When you live with eczema, you probably already know the pattern: you catch a cold, fight off a bug, or deal with a viral infection, and just as you think you’re recovering, your skin suddenly erupts into a flare. Redness, itching, swelling, oozing the works. It can feel like your body is attacking you from all angles. And if you’ve ever wondered why your skin seems to “punish” you after you’ve been unwell, let me reassure you there’s a real biological reason behind it.
In this guide, I’m going to walk you through exactly why infections trigger eczema flares, why some people are more vulnerable than others, and what you can do to calm things down quickly and prevent complications. I’ll also share the dermatologist-recommended treatments that make the biggest difference, plus the signs that tell you when it’s time to get medical help. Let’s dive in and by the end, you’ll understand your skin better than ever.
Why Eczema Flares After Infections: What’s Really Happening?
Before we get into the mechanics of infection-related flares, it helps to understand that your immune system and skin barrier are deeply connected. If your body is busy fighting an infection, your skin’s natural resilience is affected and because eczema is essentially a barrier and inflammation disorder, that dip in resilience can spark chaos.
There are several reasons why infections lead to eczema flares, and they often overlap. Here’s what’s going on beneath the surface
1. Your Immune System Diverts Resources Away From the Skin
When you’re fighting a viral or bacterial infection, your immune system goes into defence mode. Your body starts prioritising fighting off the invading pathogen, and in the process, it temporarily shifts your immune activity away from its usual housekeeping tasks including maintaining your skin barrier.
Because eczema already involves a weakened skin barrier, that extra dip makes your skin more reactive, drier and less able to defend itself. In other words, your immune system is doing such a good job battling your infection that it accidentally leaves your skin vulnerable.
2. Inflammation Surges During and After Illness
Your immune system uses inflammation as a defence mechanism. During infections, inflammatory molecules flood your body to help fight off the virus or bacteria. But afterwards even when you feel better your inflammatory signalling can remain heightened for days or weeks.
If you’re prone to eczema, this extra surge of inflammation often shows up in your skin as:
- Redness
- Hot patches
- Increased itchiness
- Raw, cracked areas
- Weeping or crusting
Think of it like a fire alarm that keeps going off even after the fire is out. Your immune system is acting in good faith, but your skin pays the price.
3. Fever, Sweating and Dehydration Dry Out the Skin
You know how fever makes you sweat more? That sweating leads to water loss, salt loss, and changes in your skin’s natural pH. Add dehydration from illness, and your skin barrier becomes even more compromised.
Dry skin equals itchy skin. Itchy skin equals scratching. Scratching leads to skin damage and you guessed it a flare.
4. Viral and Bacterial Toxins Can Directly Irritate the Skin
Some viruses (like the common cold or flu) and bacteria release toxins that circulate in the bloodstream. For those with eczema, these immune-system-triggering toxins can worsen inflammation or provoke new patches of dermatitis.
It’s not that the virus is directly in the skin more that the immune system is reacting so strongly to the infection that your skin becomes collateral damage.
5. Changes in Routine During Illness Make Flares More Likely
Let’s be honest: when you’re sick, your skincare habits might slip. You may:
- Skip moisturising
- Stay in bed longer with warm bedding
- Take more hot showers
- Use more tissues around your nose
- Eat less nutritiously
- Forget your prescribed treatments
None of this is your fault you’re unwell. But each of these small disruptions can weaken your skin barrier when it’s already under extra strain.
6. Some Infections Directly Involve the Skin
Certain viral and bacterial infections don’t just cause a general immune response they affect the skin directly, which can make eczema flares unavoidable. Examples include:
- Herpes simplex virus, leading to eczema herpeticum
- Staphylococcus aureus, one of the most common bacteria responsible for infected eczema
- Streptococcal infections, which can contribute to cellulitis or impetigo
If you’ve ever had a flare that felt different hotter, more painful, more swollen, or producing yellow crust you may have experienced this.We’ll get into the signs of those complications later.
Types of Infections That Commonly Trigger Eczema Flares
You might be surprised to learn just how many common illnesses can lead to a sudden worsening of eczema symptoms. Here are the infections most frequently linked with flares:
1. Viral Respiratory Infections (Colds and Flu)
For many people with eczema, a cold or flu is the number-one flare trigger after stress. The inflammation, fever and dehydration combine into a perfect storm.
2. COVID-19
Many people report worsening eczema during or after a COVID-19 infection. Even mild COVID can create prolonged inflammation and disrupt immune signalling, setting off post-infection dermatitis.
3. Gastrointestinal Bugs
Vomiting and diarrhoea can lead to dehydration, and inflammation from the gut often affects the skin. The gut-skin connection is real.
