What is Eczema Herpeticum?
Eczema herpeticum (EH) is a skin infection caused by the herpes simplex virus, which occurs in individuals with atopic dermatitis, a type of skin condition. This infection often appears suddenly, characterized by small blisters and “punched-out” wounds that scab over and bleed in areas affected by eczema. It can sometimes cause flu-like symptoms in patients, such as fever, swollen lymph nodes, and a general feeling of illness.
The disease severity can significantly vary from person to person. In healthy adults, it may be mild and resolve on its own, while in children, infants, and individuals with weakened immune systems, it can be life-threatening. Starting antiviral medications promptly can decrease the duration of mild conditions and prevent severe disease, reducing risks of disability and death.
What Causes Eczema Herpeticum?
Eczema herpeticum is a skin condition that often happens when the herpes simplex virus, usually HSV-1, infects the skin of someone with atopic dermatitis, another type of skin condition. This typically occurs when the virus, which is already present in the person’s body, becomes active again. It’s more common for the virus to reactivate than for someone to get infected from scratch.
People with atopic dermatitis often get recurring skin infections because their skin doesn’t do a good job of keeping out bacteria and viruses. This is due to the skin not forming a strong barrier and the immune system not working as it should.
A similar infection, called Kaposi varicelliform eruption (KVE), can occur in people with other skin conditions that also weaken the skin barrier. KVE has been seen in people with skin conditions like Darier disease, Hailey–Hailey disease, burns, contact dermatitis, mycosis fungoides, Sézary syndrome, ichthyoses, and pityriasis rubra pilaris.
People are more likely to develop eczema herpeticum if they have a severe form of atopic skin disease, their skin doesn’t produce enough of certain proteins (like filaggrin) that help form a barrier, or their skin is low on substances called antimicrobial peptides that help fight off bacteria. Eczema herpeticum patients often have particular markers in their bodies, like low levels of a substance called interferon, high eosinophil counts (a type of white blood cell), and high levels of IgE (a type of immune protein). They’re also more likely to have allergies to food and the environment, asthma, and a history of atopic dermatitis developing before they turned five. Additionally, they are likely to have had Staphylococcus aureus and molluscum contagiosum infections. There is also an association between those who have the HLA-B7 gene and an increased chance of getting eczema herpeticum.
There’s a shift in the immune system in people with eczema herpeticum towards what’s called a Th2 response. This response is linked to lower levels of antibacterial substances in the skin, reducing the skin’s ability to fight off a herpes simplex virus infection. The presence of substances called interleukin-10 (IL-10) and IL-25 around the area of the eczema herpeticum might also play a role in causing this condition.
Risk Factors and Frequency for Eczema Herpeticum
Eczema herpeticum is a condition that happens in less than 3% of patients with atopic dermatitis, a type of skin inflammation. This condition often affects babies and children more than it does adults. Atopic dermatitis is a common skin problem worldwide, affecting around 10 to 20% of children in developed countries and 7 to 10% of adults in the United States. Despite a large number of people being exposed to the herpes simplex virus (which is involved in eczema herpeticum), the fact that only a small number of individuals with atopic dermatitis develop eczema herpeticum suggests that various factors unique to each individual play a significant role.
- The risk factors for hospitalization due to eczema herpeticum in children include being a boy, being less than one year old, having a fever, and feeling unwell overall when they first arrive at the hospital.
- According to a study in the US, the average age of children with eczema herpeticum who ended up in the hospital was a little over three years old and about 42% of these patients were girls.
- The same study found that Asian children had higher rates of hospitalization, longer hospital stays, and more expensive care costs related to eczema herpeticum.
- Currently, not much is known about how eczema herpeticum affects individuals who are not hospitalized and adults.
Signs and Symptoms of Eczema Herpeticum
Eczema herpeticum is a condition that appears suddenly with distinctive symptoms. It starts with dome-shaped blisters, each 2 to 3 mm in size, appearing in groups on a red base of skin. These blisters often appear on the face, neck, and upper trunk over areas already affected by atopic dermatitis, a type of eczema. The blisters can be itchy, painful, and can spread to areas of normal skin over a period of seven to ten days.
Within two weeks, these blisters tend to burst, leaving behind small, ‘punched-out’ erosions (small, shallow hollows) in the skin, which often have a crust that looks like dried blood. These small skin hollows may merge to form larger ones, creating a scalloped border around the edges.
The blisters can appear in waves, with different shapes and sizes that can be seen at the same time. If secondary infection occurs, the resulting impetigo can create a crust over the blisters that looks like dried honey. Patients with severe or poorly controlled atopic dermatitis might have a hard time recognizing these symptoms because they can mimic an eczema flare.
- Sudden onset of dome-shaped, grouped blisters
- Itchy, painful blisters that spread to normal skin
- ‘Punched-out’ skin erosions with crust
Patients may also experience symptoms like fever, malaise (general discomfort or uneasiness), and swollen lymph nodes. However, within six weeks, the skin generally heals without leaving a scar.
Testing for Eczema Herpeticum
If your doctor suspects you have eczema herpeticum, a type of skin condition, they may be able to make a diagnosis based on its unique appearance. If they need more certainty, they can perform a test called a viral polymerase chain reaction (PCR). This is a type of test that analyzes the fluid from the skin’s blisters to confirm the diagnosis and identify what type of herpesvirus is causing your symptoms. The PCR test is highly accurate and robust.
If the PCR test is not available, your doctor has other options. They could use a Tzank smear, direct fluorescent antibody (DFA) testing, or viral cultures, which are all different types of tests to confirm a herpesvirus infection. If there’s a chance bacteria is complicating your condition, your doctor may also perform a bacterial culture. This means they’ll take a small sample and try to grow the bacteria in a lab to see what types are present.
