What Is Staph Infection? Symptoms, Causes, Diagnosis, Treatment, and Prevention

Staph infections are caused by a type of bacteria called staphylococcus. These germs can live on your skin, in your mouth, or in your nose.

There are more than 30 types of staph bacteria, but the most common is Staphylococcus aureus, according to MedlinePlus. (1) About 30 percent of healthy adults have S. aureus in their nose, and about 20 percent have it on their skin, notes the Merck Manual. (2)

Most of the time, staph doesn’t cause a problem. But if the bacteria spreads deeper into your body, you can develop a serious, or even life-threatening, infection.

Types of Staph Infections

There are two types of staph infections, broadly speaking: skin infections and invasive infections. Skin infections are much more common and, most of the time, less serious, although they can be annoying and painful. But they can develop into invasive infections if they’re left untreated. Invasive staph infections can be life-threatening if they’re not managed properly, notes the Mayo Clinic. (3)

Cellulitis, Impetigo, and Other Skin Infections Caused by Staph

Some examples of skin infections that can be caused by staph include:

Folliculitis In folliculitis, the hair follicles (the small pockets in the skin where strands of hair grow) become inflamed and often infected. Men with curly hair who shave their beard close to the skin often get folliculitis on the face and neck.

Stye A stye is a small, red, very painful bump that grows from the base of an eyelash or under the eyelid. There’s usually visible pus in the center of the bump.

Boils Boils are red, swollen, painful lumps that form under the skin. They usually start as an infected hair follicle that enlarges and fills with pus (bacteria, white blood cells, and dead skin). Boils, also called furuncles, often occur on the face, neck, armpits, buttocks, or inner thighs. A cluster of boils that form a connected area of infection is called a carbuncle.

Skin Abscess A skin abscess is a pocket of pus surrounded by a thick membrane under the skin. Abscesses form when the body tries to protect itself from an infection by walling it off. They can be treated by cutting a hole in the wall of the abscess with a surgical knife and draining the pus, or they can be drained by applying warm compresses. Smaller abscesses can be treated with antibiotics.

Cellulitis Cellulitis is an infection of the deeper layers of the skin, including the dermis, or second layer of skin, and the subcutaneous tissue, or fat and connective tissue that form the bottom layer of skin. Cellulitis can occur anywhere on the body but most commonly affects the lower legs.

Impetigo This common and highly contagious staph infection begins as small blisters, usually on the face, hands, or feet, that eventually develop a honey-colored crust. Impetigo usually affects young children, but anyone can develop it.

Staphylococcal Scalded Skin Syndrome This condition is caused by toxins produced by a staph infection and results in peeling skin over large areas of the body. The skin might look burned or scalded. It most often affects babies and young children.

Wound Infections These infections usually crop up two or more days after you’ve had a skin injury or surgery. (1,2,3)

Learn More About Cellulitis

Learn More About Impetigo

Invasive Staph Infections

Invasive staph infections happen when bacteria enter the bloodstream. Some types are:

Sepsis Sepsis is an infection of the bloodstream that leads to a widespread inflammatory response. It’s one of the most dangerous outcomes of staph and can spread throughout your body, affecting the function of internal organs.

Septic Arthritis This infection targets your joints, often the knees, hips, shoulders, finger joints, or toe joints.

Toxic Shock Syndrome This rare but serious condition can happen when staph bacteria get into your bloodstream and produce toxins. Toxic shock syndrome has been linked to the use of high-absorbency tampons, but anyone, including men, children, and women who don’t use tampons, can develop it under certain circumstances.

Endocarditis Endocarditis happens when bacteria affect areas in your heart, most typically the heart valves. If it’s not treated quickly, the infection can damage or destroy your heart valves.

Osteomyelitis This uncommon but serious condition happens when a bone in your body becomes infected.

Pyomyositis Pyomyositis is a rare bacterial infection of the skeletal muscles, which are the muscles you use for movement.

Pneumonia Pneumonia is a common infection that causes inflammation and fluid accumulation in the air sacs of your lungs, making it very hard to breathe comfortably.

Food Poisoning Food poisoning connected to staph is caused by eating foods contaminated by toxins that are produced by the bacteria. It is not a true bacterial infection and should not be treated with antibiotics. Foods typically becomes contaminated by being touched by people who have staph on their hands. (1,2,3)

Drug-Resistant Infections: MRSA

Methicillin-resistant Staphylococcus aureus (MRSA) is a type of staph infection that’s resistant to commonly used antibiotics, according to the American Academy of Family Physicians. (4)

Most cases of MRSA occur in people who’ve been in hospitals or other healthcare facilities. But so-called community-associated MRSA, in which the infection is spread outside of hospitals or healthcare facilities, also occurs.