4. Bacterial Infections (especially Staph and Strep)
Staphylococcus aureus is notorious for colonising eczema-prone skin. When your body is weakened from another illness, staph bacteria can multiply rapidly, causing:
- Increased redness
- Crusting
- Oozing
- Pain
- Sudden worsening of itch
Streptococcal infections can have a similar effect, especially around broken or cracked skin.
5. Herpes Simplex Virus (Cold Sores)
If you’ve ever developed clusters of painful, blister-like spots during a flare, you may have had eczema herpeticum, a serious complication caused by the herpes virus spreading within eczematous skin. It can be dangerous if untreated.
I’ll explain the warning signs later.
6. Ear, Nose and Throat Infections
These often don’t cause fever or intense symptoms, but the immune response alone is enough to provoke a flare.
Who Is Most at Risk of Post-Infection Eczema Flares?
Although anyone with eczema can experience infection-triggered flares, certain groups are more vulnerable.
1. People with Severe or Widespread Eczema
If your skin barrier is already compromised over large areas, infections hit harder and flares tend to be more intense.
2. Children
Children’s immune systems are still developing, and their skin barrier is naturally thinner and more porous. They are also exposed to more viruses in school or nursery settings.
3. Adults with Atopic History
If you have asthma, allergies or hay fever as well as eczema (the “atopic triad”), you’re more likely to experience immune overactivation after illness.
4. People Prone to Skin Infections
Frequent staph or strep colonisation increases the risk of complications after viral or bacterial illnesses.
5. Those with Vitamin D Deficiency or Poor Sleep
Both vitamin D levels and quality sleep influence immune function and skin barrier repair. When either is low, post-infection flares become more likely.
Symptoms of Post-Infection Eczema Flares
You know what your eczema feels like normally. A flare after an illness, however, often looks and feels more aggressive, fast-moving and stubborn. You might notice:
- Sudden redness or rash spreading across new areas
- Intense itching within hours
- Hot, inflamed patches
- Cracked or split skin
- Increased dryness
- Blistering or weeping
- Yellow or honey-coloured crusts (infection warning sign)
- Swelling around patches
- Feeling feverish even after the main illness has passed
- Skin pain rather than itching (often infection-related)
If your skin feels much worse than usual or symptoms escalate quickly, it’s wise to monitor closely for signs of complications.
When a Post-Infection Flare Means Something More Serious
Certain complications require urgent medical treatment. These are the red flags to watch for.
1. Eczema Herpeticum (Herpes Infection of Eczematous Skin)
This is a dermatology emergency.
Look out for:
- Crops of small, dome-shaped blisters
- Severe pain rather than itching
- Fever, chills or fatigue
- Rapid spreading across the face or body
- Punched-out erosions (small, round pits within the skin)
If you ever suspect this, seek urgent medical care. Antiviral tablets (usually aciclovir) dramatically improve outcomes when started early.
2. Bacterial Infection (Impetigo or Cellulitis)
Signs include:
- Yellow crusts
- Oozing patches
- Warmth and swelling
- Increasing redness
- Pain
- Pus
- Fever that returns after your original infection improves
Bacterial infections require antibiotics topical or oral depending on severity.
3. Widespread or Severe Flare That Stops You Sleeping or Functioning
If you’re unable to sleep, work or even wear clothing comfortably, it’s time for professional help.
A dermatologist can manage severe flares far more effectively than over-the-counter treatments alone.
How to Treat Eczema Flares After Illness
Now let’s get into what you really want to know: what you can do to calm your skin quickly and prevent the flare from spiralling.
The treatments below are evidence-based, dermatologist-approved and safe for most people with eczema.
1. Rehydrate Your Skin Intensively
After illness, your skin desperately needs moisture. I recommend:
- Applying a rich, fragrance-free emollient at least 3–4 times a day
- Using thicker ointments at night
- Keeping a travel-size moisturiser by your bed, on your desk and in your bag
Focus particularly on:
- Flexures (elbows, behind knees)
- Hands
- Neck
- Around the nose and mouth (where colds irritate most)
Hydration is always the first step, not the last.
2. Use Your Prescribed Topical Steroids Correctly
During a post-infection flare, your skin is inflamed and needs help calming down. If you’ve been prescribed topical corticosteroids, using them in the correct potency and frequency makes a huge difference.
General guidance (though your dermatologist’s advice takes priority):
- Mild eczema: hydrocortisone 1%
- Moderate eczema: moderate-strength steroids
- Severe flares: potent steroids for short periods
Apply moisturiser first, wait 5–10 minutes, then apply the steroid.
3. Consider Topical Calcineurin Inhibitors
If steroids don’t work well for you, or certain areas of your skin are sensitive (eyelids, face, neck, groin), your dermatologist may recommend:
- Tacrolimus
- Pimecrolimus
These calm inflammation without steroid side-effects.
