A staph infection is any infection caused by Staphylococcus aureus, a type of bacteria that naturally lives on the skin and inside the nose of about 30% of people. Most of the time, these bacteria cause no problems at all. But when they enter the body through a cut, scrape, or other break in the skin, they can cause infections ranging from minor skin irritations to serious, life-threatening conditions.
How Staph Bacteria Spread
Staph bacteria spread through direct skin-to-skin contact, shared personal items, and contaminated surfaces. The bacteria can survive on dry surfaces for extended periods, which is why gym equipment, shared towels, and locker rooms are common transmission points. You can also spread staph from one part of your own body to another simply by touching a colonized area and then touching a wound.
Athletes in contact sports like wrestling, football, and rugby face especially high risk because of repeated skin-to-skin contact, shared equipment, and cuts or abrasions that go uncovered. But staph infections also show up in soccer, basketball, martial arts, rowing, and other sports where people share facilities and gear.
Common Skin Infections
Most staph infections affect the skin. The three you’re most likely to encounter are boils, cellulitis, and impetigo.
Boils and abscesses are the most recognizable form. They start as a red, swollen, painful lump filled with pus, usually around a hair follicle. They can appear anywhere on the body but tend to show up in areas prone to friction or sweating, like the armpits, groin, and thighs. A single boil is usually manageable, but clusters of boils (called carbuncles) signal a more aggressive infection.
Cellulitis is an infection of the skin and the tissue just beneath it. It typically starts at the site of a small wound that wasn’t properly cleaned or covered. The affected area becomes red, warm, swollen, and tender, and the redness can spread quickly. Unlike a boil, cellulitis doesn’t produce a visible pocket of pus. It sits deeper in the tissue.
Impetigo is highly contagious and mostly affects children. It shows up as itchy sores or blisters, often around the nose and mouth, that burst and leave a yellowish-brown crust. It spreads easily in schools and childcare settings through direct contact.
When Staph Becomes Dangerous
In some cases, staph bacteria enter the bloodstream, joints, bones, lungs, or heart. These invasive infections are far less common than skin infections but far more serious. Symptoms that suggest an infection has moved beyond the skin include high fever, chills, rapid heartbeat, muscle aches, and a general feeling of being very unwell.
Toxic shock syndrome is one of the most severe staph complications. It’s caused by toxins that certain strains of staph release into the body. Symptoms come on suddenly and include high fever, confusion, a widespread red rash that looks like a sunburn, low blood pressure, nausea, vomiting, and diarrhea. The rash later peels, particularly on the palms and soles of the feet. Without rapid treatment, toxic shock syndrome can cause organ failure, especially in the kidneys and liver.
MRSA: The Resistant Strain
Not all staph infections are the same. Most are caused by strains that respond well to standard antibiotics. MRSA (methicillin-resistant Staphylococcus aureus) is a strain that has developed resistance to many common antibiotics, including penicillin-type drugs and cephalosporins. This makes it harder to treat, though not impossible.
MRSA used to be primarily a hospital problem, picked up during surgeries or long stays with IV lines and catheters. Since the 1980s, though, community-acquired MRSA has been rising steadily. This version spreads in gyms, locker rooms, schools, and households. Hospital-acquired MRSA tends to be resistant to a wider range of antibiotics than the community-acquired version, but both require careful antibiotic selection.
From the outside, an MRSA skin infection looks identical to any other staph skin infection. The only way to know the difference is through lab testing, which is why infections that don’t improve with initial treatment often get cultured.
How Staph Infections Are Diagnosed
Doctors can often identify a staph skin infection just by examining it. When confirmation is needed, or when the infection isn’t responding to treatment, they’ll take a sample of pus, tissue, or fluid and send it to a lab to identify the specific bacteria and determine which antibiotics will work against it. For suspected bloodstream or internal infections, blood and urine cultures are used.
Imaging tests like CT scans, MRIs, or echocardiograms (ultrasounds of the heart) come into play when doctors suspect the infection has spread to bones, joints, or heart valves.
How Staph Infections Are Treated
For boils and abscesses, the primary treatment is incision and drainage, where a doctor opens the abscess and lets the pus drain out. This alone resolves many infections. Adding an antibiotic after drainage reduces the chance of treatment failure by about 5% at one month and lowers the risk of the infection coming back by about 8% over three months.
The antibiotics most effective for skin abscesses, including those caused by MRSA, are typically taken for 7 to 10 days. Some are taken twice daily, others three or four times daily, and they’re often combined with over-the-counter pain relievers. Older antibiotic classes like cephalosporins, which doctors sometimes prescribe out of habit, don’t actually improve outcomes for most skin abscesses beyond what drainage alone achieves, so guidelines recommend against using them for this purpose.
Cellulitis and impetigo are treated with antibiotics alone, since there’s no pus pocket to drain. Mild impetigo sometimes responds to topical antibiotics applied directly to the sores. More severe or widespread infections require oral antibiotics. Invasive staph infections that reach the blood, heart, or bones require intravenous antibiotics given in a hospital setting, often for weeks.
Reducing Your Risk
Most staph infections are preventable with basic hygiene. The single most important step is keeping any break in the skin, no matter how small, clean and covered with a bandage until it heals. Staph bacteria need an entry point, and an uncovered wound is an open invitation.
Beyond wound care, these habits make a real difference:
- Wash your hands frequently with soap and water, or use alcohol-based hand sanitizer.
- Don’t share personal items like towels, razors, clothing, or cosmetics.
- Wash contaminated fabrics in hot water, including towels, sheets, and clothing that have touched an infected area.
- Shower after exercise and before using shared equipment again.
- Clean shared equipment with antiseptic wipes before use, and place a towel between your skin and gym surfaces or sauna seating.
- Avoid shared whirlpools or saunas if someone with an open wound has used them.
If you do develop a skin infection, avoid touching it unnecessarily, wash your hands immediately after any contact with the area, and keep it covered. Staph spreads easily from person to person and from one body site to another, so containment matters as much as treatment.