GUIDE
Eczema herpeticum is a herpes virus superinfection of eczema skin. It is a medical emergency that requires hospital treatment.
If your baby has eczema and you are seeing clusters of small, painful, punched-out blisters or erosions — especially after exposure to someone with a cold sore — stop reading and go to the ER. This is not a bad flare. This is a viral infection spreading across your baby's damaged skin barrier, and it needs IV antiviral medication now. If you are here to learn and prepare, keep reading.
Here is the short version: your baby has eczema, which means their skin barrier is broken. The herpes simplex virus (HSV) — the same virus that causes cold sores — gets onto that broken skin and goes wild. Instead of a single cold sore on a lip, the virus spreads across the eczema-damaged areas, causing a widespread, painful, potentially life-threatening infection.
This is called eczema herpeticum, and it is one of the few true dermatologic emergencies in pediatrics.
In a person with a healthy skin barrier, HSV stays contained — one cold sore, maybe a cluster of blisters, limited to a small area. The intact skin acts as a wall the virus cannot cross. But eczema skin has no wall. The barrier is full of gaps, and HSV exploits every single one. It spreads rapidly across eczematous areas, creating dozens or hundreds of lesions in hours to days.
The danger is not just the skin infection. HSV can disseminate — spreading from the skin to the eyes (risking permanent vision loss), to the brain (herpes encephalitis), or to internal organs. In young infants especially, disseminated HSV can be fatal. This is why eczema herpeticum is treated with IV antiviral medication in a hospital, not with a topical cream at home.
The most common way a baby gets eczema herpeticum: someone with a cold sore kisses them.
Eczema herpeticum looks different from an eczema flare — but if you have never seen it before, the difference might not be obvious until you know what to look for.
What eczema herpeticum looks like:
What makes it different from a regular flare:
If you are looking at your baby's skin and thinking "this does not look like the usual flare" — trust that instinct.
| Feature | Eczema Flare | Eczema Herpeticum | Impetigo |
|---|---|---|---|
| Cause | Skin barrier dysfunction triggered by irritants, allergens, dryness, or illness | Herpes simplex virus (HSV-1 or HSV-2) infecting eczema-damaged skin | Staphylococcus aureus or Group A Strep bacteria entering broken skin |
| What it looks like | Dry, red, rough, scaly patches. May be weepy during bad flares. Same pattern your baby usually gets, just worse. | Clusters of small, uniform, punched-out erosions or tiny dome-shaped vesicles. Often described as looking like someone pressed a hole punch into the skin. | Honey-colored crusted sores. May start as fluid-filled blisters that rupture and form golden-yellow crusts. |
| Pain vs. itch | Primarily itchy. Baby scratches and rubs. | Primarily painful. Baby cries and pulls away when the area is touched. | Mildly itchy or painless. Usually does not seem to bother the baby much. |
| Fever | No fever (unless a separate illness is triggering the flare) | Fever is common — often 101-104°F. Baby looks and acts sick. | Usually no fever unless the infection is extensive or has spread deeper. |
| How fast it spreads | Gradual worsening over days | Rapid spread over hours to days. New clusters keep appearing. | Moderate spread over days. New sores appear where baby scratches. |
| Location | Same areas that always flare — cheeks, creases, etc. | Often starts on the face or areas of active eczema, then spreads. Can become widespread. | Typically around the mouth and nose, but can appear anywhere. |
| Treatment | Moisturizer, topical steroids, trigger avoidance | IV acyclovir in hospital. STOP topical steroids immediately. | Topical or oral antibiotics |
| Urgency | Manage at home. See pediatrician if not improving. | Emergency. Go to the ER now. | See pediatrician within 24 hours. Not an emergency unless spreading rapidly. |
Do not wait for a pediatrician appointment. Do not wait until morning. Eczema herpeticum is treated in the emergency room with IV antiviral medication. Time matters — the sooner treatment starts, the better the outcome.
The easiest way to spot something abnormal is to know what normal looks like for your baby. Log eczema flares in tinylog — severity, location, what the skin looks like — so you have a baseline. When something changes, you will notice it faster and describe it more clearly to the ER team.
The virus behind eczema herpeticum is herpes simplex virus, usually HSV-1 (oral herpes, the cold sore virus), though HSV-2 (genital herpes) can also cause it. The transmission route is almost always direct skin-to-skin contact with someone who has an active herpes outbreak — or who is about to have one.
The most common scenario: A well-meaning family member who has a cold sore (or is in the prodromal stage — that tingling feeling before a sore appears) kisses the baby. The virus lands on the baby's eczema-affected skin. Within 2-7 days, eczema herpeticum develops.