4. Use Antihistamines if Itching Is Severe
Antihistamines won’t stop the inflammation itself, but they do help reduce itching especially at night helping you stop scratching irritated skin.
5. Treat Bacterial or Viral Complications Quickly
If there’s any sign of bacterial infection, antibiotics are essential. If eczema herpeticum is suspected, antivirals must be started immediately.
Never try to “wait it out” if your symptoms fall into the danger category.
6. Try Wet Wraps or Damp Dressings
Wet wrapping can be very effective for severe flares, especially in children or after a fever. It helps by:
- Cooling the skin
- Reducing itch
- Enhancing absorption of topical treatments
- Preventing scratching
Ask your dermatologist for guidance if you’re unsure how to apply them safely.
7. Focus on Rest, Hydration and Diet
Your body is still recovering internally. Support this recovery with:
- Plenty of water
- Balanced meals with good fats (olive oil, salmon, avocado)
- Sources of zinc and vitamin D
- Adequate sleep
The healthier your immune system, the faster your skin can repair.
8. Avoid Triggers Until the Flare Settles
This includes:
- Hot showers
- Harsh soaps
- Fragranced products
- Tight clothing
- Wool or synthetic fabrics
- Perfumes or aftershaves
Think of your skin as healing tissue. Give it the gentlest environment possible.
Long-Term Options if You Get Flares After Every Infection
If post-infection flares happen regularly, it may be time to explore longer-term eczema treatments under a dermatologist’s supervision.
These may include:
1. Phototherapy (UVB Treatment)
This uses controlled ultraviolet light to reduce inflammation and strengthen the skin barrier. It’s safe when administered correctly.
2. Systemic Medications
For moderate-to-severe eczema, dermatologists may recommend:
- Oral immunosuppressants
- Biologic injections (such as dupilumab)
- JAK inhibitors (newer medications that target inflammation quickly)
These treatments can dramatically reduce flare frequency and severity.
3. Managing Chronic Staph Colonisation
If your skin repeatedly gets infected after viruses or illnesses, your dermatologist may help you reduce bacterial load through:
- Antiseptic washes
- Bleach baths (under medical guidance)
- Targeted antibiotics
This can make a big difference in preventing future flares.
How to Prevent Eczema Flares After Future Infections
You can’t always avoid getting sick, but you can reduce the severity of post-infection flares.
Here’s what I recommend:
1. Moisturise Before Illness Is Fully Over
Don’t wait until you’re back to normal. When you feel 80% better, start moisturising more aggressively.
2. Stay Hydrated During Fever or Sweating
Even small increases in water intake help your skin barrier recover faster.
3. Keep Your Eczema Medications Handy
When you first feel a flare coming, act fast. Don’t wait for it to explode.
4. Protect Your Nose and Mouth Area When Using Tissues
Use a soft, fragrance-free emollient around the nostrils to prevent irritation from constant wiping.
5. Support Your Immune System
You can help prevent both infections and related flares by:
- Sleeping well
- Eating nutrient-dense foods
- Managing stress
- Taking vitamin D supplements if deficient
6. Have a Flare Plan Ready
Your dermatologist can help you create a personalised action plan that tells you:
- What to use
- When to use it
- What signs require medical help
- How long to continue each product
This prevents panic and speeds up recovery.
When You Should See a Dermatologist
If your flares:
- keep happening after illnesses
- don’t respond well to your usual treatments
- interfere with sleep
- cause repeated infections
- affect your confidence or daily life
it’s time to get specialist support.
A dermatologist can help you build a skin-barrier-supporting routine, choose the right treatments and explore advanced therapies if needed. If you’re looking for specialised care, you can find expert help through services offering eczema treatment in London.
FAQs:
1. Can infections really cause eczema flare-ups?
Yes, infections can absolutely trigger eczema flares. When your immune system is busy fighting off a virus or bacteria, your skin barrier becomes more vulnerable. Inflammation rises throughout the body, which often shows up first on sensitive skin. This makes eczema patches redder, itchier and more reactive. Even mild illnesses can overstimulate the immune system and spark a flare.
2. Why does my eczema flare after I recover from a cold?
Post-infection inflammation can linger long after you feel better. Your immune system stays activated for days or weeks, and that can overwhelm eczema-prone skin. Fever, dehydration and sweating during illness also dry out the skin barrier. Once the barrier weakens, flares become much more likely. That’s why many people feel worse after the cold, not during it.
3. Is it normal for eczema to spread to new areas after being sick?
Yes, it’s common for a flare to extend to new areas following an infection. Your skin barrier becomes weaker overall, not just where your eczema normally appears. Heightened inflammation makes the skin more reactive across the body. Add dryness or scratching, and flare-ups can spread quickly. It’s a sign your immune system is still recalibrating.
