Reviewed on 11/14/2022

What Are Boils?

Elbow with Boils
Elbow with boils
  • A boil is a skin infection that starts in a hair follicle or oil gland. At first, the skin turns red in the area of the infection, and a tender lump develops. After 4-7 days, the lump starts turning white as pus collects under the skin. If the infection spreads to the deeper tissues of the skin, then it becomes an abscess or furuncle.
  • The most common places for boils to appear are on the face, neck, armpits, shoulders, and buttocks. If several boils appear in a group, this is a more serious type of infection called a carbuncle.
  • Inflammation of hair follicles is called folliculitis, which can develop into a boil. This is common in the pubic area, especially after shaving.
  • Hidradenitis suppurativa, also called acne inversa, is a skin condition characterized by lumps under the skin, which often resemble pimples, particularly in the armpits, groin, and buttocks. It looks like boils but is not the same condition.

What Causes Boils?

Boils are usually caused by a bacteria called Staphylococcus (staph). Some staph infections develop into abscesses and can become serious very quickly. This germ can be present on normal skin and enters the body through tiny breaks in the skin or by traveling down a hair to the follicle.

The tiny breaks in the skin may be caused by cuts, scrapes, shaving, ingrown hairs, insect bites, or even skin diseases or conditions.

What Are Risk Factors for Boils?

Certain health problems make people more susceptible to skin infections such as boils. Examples of risk factors for boils include:

  • Diabetes mellitus
  • Problems with the immune system
  • Poor nutrition
  • Poor hygiene
  • Exposure to harsh chemicals that irritate the skin
  • Infection with community-acquired methicillin-resistant S. aureus (CA-MRSA)
  • Intravenous drug use

Other risk factors for contracting boils include close contact with others who have active infected boils and exposure to whirlpool foot baths at nail salons.

What Are the Signs and Symptoms of Boils? Are Boils Contagious?

Symptoms of a boil are initially a hard, red, painful pus-filled bump usually less than an inch in size. Over the next few days, the lump becomes softer, larger, and more painful. Soon a pocket of pus forms on the top of the boil. Signs and symptoms of a more advanced infection include:

  • Red, painful, and swollen skin around the boil
  • More boils may appear around the original one
  • Fever
  • Swollen lymph nodes near the boil

An active skin boil is contagious because the bacteria that causes them is contagious. Until the boil is drained and has healed, it is contagious through skin-to-skin contact or sharing objects. Boils should be covered with a bandage to prevent spreading the infection to other people.

When Should Someone Seek Medical Care for a Boil?

You should seek medical care for a boil if:

  • You have a boil and start running a fever.
  • The skin around the boil turns red or red streaks appear.
  • The pain becomes severe.
  • The boil does not drain.
  • A second boil appears.
  • You have a heart murmur, diabetes, any problem with your immune system, or are taking medications that suppress the immune system (for example, corticosteroids or chemotherapy for cancer) and you develop a boil.

Boils usually do not require emergency attention. If you are in poor health and you develop high fever and chills along with the infection, a trip to a hospital's emergency department is needed.

What Specialists Treat Boils?

Boils may initially be diagnosed by a primary care provider (PCP), such as a family practitioner, an internist, or a child's pediatrician. You may see an emergency medicine specialist in a hospital's emergency department.

You may also be referred to a dermatologist, a specialist in skin disorders, or a general surgeon if the boil needs surgical drainage.

What Exams and Tests Do Physicians Use to Diagnose Boils?

Your doctor can make the diagnosis of a boil with a physical exam. A culture of the infection may be needed to determine the exact type of bacteria causing the infection and the most appropriate antibiotic. If you frequently get boils, your doctor may want to do a blood test to see if you have diabetes or some other underlying cause.

Are There Home Remedies for Boils?

Home therapies should only be used on small boils. If your boil is bigger than a pea or has a lot of redness around it, seek medical attention rather than trying to deal with it yourself.

  • Apply warm compresses, and soak the boil in warm water. This will decrease the pain and help draw the pus to the surface so the boil can rupture. Once the boil comes to a head, it will burst with repeated soakings. This usually occurs within 5-7 days of its appearance. You can make a warm compress by soaking a washcloth in warm water and squeezing out the excess moisture.
  • When the boil starts draining, wash it with soap until all the pus is gone. Apply a clean and dry bandage. Continue to wash the infected area 2-3 times a day and use warm compresses until the wound heals.
  • Do not pop the boil with a needle. This may result in making the infection worse.

What Treatments Get Rid of Boils?

If the boil is large, your health care provider may need to open it up and drain the pus, called an incision and drainage (I&D) procedure. This is done with a scalpel after the area of the boil is numbed with a local anesthetic.

If the infection is deep, your doctor may put some gauze in the incision to keep it open and draining. The gauze is usually removed in two days.

If there are concerns about the seriousness of the infection, blood tests may be needed. The doctor may prescribe antibiotics if the infection is severe, such as:

A large skin abscess caused by a staph infection may need to be surgically opened and drained and treated with intravenous antibiotics.

Is Follow-up Necessary After Treating a Boil?

Whether the boil is drained at home or is lanced by a doctor, you will need to clean the infected area 2-3 times a day until the wound is healed. Apply petrolatum after washing and cover with a bandage. If the area turns red or looks as if it is getting infected again, contact your doctor.

Is It Possible to Prevent Boils?

You can prevent boils by following these guidelines:

  • Carefully wash the clothes, bed linens, and towels of a family member who is infected with boils.
  • Clean and treat minor skin wounds.
  • Practice good personal hygiene.
  • Stay as healthy as possible.

What Is the Prognosis of a Boil?

The prognosis for boils is usually very good. Most boils can be successfully treated if prompt care is taken. However, scarring may be a complication after a particularly large boil heals. In rare cases, complications of boils occur when the infection spreads.

Cellulitis, a secondary infection of the deeper layers of the skin, may occur.

Other less common secondary infections may include:

Staph is the cause of most boils.

Causes of Boils


Staphylococcus bacteria (also termed staph) are responsible for a number of common infections.

Sometimes the infections are relatively limited (such as a sty, boil, furuncle, or carbuncle), but other times they may spread to other skin areas (causing cellulitis, folliculitis, or impetigo). Unfortunately, these bacteria can reach the bloodstream (bacteremia) and end up in many different body sites, causing infections (wound infections, abscesses, osteomyelitis, endocarditis, pneumonia) that may cause severe harm or even be fatal.

Reviewed on 11/14/2022
American Academy of Dermatology. "Hidradenitis suppurativa." <>.

Baddour, Larry M. "Skin abscesses, furuncles, and carbuncles." Sept. 2016. <>.

United Kingdom. NHS. "Boils and Carbuncles -- Complications." Jan. 30, 2015. <>.