Why eczema skin is so vulnerable: Healthy skin has multiple layers of defense against viral invasion — an intact stratum corneum, antimicrobial peptides, tight junctions between cells. Eczema disrupts all of these. The skin barrier is literally full of microscopic holes. HSV, which normally struggles to get past intact skin, finds an open highway. It infects the keratinocytes (skin cells), replicates rapidly, and spreads laterally across the damaged areas.
Risk factors that make eczema herpeticum more likely:
The bottom line: any baby with eczema who is exposed to HSV is at risk. The worse the eczema, the higher the risk — but even mild eczema can develop eczema herpeticum if the exposure is there.
If your baby is diagnosed with eczema herpeticum, they will be admitted to the hospital. This is not outpatient treatment — it requires IV medication and monitoring. Here is what to expect so you are not blindsided.
| Phase | What Happens | When |
|---|---|---|
| ER evaluation | The medical team will examine the skin lesions and likely perform a viral swab (HSV PCR or direct fluorescent antibody test) to confirm the diagnosis. They will check for eye involvement and systemic signs. | First 1-2 hours |
| IV acyclovir started | Acyclovir is the antiviral medication that fights HSV. It is given intravenously (through an IV line) because the infection needs aggressive systemic treatment, not just topical cream. The dose is based on your baby's weight. | As soon as diagnosis is suspected — they do not wait for test results to confirm |
| Topical steroids stopped | If your baby was using topical corticosteroids for eczema, these will be stopped immediately. Steroids suppress the local immune response, which is exactly the opposite of what you want when fighting a viral infection. | Immediately |
| Monitoring and supportive care | Your baby will be monitored for complications — especially eye involvement and signs of disseminated infection (HSV spreading to the brain, liver, or other organs). Pain management, hydration, and fever control. | Throughout hospital stay |
| Transition to oral acyclovir | Once the lesions stop spreading and begin to crust over, and your baby is feeding and stable, the team will switch from IV to oral acyclovir to complete the treatment course. | Usually after 3-5 days of IV treatment |
| Discharge and follow-up | You will go home with oral acyclovir to complete the course (typically 10-14 days total antiviral treatment). Follow-up with your pediatrician and dermatologist to restart eczema management carefully — without topical steroids initially. | Hospital stay is typically 5-7 days total |
Eczema herpeticum is preventable. Not 100% of the time — you cannot control every exposure — but the vast majority of cases come from a known, avoidable transmission route: direct contact with someone shedding HSV, usually through kissing.
These rules are not suggestions. For a baby with eczema, they are as important as any other safety measure you take.
| Rule | Why It Matters |
|---|---|
| No kissing the baby if you have a cold sore — period | This is the single most important prevention rule. HSV-1 is most commonly transmitted by kissing. If you have an active cold sore, or feel the tingling that means one is coming, do not kiss your baby anywhere — not on the lips, not on the cheeks, not on the hands. The virus sheds from the moment you feel the tingle until the sore is completely healed. |
| Tell your family and visitors the rule | This is the hard conversation. Grandparents, aunts, uncles, friends — anyone who gets cold sores needs to know they cannot kiss your baby when they have one (or feel one coming). People will think you are overreacting. You are not. Show them this guide if you need backup. |
| Know that HSV sheds before the sore appears | The virus becomes contagious during the prodromal phase — the tingling, burning, or itching sensation that precedes a visible cold sore by 1-2 days. If someone says 'I think I might be getting a cold sore,' they are already contagious. |
| Wash hands before touching the baby's skin | If you have a cold sore, wash your hands thoroughly and frequently. HSV can transfer from your lip to your fingers to your baby's skin. Do not touch your cold sore and then touch your baby. |
| Do not share items that touch mouths | Utensils, cups, pacifiers, towels, washcloths — anything that contacts the mouth of someone with HSV can transfer the virus. Use separate items during an outbreak. |
| Keep eczema well-managed | The better your baby's eczema is controlled, the stronger their skin barrier, and the harder it is for HSV to establish infection. Consistent moisturizing is not just about comfort — it is about defense. |
| Have an action plan if there is a known exposure | If your baby with eczema was kissed by someone who later realized they had a cold sore, call your pediatrician. They may recommend watchful waiting with clear instructions on what to look for, or in some cases, prophylactic antiviral medication. |
If your baby was around someone with a cold sore, log it in tinylog right away. If something unusual shows up on the skin 2-7 days later, you will have the exposure date documented — which helps the ER team act faster and confirms the diagnosis.
HSV is a lifelong virus. Once your baby is infected, the virus retreats into nerve ganglia and stays dormant — potentially reactivating later, especially when the immune system is stressed or the skin barrier is compromised during eczema flares.