A skin biopsy might be needed if your symptoms don’t typical look like eczema herpeticum. This involves taking a small piece of skin and examining it under a microscope. Also, certain blood tests can help. Your doctor might find that you not only have fewer lymphocytes, a type of white blood cell, but also that your erythrocyte sedimentation rate is higher, which is an indication of inflammation in your body.
Treatment Options for Eczema Herpeticum
If you have eczema herpeticum, a skin infection, it’s vital to begin treatment right away. Quick treatment with medications like acyclovir or valacyclovir can lessen your chances of severe complications and prevent the disease from getting worse.
In mild cases, oral acyclovir or valacyclovir can be used until all sores have scabbed over. For more severe cases or for patients with weakened immune systems, hospitalization may be necessary. These patients may require acyclovir given through an IV until they start to improve and their sores begin to scab. Once improvement is seen, they can switch to oral medication.
While treating eczema herpeticum, it can be helpful to use gentle skin moisturizers and cool compresses for relief. If you become seriously ill, you may need to receive fluids and nutrition through an IV, manage electrolyte levels, take care of your wounds, and control pain.
Preventing the spread of this infection to other parts of your body is important. To do this, washing your hands often is encouraged. Sores from eczema herpeticum are contagious until they’ve scabbed over.
If you’re admitted to the hospital, certain measures will be taken to avoid infecting others. These precautions might include isolating you in your own room and having healthcare providers wear masks and gowns when they are in your room. Healthcare providers will also monitor for any new infections and may provide antibiotics based on the results of any cultures taken.
What else can Eczema Herpeticum be?
When a doctor is trying to diagnose a skin condition known as eczema herpeticum, there are other illnesses with similar symptoms that they need to consider. These could include:
- Impetigo
- Hand-foot-and-mouth disease
- Eczema coxsackium
- Primary varicella infection (chickenpox)
- Disseminated herpes zoster (shingles)
- Disseminated molluscum contagiosum (a viral skin infection)
- Acute generalized exanthematous pustulosis (a reaction to medications)
- Dermatitis herpetiformis (an itchy rash linked to gluten sensitivity)
- Cellulitis (a common skin infection)
- Erysipelas (a bacterial skin infection)
Mistaking eczema herpeticum for one of these other conditions can lead to a delay in the right treatment, which can then lead to further issues. Signs that the condition is likely to be eczema herpeticum include painful lesions, lesions that are the same size, and distinctive ‘punched-out’ erosions in areas where the patient already has atopic dermatitis (eczema). Unlike shingles, eczema herpeticum doesn’t confine itself to specific areas of the skin.
What to expect with Eczema Herpeticum
Eczema herpeticum is a serious disease that could be life-threatening due to risks like body-wide viral infection, bacterial infection, and fungal infection which could cause multiple organs to fail. Earlier on, before the use of a drug called acyclovir, mortality rates in patients with this condition were between 10% and 50%. Thankfully, since the adoption of antiviral treatment, death rates have significantly reduced.
In a study conducted in 2011, involving 1331 children with this condition who were hospitalized in the United States, there were no recorded deaths, thus indicating a low mortality rate among hospitalized patients. On average, the children were hospitalized for just three days. However, 9.2% of them had to stay in the hospital for more than a week and 3.8% had to be in intensive care.
In a more recent study in 2018 with 4655 children, it was found that the mortality rate was very low, standing at 0.1%. Furthermore, 98.1% of the patients were considered at low risk of death. As for their ability to function, the majority only experienced a minor loss, while 33.1% experienced moderate loss and only a small 4.5% were categorized as having a major loss of function.
Possible Complications When Diagnosed with Eczema Herpeticum
EH, or Eczema Herpeticum, can lead to several potential complications. One of the most common issues that may arise is a skin infection caused by certain bacteria such as Staphylococcus aureus (S. aureus), Streptococcus pyogenes, and the molluscum contagiosum virus. According to a study, one-third of hospitalized children with EH had an S. aureus infection. In addition to this, some of these children also had methicillin-resistant S. aureus and a bloodstream infection. Most infected children were treated with oral or intravenous antibiotics.
Another potential complication is harm to the brain or eyes, which could lead to scarring or even blindness. In rare cases, the virus can spread throughout the body, potentially leading to serious issues like suppression of the bone marrow, widespread blood clotting within the body’s small blood vessels, and even death.
Common Complications:
- Skin infection with S. aureus, Streptococcus pyogenes, and the molluscum contagiosum virus
- Methicillin-resistant S. aureus infection
- Bloodstream infection
- Brain inflammation
- Eye infection leading to scarring or blindness
- Widespread HSV infection leading to bone marrow suppression and widespread blood clotting
- Potential death
Preventing Eczema Herpeticum
Those diagnosed with eczema herpeticum, a severe skin infection, must know that they could pass on the infection until the skin lesions haven’t fully healed and formed a crust. As a result, they should refrain from close interactions with others until that point. It also helps if patients avoid scratching the spots and wash their hands regularly to prevent spreading the virus to other parts of their own body, a process termed ‘autoinoculation.’
Patients with light eczema herpeticum symptoms who are treated at home must be warned to immediately seek medical help if they observe their symptoms worsening, such as a more severe rash or systemic symptoms – signs that the infection is affecting the body as a whole. It’s possible that they might need to be hospitalized and receive stronger treatments like acyclovir (a medicine used for treating viral infections) delivered directly into their bloodstream or antibiotics.