Overuse and misuse of antibiotics are contributors to the development of MRSA. On an individual level, you can help prevent and control the spread of antibiotic resistance by taking antibiotics only when necessary (not for viral infections like the flu or colds) and when they are prescribed to you by a doctor.

Also, always finish your full course of antibiotics, even if your symptoms have improved, to prevent the development of antibiotic-resistant superbugs, such as MRSA.

Learn More About MRSA Symptoms, Diagnosis, and Treatment

Your symptoms of a staph infection will depend on what type of infection you have.

Skin infections typically cause redness, swelling, warmth, and pain — but all of those symptoms can range from mild to severe. Impetigo sores may or may not be painful, for example, while boils almost always are.

Some skin infections caused by staphylococcus, such as cellulitis or an infected wound, may cause a fever in addition to redness and pain at the site of the infection.

Invasive staph infections, such as sepsis (also called septicemia), endocarditis, and pneumonia, typically cause significant illness that may include fever, fast breathing or shortness of breath, fatigue, and sometimes confusion or disorientation.

Any time your breathing or heart function is affected by an illness — even if you don’t know what that illness is — you should seek medical attention quickly. (1,2,3)

Learn More About Signs and Symptoms of Staph Infection

Healthy people may carry staph bacteria and never know it, but when the skin is broken, the germs can enter the opening or wound and cause an infection.

Staph bacteria can also enter the body via urinary catheters, intravenous lines, or other implanted medical devices. The bacteria can additionally be present on tattoo needles that have not been properly cleaned and needles used to inject drugs, particularly if they are shared or reused.

Some staph infections of the skin are contagious and can pass from one person to another through skin-to-skin contact.

Staph bacteria can also survive on objects or surfaces, such as bedsheets, towels, or clothing. If an area of your skin is broken, touching contaminated items can be another way to get staph.

Infections are common in group living facilities, such as college dorms or prisons, where people are in close contact with one another. Warm, humid environments are also breeding grounds for staph.

Anyone can get a staph infection, but certain factors increase your odds.

You may have a higher risk of developing a staph infection if you have an underlying medical condition, such as:

• Diabetes
• Human immunodeficiency virus or acquired immunodeficiency syndrome
• Cancer
• Kidney failure
• A skin condition, such as eczema
• An open wound, burn, or sore
• A respiratory illness, such as cystic fibrosis or emphysema
• A weakened immune system

People who’ve had a recent surgery or have been hospitalized also have an increased risk of developing staph infection.

Taking certain medicines, including corticosteroids, insulin, or chemotherapy, can increase your chance of contracting staph. Additionally, staph infections are more common in individuals who inject drugs.

Sometimes staph bacteria spreads through medical tubing, such as dialysis tubes, urinary catheters, breathing tubes, feeding tubes, or intravascular catheters. You might have a greater chance of getting staph if you use certain devices that require tubing.

Playing a contact sport is another risk factor for staph. The bacteria can spread through skin-to-skin contact while playing or through touching equipment, towels, razors, or other items that are shared in the locker room. (3)

Household Spread of Drug-Resistant Staph

Recent research has shown that household environments play an important role in how staph infections, such as MRSA, are spread.

A study published in 2019 in The Lancet Infectious Diseases found that staph is more likely to spread from person to person in a residence that: (5)

• Has a lower cleanliness score (based on observations of odor, clutter, and grime)
• Is rented and crowded
• Houses people who share bedrooms, towels, or hygiene items
• Contains MRSA contamination on surfaces

Hygiene habits that reduced the risk of staph spread among household members include showering instead of taking baths, brushing teeth twice daily, and practicing frequent hand-washing.

To diagnose a staph infection, your doctor will examine any skin lesions you have and possibly take a skin or tissue sample or throat or nasal swab for a lab test to identify the cause of the infection.

In some cases, a doctor may order certain imaging tests if a deeper or internal infection is suspected. An echocardiogram, for example, can help your provider determine if the infection has affected your heart. (3)

When to See a Doctor About Staph

You should make an appointment with your doctor if you have:

• Any suspicious area of red or painful skin
• A high fever or fever accompanying skin symptoms
• Pus-filled blisters
• Two or more family members who have been diagnosed with a staph infection

You may want to put together a list of personal information and questions to bring to your doctor’s visit. Be sure to include the following items:

• A detailed account of your symptoms
• A record of any medical problems you have or have had in the past
• A description of your family’s medical history
• A list of all the medications and supplements you take
• Any questions you want to ask your doctor (3)

Prognosis of Staph Infection

The outlook for staph infections depends on the type of infection and how much it has spread in your body. Any underlying medical conditions may also influence how quickly you heal and recover.

