  • Redness
  • Fever

Healthcare providers may suspect MRSA if you're showing these symptoms, but will need to test for MRSA before they can make a diagnosis.

MRSA blisters commonly form on areas covered by hair, such as the back of the neck, groin, buttocks, armpit, and beard areas.

Signs of a deeper, more dangerous infection include an area that keeps growing, a raised center that oozes pus, increasing tenderness, and fatigue.

See a healthcare provider if your boil is not healing on its own or the infection is spreading. The earlier you get medical care, the better. It's less likely the infection will get serious when you get treatment as early as possible.

Treatment

Due to this bacterium's resistance to many standard antibiotics, treating this infection requires specific types of medication and dosages. Usually, treatment involves a seven- to 10-day course of oral antibiotics such as:

  • Trimethoprim-sulfamethoxazole
  • Clindamycin
  • Minocycline
  • Linezolid
  • Doxycycline

Cutting an MRSA boil open to drain it should only be done by a healthcare professional using a sterile technique to avoid spreading the MRSA or introducing another infection.

Always take the full course of antibiotics. If you don't take antibiotics for as many days as your healthcare provider prescribes, MRSA may not fully go away. Even if you start to feel better, you could still have MRSA and may develop symptoms again.

2

Cystic Acne

Women with cystic acne on the face

Sinenkiy / Getty Images

Cystic acne is the most severe type of acne. It causes acne cysts that form deep under the skin.

It occurs when pores become clogged with excess sebum (an oily substance found in glands) and dead skin cells. When bacteria infect these clogged pores, the immune system reacts to fight the threat. This reaction causes deep swelling in the skin's middle layer (the dermis).

Symptoms

An acne cyst is usually red or darker than your skin tone and may have a whitish-yellow head. A cyst can be crusty, painful, or tender to touch, and either large or small in size.

Since the face has an abundance of oil glands, acne cysts tend to appear there. However, they can also appear on the back, butt, chest, neck, shoulders, and upper arms.

Boils differ from cysts. Cysts are fluid-filled sacs that are typically noninfectious and noncontagious. However, cysts can become infected if bacteria get in broken skin. In addition, boils usually multiply and can be painful, while cysts typically grow slowly and aren't painful.

Treatment

Treating cystic acne typically includes taking oral antibiotics and applying certain topical gels or creams (often prescription-strength) to the affected area. Some treatments include the use of:

3

Impetigo

This photo contains content that some people may find graphic or disturbing.

Child with Impetigo on face

Dr. Ricardo Hoogstra / Hoogstra Medical Centers

Impetigo is a bacterial skin infection that is pretty common in kids (in fact, some incorrectly pronounce it infantigo). It comes from either Staphylococcus or Streptococcus bacteria.

Impetigo is highly contagious and spreads through contact with an infected person's sores or the fluid from these sores. It can also spread by sharing towels or clothing with an infected person.

Symptoms

Symptoms of impetigo typically occur within three days after infection. They can include:

  • Skin lesions on the lips, nose, arms, and legs
  • Pus-filled blisters that easily burst
  • Reddish skin with blisters that contain tan or yellowish fluid
  • Rash

Treatment

Impetigo is treatable and doesn't cause a fever. Healthcare providers will most likely be able to identify it just by looking at it. However, if they aren't sure, they may take a biopsy of the affected skin.

Treating impetigo typically involves applying prescribed topical antibiotics such as mupirocin. Oral antibiotics such as cephalosporins, clindamycin, and sulfamethoxazole may also be used.

4

Hidradenitis Suppurativa

This photo contains content that some people may find graphic or disturbing.

Hidradenitis Suppurativa lesions under armpits

Jere Mammino, DO / American Osteopathic College of Dermatology

Hidradenitis suppurativa, sometimes referred to as acne inversa, is a chronic skin disease that affects the sweat glands and hair follicles. This condition causes bumps on the skin that can turn into painful boils. After they heal, scarring occurs.

It's unknown why some people develop this condition. However, it's thought that sex hormones and lifestyle factors like smoking may play a role.

Experts believe that hidradenitis suppurativa occurs when an abnormal growth of cells clogs hair follicles. This debris buildup eventually causes the follicle to rupture, leading to inflammation and scarring. Inflammation is an immune system response to aid in the healing process.

Symptoms

Symptoms of hidradenitis suppurativa include:

  • Pain
  • Swelling
  • Pimple-like, pus-filled lesions
  • Scarring

The condition typically affects areas where skin touches skin, such as the underarms, groin, buttocks, and breasts.

Treatment

For mild cases, treatment usually involves taking anti-inflammatory medications. In addition, applying topical cleansing agents, such as acne washes and antibacterial soaps, can help.

