What Causes Staph Infections, and How Can You Avoid Them?

The bacteria that causes a staph infection, staphylococcus aureus, is all around you all the time. It lives on surfaces and on the ground. You might also carry it on your skin and in your nose. So how does it go from harmless companion to troublesome foe?

“Typically, we get along with staphylococcus just fine,” says family medicine physician Donald Ford, MD, MBA. But when staph enters your body through a nick or cut in your skin, it may result in an infection.

These infections are usually minor and can be treated with antibiotics. Staph can become much more serious, though — even life-threatening — if it somehow finds its way into your bloodstream, lungs, bones, joints or heart.

Different types of staph infections

A staph infection might show up on your skin as:

• Blisters: These look similar to whiteheads or pimples. Once they break open and the pus drains out, the infection’s threat goes away.
• Boils: Boils are deeper than blisters and are often painful. The skin surrounding a boil appears red, swollen and sore.
• Impetigo: This is a contagious skin rash that sometimes secretes fluid that forms a yellow crust over the rash. Though impetigo is painful or itchy, it’s typically not serious. It’s most common in children.
• Cellulitis: If your infection gets under the layers of your skin and spreads, it could cause skin inflammation called cellulitis. Your skin will look red and swollen and may be warm to the touch. You may even develop sores. Cellulitis can become more serious if it’s not treated immediately.

Most staph infections on the skin are easy to treat and typically respond well to antibiotics or by draining the infected area, Dr. Ford says.

“We treat more superficial skin infections such as impetigo for a few days,” he says. “A deeper boil or an abscess may need to be drained and can take up to a few weeks to heal.”

When staph is serious

If staph moves deeper into your body, it becomes dangerous and may require a longer course of treatment — or even hospitalization.

Serious forms of a staph infection include:

• Endocarditis: Endocarditis occurs when staph enters your bloodstream and attacks your heart. Doctors typically treat it with strong antibiotics. Surgery is sometimes necessary if the infection damages your heart valves.
• Sepsis: If your infection is severe, it can enter your bloodstream. This is known as sepsis. It can cause fever and dangerously low blood pressure, and is especially dangerous to older adults.

Some staph bacteria have become resistant to the antibiotics used to treat them. This is known as MRSA, which stands for methicillin-resistant staphylococcus aureus.

Most MRSA infections are skin infections, but it can also cause more serious infections. The infected wound may require surgical or local drainage. Your doctor likely will prescribe a stronger antibiotic to treat it as well.

How to avoid a staph infection

Since staph is all around us, it’s not uncommon for a perfectly healthy person to get a staph infection. The best way to avoid it is to maintain good hygiene, Dr. Ford says.

• “Wash your hands, particularly after you’ve been working in the soil or working with food products,” he says.
• “Make sure food is properly prepared, clean and fresh because if your food gets exposed to staph you can get staph-related food poisoning,” he says.
• If you get a cut on your skin, treat it immediately. Wash it with soap and water, dry your skin and cover it with a bandage.

If you think you have a staph infection, Dr. Ford suggests bringing it to your doctor’s attention or going to an emergency care center.

“Staph is sometimes a serious infection if left untreated. So it’s always a good idea to go see your doctor or another health care provider if you’re worried you might have a staph infection,” Dr. Ford says.