Most superficial skin infections can be easily treated. But if you develop a serious infection that turns into sepsis, your prognosis is much worse. Some studies, such as one published in 2016 in The American Journal of Medicine, show that death rates from staph infection of the bloodstream range from 20 to 40 percent. (6)

The healing time for a staph infection depends on your age, your overall health, the type of infection you have, and what treatment you use. For instance, a boil can take 10 to 20 days to heal without treatment, but certain medicines may speed up the process, notes Kids Health. (7)

Antibiotics are the main line of treatment for most staph infections. The choice of antibiotic depends in part on how serious your infection is and what type of staph you have. Some minor skin infections will heal on their own with no drug treatment.

In addition to antibiotics, sometimes surgery is also needed to drain a wound, abscess, or boil.

Invasive staph infections usually require hospitalization for IV antibiotic treatment to fight the infection and other supportive treatment to help you heal. (1,2,3)

Medication Options

Antibiotics commonly used to treat staph infections include: (3)

• Cefazolin
• Nafcillin
• Oxacillin
• Vancomycin
• Daptomycin (Cubicin)
• Doxycylcine
• Sulfamethoxazole and trimethoprim (Bactrim)
• Clindamycin
• Linezolid (Zyvox)

Alternative and Complementary Therapies

Some people are interested in alternative therapies to treat their staph infections. Many internet claims tout applying natural substances, such as coconut oil, tea tree oil, apple cider vinegar, and essential oils, to the skin. But there’s limited if any research about the effectiveness of these products.

One natural remedy that has shown promise is manuka honey. This type of honey has demonstrated antimicrobial activity and the ability to enhance the effects of some antibiotics. Still, more research needs to be done before manuka honey can safely be used to treat staph, according to an article published in 2018 in Letters in Applied Microbiology. (8)

Always talk to your doctor before trying any type of alternative therapy.

Learn More About Treatment for Staph Infection: Medication, Alternative and Complementary Therapies, Surgery Options, and More

Prevention of Staph Infection

Staph bacteria are everywhere. You can’t avoid contact with them completely, but you can reduce your risk of developing an infection.

Some simple measures can help prevent the spread of staph.

Stay clean. Keeping your hands and body clean is the most important way to prevent a staph infection. Wash your hands frequently for at least 20 seconds at a time, and shower daily. If you don’t have soap handy for hand-washing, use a hand sanitizer that contains at least 60 percent alcohol.

Clean any wounds. Clean cuts, scrapes, and other injuries thoroughly with soap and water to rinse out dirt and bacteria.

Cover wounds. Put a bandage on any skin wounds until they heal completely.

Avoid sharing personal items. Don’t share towels, sheets, athletic equipment, or clothing with another person who might have a staph infection.

Change tampons frequently. If you use tampons, change them at least every four to eight hours to avoid developing toxic shock syndrome. Keeping tampons in for extended periods creates an environment that can cause bacteria to grow. It’s also a good idea to use the lowest absorbency tampon necessary to manage your menstrual flow.

Wash clothing and linens in hot water. If you or someone in your household has a staph infection, wash your clothes, towels, and bedding in hot water, using bleach, if possible. Dry the laundry in the dryer, making sure it is completely dry before you remove it.

Be careful about the food you eat. Wash your hands before preparing food or eating finger foods. Make sure that the hot foods you eat stay hot until you serve them, and the cold foods stay cold. The temperature of hot foods should be above 140 degrees F, and the temperature of cold foods should be below 40 degrees F. Don’t consume foods that don’t look or taste normal, or that may not have been stored safely. (3)

Use clean razors to shave. If you get a staph infection in an area you normally shave, avoid shaving until the infection clears. If you must shave, use a clean disposable razor. Don’t ever share razors with other people.

Wash yourself and your clothing after playing sports. Athletes should shower right after a game, competition, or practice. Also, wash your workout clothes and uniforms regularly, and keep your equipment clean. (1,3)

One of the most serious complications of a staph infection is when the bacteria invade the bloodstream and lead to sepsis, which is an inflammatory response caused by infections.

Sepsis can turn into septic shock, a life-threatening condition that causes your blood pressure to drop dramatically and additionally causes organ damage.

