Yes, scratching is the most common cause of secondary skin infections in people with eczema and psoriasis. When you scratch, you create microscopic tears and portals of entry in the skin barrier. Because the skin in these conditions is already compromised and often lacks certain antimicrobial proteins, it becomes an ideal breeding ground for bacteria, viruses, and fungi. In the UK, the NHS warns that infected eczema (particularly Staphylococcus aureus) is one of the most frequent reasons for hospital admissions related to skin disease. Understanding the signs of infection and the dangers of the itch-scratch cycle is essential for preventing serious complications.
What We’ll Discuss in This Article
- The Itch-Scratch-Infection cycle: How scratching breaks the barrier.
- Bacterial Infections: Identifying Staph (Impetigo) and Strep.
- Viral Infections: The danger of Eczema Herpeticum.
- Fungal Infections: Why yeast thrives in psoriasis plaques.
- Warning Signs: When to seek urgent medical advice.
- Prevention: How to protect the skin and reduce the urge to scratch.
1. How scratching invites infection
The skin serves as a physical and chemical shield. In eczema and psoriasis, this shield is already leaky. Scratching acts as a mechanical trauma that:
- Strips the Stratum Corneum: Removes the protective top layer of skin cells.
- Increases Inflammation: Triggers the release of more histamines, which makes the skin itch even more.
- Transfers Pathogens: Moves bacteria from under the fingernails directly into the open wounds.
2. Common Bacterial Infections
The most frequent complication is a bacterial infection, usually caused by Staphylococcus aureus or Streptococcus.
- Impetigo: This often appears as honey-coloured crusts on top of an eczema patch. The skin may feel hot, look increasingly red, and begin to weep fluid.
- Cellulitis: If the bacteria penetrate deeper into the skin layers, it can cause cellulitis, a serious infection where the skin becomes swollen, painful, and very red. This often requires systemic antibiotics.
3. The Viral Threat: Eczema Herpeticum
For those with atopic eczema, the most dangerous infection is Eczema Herpeticum, caused by the cold sore virus (Herpes Simplex).
- Appearance: It manifests as clusters of small, painful, punched-out blisters that can spread rapidly across the face and body.
- Urgency: This is a medical emergency. If left untreated, it can spread to the eyes or lead to systemic illness. If you see these specific blisters, contact 111 or your GP immediately.
4. Fungal and Yeast Infections
Psoriasis, especially in skin folds (inverse psoriasis), is particularly prone to yeast infections like Candida. The warm, moist environment of a psoriasis plaque, combined with the skin damage from scratching, allows yeast to thrive, causing a shiny red appearance and a different type of intense burning itch.
5. When to seek medical advice
In the UK, you should consult a healthcare professional if your skin condition changes in the following ways:
- Weeping or Crusting: Fluid or pus oozing from the skin.
- Golden/Yellow Crusts: A classic sign of bacterial impetigo.
- Increased Pain: If a normal itch turns into a throbbing or burning pain.
- Fever or Shivers: Signs that the infection has become systemic.
- Rapid Spreading: Redness that expands quickly or streaks moving away from the site.
6. Prevention and Safe Scratching
Breaking the cycle is the best way to prevent infection:
- Keep Nails Short: Minimises the trauma caused by unconscious scratching.
- The Tap Technique: Instead of using nails, try firmly tapping or patting the itchy area with the pads of your fingers.
- Cotton Gloves at Night: Prevents damage from scratching while you sleep.
- Use Antiseptic Washes: If you are prone to infections, a GP may prescribe an antimicrobial wash (like Dermol 500) to lower the bacterial load on your skin.
Conclusion
While the urge to scratch can be overwhelming, it is the primary gateway for infections that can turn a manageable skin condition into a serious medical issue. By recognizing the early signs of bacterial and viral invaders and using safe scratching techniques, you can protect your skin barrier and allow it the time it needs to heal. If you suspect an infection, do not wait; early treatment with the correct antibiotics or antivirals is the key to preventing scarring and further flare-ups.
Can I put steroid cream on an infected patch?
No. Steroids suppress the immune response. If you apply them to an active infection, they can act as fuel, allowing the bacteria or virus to spread even faster. Use an antimicrobial cream first.
Does weeping always mean infection?
Not always, but it is a strong indicator. Severe acute eczema can weep clear fluid even without bacteria, but it should always be reviewed by a professional.
Is infected psoriasis common?
It is less common than infected eczema because psoriasis plaques are usually drier, but fissuring (deep cracks) can certainly lead to secondary infections.
Why does my skin smell different when it’s infected?
Bacterial overgrowth (especially Staph) produces a distinct, sometimes musty or sickly sweet odor. This is often a tell-tale sign that you need medical treatment.
Can I catch a skin infection from someone else?
Secondary infections like impetigo are highly contagious. You should not share towels or bedding with someone who has an active skin infection.
How do I clean an open scratch safely?
Use lukewarm water and a soap substitute. Avoid harsh antiseptics like undiluted Dettol or alcohol, which can further damage the skin barrier.
Does bleach bath help prevent infection?
Under strict medical supervision, very dilute bleach baths can help some patients with chronic Staph infections, but this should never be attempted without a specific protocol from your dermatologist.
Authority Snapshot (E-E-A-T Block)
This article examines the clinical risks of secondary infections in inflammatory skin conditions. It is written by the MyPatientAdvice Medical Writing/Research Team and reviewed by Dr. Rebecca Fernandez, a UK-trained physician with experience in dermatology and infectious diseases. All guidance is strictly aligned with the standards provided by the NHS and the British Association of Dermatologists for 2026.
