Infected eczema

What is infected eczema?

Eczema, also known as atopic dermatitis, is a chronic skin condition characterised by dry, itchy skin that can become red and inflamed.^[1] When eczematous skin is scratched or damaged, it can break the skin barrier, making it open to various infections. If eczema is infected it’s referred to as ‘infected eczema’, which requires additional medication to ‘fight off’ the infections.

Infections are more common in people with eczema. This is because it makes your skin dry and less protected from harmful substances like microorganisms. As a result, you’re more susceptible to viral and bacterial infections.^[1]

To treat infected eczema, you’ll typically be prescribed oral antibiotics, topical steroids or both.

What types of infected eczema are there?

All forms of infected eczema are categorised as ‘secondary infections’, as the underlying cause of infection is another condition (eczema).^[2]

And secondary infections for eczema can be categorised into three main groups: bacterial, viral and fungal.

Bacterial infections – Staphylococcus aureus (SA) is the most common bacteria to cause infection in patients with eczema. The reduced barrier function and immune response allow SA to easily enter the skin and attach to it. SA then releases a number of toxins into your bloodstream, further impairing your immune response and causing inflammation.^[3] Typical symptoms of bacterial infections on eczematous skin include redness, severe itching, and inflammation. As the infection worsens, crusty, yellow skin can form. Bacterial infections tend to be easy to treat with either oral or topical antibiotics.

However MRSA, a resistant strain of SA, is more complicated to treat.^[3] MRSA, which stands for methicillin-resistant staphylococcus aureus, is a strain of bacteria resistant to common antibiotics. This means you need to find an antibiotic they aren’t resistant to to kill them, making the infection harder to treat. As MRSA can survive on objects like door handles and towels, it’s important to wash your hands thoroughly, and frequently use hand gels or antiseptics to prevent the infection’s spread.

Viral infections – People with eczema are more likely to be infected with certain viruses. These include:

• Eczema herpeticum (EH), which is caused by the herpes simplex virus when it develops in people with eczema. This virus is characterised by small, red, fluid-containing across your skin. Other symptoms include feeling hot and shivery, eczema that’s painful to touch and feeling unwell.^[4] EH is life-threatening. If you experience these symptoms, seek medical help right away. You should treat EH as soon as you see the first symptoms, as delaying it can cause complications to your health.^[5]
• Eczema coxsackium (EC) – Coxsackievirus is the most common virus to cause EC. Typical symptoms are painful blisters which can progress into scabs. It’s generally not itchy, and can be either local to eczematous skin or spread to other parts of your body. Treatment usually involves topical steroids and wet wrap therapy.^[6]

Fungal infections – Various species of fungus live naturally in your body and play an essential role in your gut’s microbiome. One species is Candida, which lives mainly in your mouth and gut.^[7] However, when it enters the bloodstream and spreads to other areas of the body, it can cause infections. Fungal infections are relatively easy to treat with topical or oral antifungals if they get worse.

How common is infected eczema?

It’s estimated that eczema affects up to 20% of children and 3% of adults^[8] and, as mentioned, there are three types of infections that can affect it: bacterial, viral and fungal. Bacterial infections caused by staphylococcus aureus are thought to affect about 90% of eczema patients. Most can be treated with prescription antibiotics, but in around 20% of cases, patients are hospitalised due to complications.^[9]

Viral infections, however, are less common. Eczema herpeticum affects less than 3% of patients with atopic dermatitis, most being children.^[10] Although it’s not as common, it’s more serious and can be life-threatening if not treated promptly.

The prevalence of fungal infections is unknown as there have been no studies investigating fungal infection in eczema patients.

What causes infected eczema?

To understand the cause of infected eczema, it’s important to understand how eczema develops. Eczema is a complicated disease. To date, scientists are still unsure of the exact cause of it. However, some mutations and alterations have been linked to its onset.

Eczema occurs on the outermost layer of your skin. In this layer, the protein filaggrin plays a necessary role. It helps to maintain moisture and creates a tough outer layer, forming a physical protective barrier. A mutation in the FLG gene reduces the amount of filaggrin produced.^[1] As a result, your skin can become dry, and its protective layer damaged. This allows bacteria, viruses and fungi to easily enter the compromised skin barrier and cause infections.^[2]

What symptoms does infected eczema cause?

Depending on your type of infection and the microorganism that’s causing it, your symptoms may vary.

Staphylococcus aureus is the most common bacterial infection in eczema patients. Symptoms of this infection include:

• itching;
• redness or darkened skin;
• yellow crusts on top of eczema;blister filled with pus;
• fever; and:
• pain.

And symptoms of viral infections can depend on the type of viral infection.

Typical symptoms of eczema herpeticum include:

• worsened, painful eczema;
• a cluster of blisters filled with fluid that breaks open and leaves sores on the skin; and:
• feeling hot and shivery at the same time.

Whereas typical symptoms of eczema coxsackium include:

• painful vesicles;
• scabby or eroded skin;
• fever;
• sore throat; and:
• a rash.

Can infected eczema lead to other problems?

Bacterial infections don’t typically result in further complications once treated. While MRSA infections may be more difficult to treat and may require hospitalisation, they can often be treated successfully at home as well.

Secondary viral infections, with eczema as the underlying cause, are harder to treat. Eczema herpeticum is a potentially life-threatening condition. If not treated quickly, it can cause serious health complications.

Eczema can also make some conditions harder to treat, such as chicken pox.^[3] Chickenpox is a common infection that affects most children across the world at some point, but in children with eczema the symptoms can worsen and cause complications. So when children with eczema get chicken pox, it’s important to closely monitor them with frequent temperature checks and check whether their eczema has developed any lesions or blisters.