More than 1.7 million Americans are diagnosed with sepsis each year. In the United States, sepsis is the leading cause of death in hospitals. (9,10)

Sepsis is more common in very young children, older adults, and those with chronic diseases or weakened immune systems.

Learn More About Sepsis

Staph bacteria are one of the most common causes of skin infections in the United States.

About 33 percent of Americans are colonized with staph and about 1 percent with MRSA, according to the Centers for Disease Control and Prevention (CDC). (11) Most of these individuals won’t develop a serious infection.

Still, a CDC report released in March 2019 found that more than 119,000 people had a bloodstream staph infection in the United States in 2017, and nearly 20,000 died. (12)

The report also stated that while rates of MRSA bloodstream infections acquired in hospital settings declined by about 17 percent annually from 2005 to 2012, the rate of decline slowed from 2013 to 2016.

Meanwhile, the rate of community-onset MRSA declined by an average of 6.9 percent each year from 2005 to 2016.

The rate of hospital-onset methicillin-susceptible S. aureus (MSSA) infections did not change from 2012 to 2017, while community-acquired MSSA increased by nearly 4 percent per year during that period.

Staph Infection in Kids

Staph infections, including MRSA, can affect children and may be more common in those who spend time at daycare facilities and who play team sports, notes the University of Rochester. (13)

Children often pass staph bacteria through dirty hands or fingernails.

Talk to your child’s pediatrician if you think your child has a staph infection.

Staph Infection in Pets

Pets can develop a staph infection as a result of scratching, licking, or chewing their skin.

Sometimes staph bacteria can transfer from one animal to another, from a human to an animal, and in some cases, from an animal to a human.

Talk to your veterinarian if you think your pet might have an infection, notes PetMD. (14)

Anyone can develop a staph infection, but some research suggests that Black Americans in particular may be more susceptible to staph infections than people of other backgrounds.

A study published in JAMA found that Black Americans and people age 65 and older were among the most likely to contract a serious MRSA infection. (15)

The researchers theorized that Black people may be more susceptible to the infection than white people because they have higher rates of underlying medical conditions.

Other research, published in September 2018 in Clinical Infectious Diseases, found that racial disparities in healthcare-associated MRSA infections persisted from 2005 to 2014, even while the overall incidence of such infections decreased, with Black Americans having a 2 to 3 times higher incidence than white Americans. (16)

More studies need to be conducted to determine why MRSA affects difference races at different rates.

While staph is a common cause of infections of the skin, mucous membranes, and sometimes other tissues in the body, it’s not the only possible cause. These are some of the other germs to be aware of, per Medline Plus: (17)

• Other types of bacteria, including streptococci
• Fungi that cause yeast infections, athlete’s foot, and toenail infections
• Parasites that can cause head lice, body lice, or scabies
• Viruses that cause shingles, herpes, and warts

Some of the same preventive steps that can lower your risk of a staph infection, including keeping your hands and body clean and not sharing personal items such as towels and razors, can also help reduce your risk of skin infections from other causes as well.

Favorite Sites for Basic Staph Information

Mayo Clinic

Trusted resource Mayo Clinic breaks down what you need to know about staph in simple terms without dumbing it down. Who’s at risk? Yep, covered here. Different types of infections, from skin to food poisoning to blood infections? That’s here, too, along with what to tell your doctor about your symptoms and what sort of treatment might be prescribed.

MedlinePlus

When you want to dig deep into the topic of staph infections, MedlinePlus is the place to start, with links to articles on the kinds of infections staph can cause, research articles, Spanish-language resources, and ongoing clinical trials related to staph infections.

Favorite Resources on Lowering Your Risk and Preventing a Recurrence

Consumer Reports 

The gym can be a breeding ground for skin infections, including staph, which is why you hope the person who used the exercise machine before you wiped it off. But germs can lurk in other parts of the gym, such as the showers or the sauna. Consumer Reports tells you what to do to avoid bringing a skin infection home from the gym.

NYU Langone Health

A staph infection can lead to more serious infections, such as cellulitis. So how do you prevent a staph infection in the first place? This site tells you how.

KidsHealth

Kids and teens get staph infections, too, but frequent hand-washing and daily showering or bathing can help prevent them. Learn how to protect your home and family as well as how to recognize a staph infection should one occur.

Favorite Explainer on Antibiotic Resistance

World Health Organization

Bacterial infections occur worldwide, and effective antibiotics are needed to treat them. But when bacteria develop resistance to antibiotics — which tends to occur when antibiotics are given at low doses for short periods for viral infections — common bacterial infections, including some staph infections, become harder to treat. Learn what you can do as an individual to help control the spread of antibiotic resistance.