4. Can COVID-19 make eczema worse?
Many people report flares during or after COVID-19, even with mild cases. The virus triggers strong immune signalling, which increases whole-body inflammation. This extra stress makes eczema more unstable and slow to heal. Recovery can also involve fatigue and dehydration, which your skin feels immediately. Supporting hydration and moisture levels helps shorten these flares.
5. How do I know if my eczema flare is actually infected?
Look for signs such as yellow crusting, oozing, spreading redness or increased pain. Skin that feels unusually warm or tender may also indicate infection. If your fever returns after your illness improved, that’s another red flag. Infected eczema needs medical treatment and won’t settle with moisturisers alone. Always seek help quickly if symptoms escalate fast.
6. Why are children more likely to flare after an infection?
Children naturally have a thinner, more delicate skin barrier. Their immune systems are still developing, so inflammation can spread more easily. Kids also catch viruses more often, especially in nursery or school. All of this makes their eczema more unpredictable during and after illness. Consistent moisturising and gentle care help minimise flare severity.
7. What’s the best way to calm a flare after being sick?
Start by rehydrating the skin with rich, fragrance-free moisturisers several times a day. Use your prescribed topical steroids or calcineurin inhibitors to calm inflammation quickly. Drink plenty of fluids and rest, because your body is still recovering. Avoid hot showers, fragranced products and tight clothing while the flare is active. Early treatment always shortens flare duration.
8. Should I use wet wraps during a post-infection flare?
Wet wraps can be very effective when your skin feels hot, itchy or inflamed. They help cool the skin, boost hydration and improve absorption of topical treatments. This technique can also make it harder to scratch, which protects healing skin. Wet wraps are especially helpful after fever, sweating or dehydration. If you’re unsure how to apply them safely, ask your dermatologist.
9. How can I prevent eczema flares the next time I get sick?
Moisturise more frequently as soon as you feel unwell, not after you recover. Drink extra water during fever or sweating to protect your skin barrier. Keep your eczema treatments nearby so you can act at the first sign of a flare. Protect areas irritated by tissues, such as around the nose and mouth. Supporting sleep, nutrition and stress levels also strengthens immunity.
10. When should I see a dermatologist about post-infection flares?
If your flares keep returning after every illness, it’s worth seeking specialist support. You should also get help if you experience repeated infections, sleep disruption or persistent redness. Dermatologists can offer stronger or long-term treatments that stabilise your skin. They can also help identify hidden triggers or chronic bacterial issues. Early intervention prevents flares becoming harder to manage.
Final Thoughts: Your Path to Calmer Skin
Living with eczema is challenging, and post-infection flares can feel like salt rubbed into a fresh wound. But you’re not imagining it, and you’re certainly not doing anything wrong. These flares happen because your immune system, your skin barrier and your overall health are deeply interconnected. Understanding that pattern gives you back a sense of control. Once you know why these flares appear, you can prepare for them, notice the early warning signs and start the right treatments before things spiral.
You also never have to manage it alone. Dermatologists today have incredibly effective tools from evidence-based topical therapies to advanced biologics that can transform how your skin behaves during and after illness. Your skin is resilient, and with the right care, knowledge and support, you can break the cycle of post-infection flare-ups and live more comfortably, confidently and calmly. If you’re looking for effective eczema treatment in London, reach out to us at the London Dermatology Centre to arrange a consultation with one of our experienced specialists.
Reference:
1. Brunner, P. M., Guttman-Yassky, E. & Leung, D. Y. M. (2017) ‘Molecular mechanisms of atopic dermatitis pathogenesis’, International Journal of Molecular Sciences, 22(8), 4130. Available at: https://www.mdpi.com/1422-0067/22/8/4130
2. Williams, H. C. et al. (2019) ‘The role of bacterial skin infections in atopic dermatitis: expert statement and review from the International Eczema Council Skin Infection Group’, British Journal of Dermatology, 182(6), 1331–1345. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC7317931
3. Boguniewicz, M., Leung, D. Y. M. (2016) ‘Bacterial and viral infections in atopic dermatitis: immunologic and molecular mechanisms’, Journal of Allergy and Clinical Immunology, (comprehensive review). Available at: https://pubmed.ncbi.nlm.nih.gov/27377298/ PubMed
4. Wang, Z., et al. (2024) ‘Understanding the role of Staphylococcus aureus in atopic dermatitis’, open-access on. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC11608963
5. Sroka-Tomaszewska, J. & Trzeciak, M. (2021) ‘Molecular Mechanisms of Atopic Dermatitis Pathogenesis’, International Journal of Molecular Sciences, 22(8), 4130. Available at: https://www.mdpi.com/1422-0067/22/8/4130