When areas of Skin affected by atopic dermatitis (AD) morph from itchy, red patches to oozy or crusty blisters or sores, you’re probably dealing with more than a flare. In all likelihood, you’ve developed an infection.

It’s not an uncommon complication of AD (the most common type of eczema). Research shows people with atopic dermatitis are more likely than those who don’t have the condition to develop bacterial and viral skin infections.

But, even though you may be at increased risk of a skin infection thanks to AD, you aren’t guaranteed to develop one. There are ways to help keep bacteria and other pathogens from (literally) getting under your skin. And, if you do wind up with an infection, prompt treatment should clear it right up.

Why Skin Infections Occur With Atopic Dermatitis

Everyone’s skin has its own unique microbiome — a diverse community of microorganisms that form a barrier, which helps protect your skin against pathogens. Key components of this microbiome are peptides (chains of amino acids) that help keep potentially harmful microbes in check.

People with atopic dermatitis have a breakdown in this skin barrier — specifically, lower-than-normal amounts of certain infection-fighting peptides in the skin. This makes people with AD more susceptible to harmful viruses and bacteria that can enter the skin and cause infections, says Ahmad Amin, MD, a dermatologist who specializes in atopic dermatitis and eczema at Northwestern Medicine in Chicago.

Two pathogens in particular are known to cause infections in skin affected by atopic dermatitis:

• Staphylococcus: The type of bacteria most likely to enter skin is Staphylococcus, which resides on the skin of 30 to 50 percent of all people and is likely even more common in people with eczema. While staph doesn’t usually cause problems, some bacteria — most commonly, S. aureus — can enter through broken skin and cause an infection. Staph infections occur more frequently in people with AD, which can then lead to eczema flares.
• Herpes simplex virus: The herpes simplex virus affects two-thirds of all people worldwide. A person with AD who’s been infected with herpes simplex can develop a severe skin condition, known as eczema herpeticum, that causes an eruption of skin sores throughout the body, particularly in areas where there is atopic dermatitis, says Dr. Amin.

Signs of Infection

At first glance, it may be hard to tell the difference between a garden-variety atopic dermatitis flare and an AD-related skin infection. But, there are several visual symptoms of the latter to be aware of:

• Red sores that are warm to the touch, especially if they secrete yellowish fluid or develop a honey-colored crust
• Round, punched-out sores, especially in areas where eczema is flaring
• Bumps that resemble pimples or boils — red, swollen, and painful

If the infection is severe enough to spread to parts of the body other than skin, you may develop a fever.

Another sign: AD symptoms that aren’t improving with your usual treatments. “[Atopic dermatitis] will not get better until the infection is treated first,” says Amin.

If you experience any of these symptoms, see your doctor to get a definitive diagnosis of infection and find out what caused it.

Treatment and Prevention

If you have a mild bacterial infection, your doctor will likely prescribe an antibiotic cream or ointment. If a large area of skin is affected or you have a lot of oozing and crusting, you may need to take an oral antibiotic for a few days to control the infection, says Amin.

In the case of eczema herpeticum, your doctor will prescribe an oral antiviral medication to treat the Herpes Simplex Virus. “Herpes infections can be easily managed if you catch them early on,” says Amin.

As for guarding against infections, talk to your dermatologist about taking bleach baths once or twice a week, or regularly use a body wash that contains sodium hypochlorite. Keep in mind, though, that skin care measures like these may not be very effective if you aren’t treating your AD. This may mean considering targeted systemic therapy if less aggressive treatments aren’t working.

And, as tempting as it may be to scratch an itchy patch of AD, scratching can cause breaks in the skin, allowing bacteria and viruses inside, says Amin.

“Getting good control of your atopic dermatitis is the best way to prevent and reduce your chance of getting a skin infection,” says Amin.