Causes of Skin Boils with Pictures

Pictures of Skin Boils from 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.

This article explains boil symptoms, how boils differ from similar skin conditions, and 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 with symptoms that include:

  • Swelling
  • Oozing of pus or clear fluid
  • Pain

Boil vs. Pimple

Skin boils and pimples can look similar, but there are differences. For example, 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 redness and inflammation. This type of acne is known as inflammatory acne.

Boil vs. Cyst

Boils also differ from cysts, which are fluid-filled sacs that are typically non-infectious and non-contagious. 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.

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.


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 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

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

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


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

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.


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).


An acne cyst is usually red 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.


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:



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 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


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.


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.

The reason some people develop this condition is unknown. However, it's thought that sex hormones and lifestyle factors like smoking may play roles.

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 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.


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:



Man with a stye bump

Mariia Skovpen / Getty Images

A stye (hordeolum) is a painful, red bump that develops on the eyelid. It's 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 of a stye can include:

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


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. They 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.



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.


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

Typically, the affected area is red 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


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.

When to See a Doctor

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, 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.


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.

Treatment varies depending on the cause. If you have any signs of infection or the boil isn't responding to at-home treatment, you should contact a healthcare provider.

Frequently Asked Questions

  • What is the best antibiotic for skin boils?

    There isn't a clear-cut best antibiotic for skin boils. Some antibiotics may work better than others in clearing a particular bacterium that causes a skin boil. For example, trimethoprim-sulfamethoxazole, clindamycin, and minocycline are more successful in treating an MRSA infection. But skin boils caused by non-MRSA conditions can usually be treated with antibiotics like amoxicillin, cephalosporins, and dicloxacillin.

  • How do you prevent boils?

    Practicing proper hygiene can help prevent boils. For example, washing your hands frequently and bathing regularly can help prevent the spread of bacteria. Also, try avoiding physical contact and sharing items like washcloths and towels with those who have a staph infection or boil, as the bacteria can spread through contact.

  • How long do boils last?

    Without treatment, a boil may take up to two weeks or more to heal. However, with treatment, boils may clear much faster.

22 Sources
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.