Impetigo symptoms, causes and treatment options

Impetigo is a highly contagious infection that frequently causes red sores and blisters to appear on the skin. It is also incredibly common among kids, affecting around 12 percent of children worldwide, which means it’s important to act fast when symptoms start to show up.

The good news is that the condition rarely leads to complications. Explore the rest of this article for easy-to-digest information on impetigo symptoms, treatment options and how to manage the infection.

In this article:

What is impetigo?

Impetigo is an easy-to-catch skin infection that causes red sores and blisters to form, usually around the nose and mouth. It’s itchy, painful, easy to spot and a common skin condition among kids.

The reason why impetigo doesn’t show up as often in adults is that their immune systems are typically more developed, offering better protection against these kinds of conditions. But because the infection is spread through close physical contact, parents are often exposed.

Impetigo usually appears after direct skin-to-skin contact, and the condition can also show up as a secondary infection where insect bites, eczema or herpes flare-ups are present.

To be clear, there are two types of impetigo infections to look out for:

Nonbullous impetigo

Nonbullous impetigo accounts for 70 percent of all cases . These infections can be recognized by yellow or honey-colored crusts, which form over the sores and blisters they cause.

Bullous impetigo

Bullous impetigo is known for causing larger sores on the skin. These lesions usually pop up in areas where the skin folds and touches other areas of the body. About 90 percent of bullous impetigo cases occur in children younger than 2.

Impetigo symptoms, causes and complications

When do impetigo symptoms start?

It can take as long as 10 days for symptoms of impetigo to show up after exposure, with small clusters of blisters beginning to form. Within 24 hours, these fluid-filled bumps will rupture and crust over.

Though impetigo typically appears around the nose and mouth, sores can also spread to other areas on the body:

• Arms and legs
• Ears and scalp
• Groin area
• Hands and feet

What does impetigo look like?

Red, weeping blisters and honey-colored crusts are obvious markers of impetigo. But these symptoms can look like other skin conditions, which is why impetigo is often confused with the following:

• Cold sores: fluid-filled blisters caused by the herpes simplex virus (HSV).
• Eczema: an inflammatory skin condition that affects both children and adults.
• Ringworm: a contagious fungal infection that infects the skin.
• Scabies: an itchy skin infection caused by tiny mites called Sarcoptes scabiei.

What causes impetigo?

Impetigo is caused by one of two bacteria:

• Staphylococcus aureus (staph): This bacterium causes most cases of bullous impetigo. It can also cause non-bullous nonbullous impetigo.
• Streptococcus pyogenes (group A strep): This bacterium can cause nonbullous impetigo. Streptococcus pyogenes is the same bacterium that causes strep throat.

Again, impetigo can spread through skin-to-skin contact and from sharing things like towels, clothing or other contaminated items. Cases of impetigo also tend to spike during the warmer months.

People also tend to spend more time outdoors during the spring and summer months, where they may suffer cuts or abrasions from activities like swimming or playing sports. This leaves the skin vulnerable to bacteria and infection.

What are the complications of impetigo?

Impetigo is not considered dangerous and clears up even faster with treatment. But complications can occasionally arise:

• Cellulitis: Cellulitis occurs when the infection spreads to the tissue under the skin, giving it access to both the lymph nodes and bloodstream. This condition has the potential to become life-threatening.
• Ecthyma: In rare cases, impetigo can evolve into ecthyma, an infection that progresses deeper into the skin, leaving patients vulnerable to secondary infections.
• Kidney problems: Post-streptococcal glomerulonephritis (PSGN) can occur after being infected with group A strep. Patients can experience kidney issues, and others might be at risk of long-term kidney damage.
• Scarring: It is rare, but scarring can result from impetigo. This usually happens when the infection penetrates deeper layers of the skin. Scratching at the blisters and picking scabs caused by the infection can also contribute to scarring.

How is impetigo diagnosed?

An official diagnosis requires a visit to the doctor’s office. There, a health care provider can examine the skin and identify the infection. In rare cases, providers may take swabs of a blister or sore and send it off for lab testing, but this only occurs when there are concerns that the infection has penetrated deep into skin or spread to multiple areas of the body.

How is impetigo treated?

Topical antibiotics can be used to treat impetigo. The Food and Drug Administration (FDA) has approved mupirocin 2 percent for prescription use in people 2 months of age or older. Those affected are not typically considered contagious after 24 to 48 hours of treatment.

It is also recommended to soak the affected areas in warm water or apply a wet cloth compress before applying medication. This can help remove scabs and allow the antibiotics to target the infection more effectively. Bandaging the area can help prevent the infection from spreading, too.

Preventing impetigo

Keeping clean is the best way to avoid impetigo. People should wash their hands often and avoid close contact with anyone showing signs of infection. (That also includes sharing items like razors, towels or anything else used primarily on the skin.)

If it's suspected that someone in the household has impetigo, disinfect doorknobs, countertops and all other surfaces that could have been touched. Wash clothes, towels or bedsheets that may have been used since symptoms began.

Outlook and prognosis

Impetigo is temporary. The infection typically clears within 7 to 10 days of starting antibiotics. (Without medication, recovery time can take up to two or three weeks.) However, the condition can return, and young children are especially prone to reinfection. Health care providers recommend those affected keep the blisters and sores clean, and follow the steps outlined above to avoid encountering the infection again.

Living with impetigo

Those with impetigo lesions on the skin should resist the urge to touch, scratch or rub them. This will only make it easier for the infection to spread. Keep nails trimmed and the infection clean and covered. Wash with soap and water, and repeat as often as health care providers recommend.

Until medication is made available, kids should stay home from school 24 to 48 hours after starting antibiotic treatment. Adults should avoid situations where close skin-to-skin contact is likely. If someone does need to leave the house, they can use nonstick bandages to decrease odds of spreading the infection.

This content is for informational purposes only and is not medical advice. Consult your health care provider before taking any vitamins or supplements and prior to beginning or changing any health care practices.