Eczema (Atopic Dermatitis)
A barrier disease — and the fear of steroids is doing more harm than the steroids
What it is
Atopic dermatitis is a chronic, relapsing, inflammatory skin disease characterised by intense itch, dry skin, and recurrent flares of red, inflamed, sometimes weeping eczema. It arises from a genuine defect in the skin barrier — including, in many people, mutations in the filaggrin gene — combined with immune activation. Water escapes and irritants and allergens get in.
Why it matters
Eczema is a barrier disease, and this is one of the few places in medicine where the 'leaky barrier' story is actually true — unlike the 'leaky gut' marketed to people with digestive symptoms. What makes eczema worth a page of its own is the treatment gap: the most common problem in eczema care is not steroid overuse but steroid UNDER-use. Fear of topical corticosteroids is widespread, documented, and leads directly to under-treated inflammation, more flares, worse sleep, and more infection — harm caused by avoiding a treatment rather than by taking it.
What BioSignal knows about treating this
What works for Eczema (Atopic Dermatitis)
BioSignal’s clinical summary, most important first.
- Emollients — the cornerstone, applied liberally and constantly, flare or no flare
- Topical corticosteroids — the mainstay of flare treatment. Use them properly rather than fearfully
- Topical calcineurin inhibitors and crisaborole — steroid-sparing options, useful on the face
- Avoiding irritants: soap, fragrance, hot water, wool
- Dupilumab and JAK inhibitors — genuinely transformative for moderate-to-severe disease
- Treating infection when present (weeping, crusting, sudden worsening)
Signal Records relevant to this condition
Interventions and contributing factors — some of these records describe a cause rather than a cure. The rating shown is BioSignal’s confidence in that Signal Record, not a claim about how well it treats this condition. Open any of them for the full evidence.
- RetinoidsHigh confidence
The best-evidenced topical in dermatology, for acne and for photoaging — and among the cheapest. Retinol is not tretinoin. Expect irritation for a few weeks. Isotretinoin is a potent teratogen; the depression and IBD links are not established.
- ProbioticsLimited evidence
Specific strains help specific conditions. 'Probiotics for gut health' in healthy adults is not supported — fibre has the better evidence.
- Vitamin DHigh confidence
Effective for deficiency and for bone health in at-risk groups. For broad disease prevention in adults who are already replete, the largest trials are null — and confidence in that null is high. Routine testing of healthy adults is not supported.
- Omega-3 Fatty AcidsModerate confidence
Lowers triglycerides, and reduces preterm birth in pregnancy. Routine fish oil does NOT prevent cardiovascular disease, cancer or dementia in the general population. High-dose omega-3 increases atrial fibrillation risk — a real harm most bottles do not mention.
New to this? Read these first
How this usually unfolds
- Recognize risk factors
- Get diagnosed
- Track key biomarkers
- Lifestyle first
- Evidence-based treatment
- Long-term monitoring
Who is at risk
- Family or personal history of eczema, asthma, or hay fever (the atopic march)
- Filaggrin gene mutations — a genuine barrier defect
- Early-life environment and irritant exposure
- Soaps, detergents, fragrance, and hot water
- Dry, cold climates and low humidity
- Stress and poor sleep (which the itch also causes — a loop)
How it's diagnosed
Eczema is a clinical diagnosis based on the pattern, chronicity, itch, and personal or family history of atopy. Allergy testing is NOT routinely required and is a common source of harm: incidental positive tests lead to unnecessary food elimination, which does not improve the eczema and can increase the risk of developing a true food allergy.
Key biomarkers
Biomarker pages for this condition are on the roadmap.
Lifestyle
Explore this condition across BioSignal
Related Foundations
Related Signal Records
Related conditions
Frequently asked questions
Are topical steroids dangerous?
Used properly, for flares, in the right strength for the site, they are safe and they are the mainstay of treatment — and the fear of them is now causing more harm than the drugs are. This is well documented: topical corticosteroid phobia leads people to use too little, too briefly, and too late, which means inflammation stays active, flares last longer, sleep suffers, and skin infections become more likely. Skin thinning is a real effect of prolonged high-potency use on delicate sites, and it is not what happens when a moderate steroid is used properly on a flare and then stopped. The commonest error in eczema is not overuse. It is under-use.
Is my eczema caused by a food allergy?
Almost certainly not, and this is where a great deal of harm is done. Food allergy and eczema often occur in the same person because both are atopic — but the food is very rarely driving the eczema, and removing it very rarely clears it. Worse, unnecessary food elimination can INCREASE the risk of developing a genuine food allergy, because avoidance rather than exposure is what sensitises. Do not put yourself or a child on an elimination diet on the strength of a positive test alone. Treat the skin.
What is the single most useful thing I can do?
Moisturise, far more than feels reasonable, every day, whether or not your skin is flaring. Eczema is a defect in the barrier — the skin genuinely leaks water and lets irritants in — and emollients are how you support it. This is unglamorous, it is not what anyone wants to hear, and it is the foundation on which everything else works.
Is 'leaky skin' real? I thought that was pseudoscience.
This is a fair question and the distinction is genuinely interesting. 'Leaky gut syndrome' is not a recognised diagnosis and is used to sell supplements. A leaky SKIN barrier, by contrast, is a well-characterised, gene-linked, measurable defect — filaggrin mutations impair the barrier, water escapes, allergens enter. Same metaphor, entirely different evidential standing. The difference between the two is a good illustration of why BioSignal evaluates each claim on its own evidence rather than by whether it sounds plausible.
Will my child grow out of it?
Many children do improve substantially as they grow, and that is a real and reasonable hope. It is not a reason to under-treat in the meantime: uncontrolled itch damages sleep, learning and mood for the whole family, and scratching drives infection and further inflammation. Treating the disease well now is not in tension with growing out of it later.
Evidence summary
Atopic dermatitis results from skin-barrier dysfunction — including filaggrin loss-of-function mutations — combined with type-2 immune activation. Emollients are established as foundational therapy. Topical corticosteroids have strong evidence for flare treatment and are recommended first-line; topical corticosteroid phobia is a documented phenomenon associated with under-treatment and poorer disease control. Topical calcineurin inhibitors and crisaborole are effective steroid-sparing options. Dupilumab and JAK inhibitors have strong randomised evidence in moderate-to-severe disease. Routine food-allergy testing and elimination diets are not supported for eczema management, and unnecessary avoidance may increase the risk of developing IgE-mediated food allergy. Evidence for probiotics in treating established eczema is weak and inconsistent.
References & sources
- American Academy of Dermatology guidelines for the management of atopic dermatitis
- NICE guideline: Atopic eczema in under 12s
- Literature on topical corticosteroid phobia and treatment adherence
Educational information — not medical advice
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