Treatment for more severe cases may include:

5

Stye

Man with a stye bump

Mariia Skovpen / Getty Images

A stye (hordeolum) is a painful, red bump that develops on the eyelid. On darker skin tones, the redness may be more difficult to see.

Styes are usually caused by a blockage of oil-producing glands in the eyelash follicle and Staphylococcus bacterial infection.

A stye can form either on the outer or inner eyelid. A stye isn't usually contagious, but it can release small amounts of bacteria. This bacteria can spread through physical touch or contact with items such as pillows.

Symptoms

Symptoms of a stye can include:

  • Eyelid crusting
  • Teary or scratchy eyes
  • A painful swelling on the eyelid
  • Light sensitivity

Treatment

Styes typically clear without medical treatment in one to two weeks. Self-care methods may speed healing. A common way to clear a stye is to place warm compresses on the eyelid for 10 to 15 minutes at a time, three to five times a day.

Seeing an ophthalmologist may be wise if your stye doesn't improve with at-home care. An ophthalmologist may prescribe topical or oral antibiotics and ensure there's no underlying problem. Also, a healthcare provider may surgically drain a stye if it blocks vision or does not clear with antibiotics.

6

Carbuncle

This photo contains content that some people may find graphic or disturbing.

Carbuncle on a leg of a women

Katherine Humphries / StatPearls: Carbuncle

A single boil is called a furuncle. A carbuncle is a cluster of boils that form on a particular body area. Like a boil, a carbuncle results from a bacterial infection, usually by Staphylococcus aureus.

Research reveals that carbuncles are commonly associated with diabetes.

Symptoms

Because a carbuncle affects deeper layers under the skin, symptoms are more severe than a single boil.

Typically, the affected area is red or darker than your normal skin tone and inflamed with multiple pus-filled boils. Carbuncles can develop anywhere on the body, but they commonly occur on the back and neck. A carbuncle may also include symptoms like:

  • Pus-filled boils
  • Fever
  • Fatigue
  • Pain

Treatment

Although warm compresses may help it drain, it's not uncommon for a carbuncle to need to be surgically drained by a healthcare provider. A healthcare provider may also prescribe antibiotics like trimethoprim-sulfamethoxazole and doxycycline, especially if it returns.

Genital Herpes

Sexually transmitted infections (STIs, formerly sexually transmitted diseases, or STDs) may cause boil-like lesions. Genital herpes can cause blisters and ulcers on or around the genitals or rectum. The blisters themselves are small, but they can form larger clusters.

Complications of Boils

Without treatment, a boil may take one to three weeks to heal. However, with treatment, boils may clear much faster.

If it's not healing on it's own, the infection could get worse and potentially get into the bloodstream. From there, it could spread to a heart valve, bone, joint, or the lungs. It could also colonize implanted medical devices like an intravenous (IV) line, pacemaker, or replacement joint.

For severe infections, hospitalization and IV antibiotic treatment may be needed.

Preventing Boils

Practicing proper hygiene can help prevent boils. Here are tips for practicing good hygiene:

  • Wash your hands frequently using soap and water, rubbing your hands together for 15 to 30 seconds. Make sure to get your fingernails, between your fingers, and your wrists.
  • Use alcohol-based hand sanitizers if a sink is not available.
  • Keep cuts and scrapes clean and dry. Cover them with a bandage until healed.
  • Avoid touching other people's wounds or bandages.
  • Avoid sharing personal items, including washcloths, razors, clothing, brushes, combs, and makeup.

When to See a Healthcare Provider

Skin boils usually heal on their own, especially with proper self-boil treatment. However, some things may indicate an infection is brewing. If you notice any of the following symptoms, contact a healthcare provider:

  • Fever
  • Boils that last longer than one week
  • Multiple boils or carbuncles
  • Boils that return

A healthcare provider can give proper treatment and ensure there isn't an underlying problem.

See a healthcare provider if you develop a boil and have diabetes or a condition that affects the immune system.

Summary

Many things may cause boils, including MRSA, cystic acne, impetigo, hidradenitis suppurativa, styes, and carbuncles. Symptoms vary depending on the condition but usually include sensitive pus-filled lesions.

These pictures of boils caused by MRSA and other infections illustrate visible symptoms like discoloration, swelling, and pus formation. However, some people may have fever as well.

Treatment varies depending on the cause. If you have any signs of infection or the boil isn't responding to at-home treatment, contact a healthcare provider get checked out and tested. The earlier you get treatment, the less likely you are to develop a serious infection.

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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Rod Brouhard, EMT-P
Rod Brouhard is an emergency medical technician paramedic (EMT-P), journalist, educator, and advocate for emergency medical service providers and patients.