People with atopic dermatitis are more prone to infections of the skin, particularly those of the viral, bacterial, and fungal kind. In those with the condition, the immune system is more focused on allergies than fighting infections.
One theory is that the immune system, when overrun by allergies has fewer infection-fighting chemicals, giving various bacteria, especially Staphylococcus aureus, an easier shot at colonizing and even infecting the skin of people with atopic dermatitis. Also, those with atopic skin are also more susceptible to infection, because the barrier function of atopic skin is compromised. This means that the disease itself causes breaks in the skin, where infection-causing microorganisms can enter.
USA300 Strain of Staphylococcus aureus Bacteria.
RML/NIAID
Bacteria Colonization
Colonization and infection by Staphylococcus aureus cause various problems in people with atopic dermatitis. This bacterium not only causes skin infections such as impetigo but also produces bacterial toxins which can inflame the skin and disrupt the skin’s natural barrier function.
These bacterial toxins can worsen eczema, and treatment with antibiotics may improve flares of atopic dermatitis in some cases when typical anti-inflammatory medications such as topical corticosteroids are insufficient for management.
Fungal Infections
Fungal infections, such as tinea and yeast infections, are also more common in people with atopic dermatitis. This may be partially due to the use of topical steroids, which can suppress the immune system of the skin.
But, it may also be in response to the lack of special infection-fighting chemicals in the skin of people with atopic dermatitis. Treatment of fungal infections can improve the symptoms of atopic dermatitis.
Viral Infections
Viral infections are also more common in people with atopic dermatitis. People with atopic dermatitis and severe herpes infections require oral or intravenous antiviral medications to treat these infections.