Recurrences of eczema herpeticum do happen, but they tend to be milder than the first episode and can often be treated with oral antiviral medication at home if caught early. The key is having a plan.
| Action | Details |
|---|---|
| Learn your baby's warning signs | The first episode teaches you what eczema herpeticum looks like on your child's skin. Take photos (with your doctor's guidance) so you have a reference for comparison. Recurrences often start in the same location. |
| Get a standing prescription for oral acyclovir | Many pediatricians will provide a prescription for oral valacyclovir or acyclovir that you can fill and keep on hand. At the first sign of recurrence, you can start treatment immediately rather than waiting for an appointment. |
| Start treatment at the first sign — do not wait | If you see vesicles or punched-out erosions forming on eczematous skin, start oral acyclovir and call your pediatrician. Early treatment of recurrences can prevent hospitalization. |
| Be extra vigilant during eczema flares | Recurrences are more likely when eczema is actively flaring because the skin barrier is at its weakest. During a bad flare, be extra cautious about HSV exposure and watch the skin more closely for herpetiform changes. |
A bad eczema flare looks scary but is not dangerous. Eczema herpeticum looks different — and it is dangerous. The key distinction is pain versus itch, and uniform punched-out lesions versus the rough, patchy dryness of eczema. Trust your gut. If the skin looks like something you have never seen before on your baby — not just 'worse eczema' but genuinely different — get it evaluated urgently.
This sounds strange, but take photos of what your baby's typical eczema flare looks like. Store them on your phone. When something new and alarming shows up on the skin, you can compare it to what you know is 'just eczema.' If the new lesions look fundamentally different — especially if they are painful vesicles instead of itchy dry patches — that comparison helps you make the call to go to the ER.
This is critical. If you suspect eczema herpeticum, do not put topical steroids on the lesions. Your instinct will be to treat what looks like a bad eczema flare with the prescription cream — but if it is actually HSV, steroids suppress the immune response and help the virus spread faster. When in doubt, skip the steroid and go get evaluated.
Telling your family 'do not kiss my baby if you have a cold sore' is awkward. It might hurt feelings. Grandma might roll her eyes and say she has had cold sores her whole life and all her kids turned out fine. But her kids probably did not have eczema, and the combination of HSV plus eczema is what makes this dangerous. Have the conversation. Be direct. You are protecting your child from a preventable emergency.
About 50-80% of American adults carry HSV-1 (oral herpes). Most were infected in childhood and many do not even know they carry it. Cold sores are so common that people treat them as trivial. For a healthy adult, they are trivial. For a baby with eczema, they are a potential medical emergency. The mismatch between how common HSV is and how dangerous it can be in eczema babies is exactly why awareness matters.
If eczema herpeticum lesions are on or near the eyelids, or your baby's eye appears red, swollen, or weepy, make sure the ER team knows immediately. Herpes keratitis — HSV infection of the cornea — can cause permanent scarring and vision loss. An ophthalmology consultation in the ER is standard when lesions are near the eyes.
Your eight-month-old has had eczema since she was three months old. Cheeks, creases, the usual. You have a good routine — daily baths, CeraVe cream within three minutes, occasional hydrocortisone when it flares. It is under control. Not gone, but managed.
Your mother-in-law comes to visit. She kisses the baby on the cheek — both cheeks, multiple times, because she missed her. You did not notice the small sore in the corner of her lip. She did not think anything of it — she gets cold sores all the time.
Four days later, your baby's left cheek — her worst eczema side — looks wrong. Not the usual dry, rough patches. There are clusters of tiny blisters you have never seen before. Some have already broken open, leaving small, round, raw spots that look like they were stamped into the skin. Your baby screams when you try to put moisturizer on. She has a fever of 102.
You almost reach for the hydrocortisone, because your brain says "bad eczema flare." But something stops you. This does not look like eczema. It looks different. It hurts her instead of itching. She has a fever, which eczema does not cause.
You go to the ER. The doctor takes one look and says "eczema herpeticum." Your baby is admitted, an IV is placed, and acyclovir is started within the hour. Over the next three days, the lesions stop spreading. By day five, they are crusting over. By day seven, you go home with oral acyclovir and a follow-up plan.
The conversation with your mother-in-law is hard. But now everyone in the family knows the rule: no kissing the baby during a cold sore. Not negotiable. Not ever.
Your baby recovers fully. You go back to your eczema routine, without steroids at first, then reintroduce them carefully under your dermatologist's guidance. You keep oral acyclovir in the medicine cabinet for the future, just in case. You take photos of what normal eczema looks like on your daughter's skin, so you will spot the difference instantly if it ever happens again.
You know what to look for now. That is the whole point of this guide.
This guide is for informational purposes only and is NOT a substitute for professional medical advice. Eczema herpeticum is a medical emergency. If you suspect your baby has eczema herpeticum — clusters of painful blisters on eczema skin, especially with fever — go to the emergency room immediately. Do not wait for a pediatrician appointment. Do not apply topical steroids. Get emergency medical care now.
