Atopic Dermatitis
ICD-11: EA80
Disease Overview
Atopic dermatitis (eczema) is a chronic inflammatory skin disease characterized by pruritus, erythema, and barrier dysfunction. It is a component of the atopic march (often preceding asthma and allergic rhinitis). Th2 skewing, filaggrin (FLG) deficiency, and epithelial barrier defects are central. Heritability ~75%; SNP-based h² ~0.15. Key genes include FLG (loss-of-function), IL4/IL13 (Th2), and TSLP. Allergens, irritants, climate, and stress trigger flares; microbiome and diet may modify risk.
Often begins in infancy/childhood; can persist or onset in adolescence. Psychosocial burden and transition to adult care are relevant.
Genetic Architecture Summary
| Gene | Variant | GWAS p | Evidence | Strength |
|---|---|---|---|---|
| FLG | loss-of-function | 1.0e-50 | Filaggrin; barrier protein; null alleles strongly increase risk | 0.95 |
| IL13 | rs20541 | 1.0e-20 | Th2 cytokine; type 2 inflammation | 0.85 |
Heritability
h² SNP: 0.15 — Eczema GWAS (2020)
PRS notes: FLG status and PRS inform severity; transferability across ancestries variable.
Exposure Modifier Panel
| Exposure | Direction | Strength | Confidence | Mechanism hypothesis |
|---|---|---|---|---|
| air-pollution | amplify | 0.6 | MEDIUM | — |
| psychosocial-stress | amplify | 0.7 | HIGH | — |
| endotoxin | buffer | 0.5 | LOW | Early-life microbial exposure may protect |
Population Equity Notes
GWAS ancestry breakdown: European-dominated; FLG effects vary by ancestry.
Transferability notes: FLG and IL13 replicate; PRS performance in non-European populations limited.
Data gaps: Multi-ancestry GWAS; G×E for allergens and microbiome.
Tissue Context
Visualizations
Risk Shift by Exposure Stratum
Population-level data only — does not predict individual risk
Tissue Relevance
References
- 1.Paternoster L, et al. (2015). Multi-ancestry genome-wide association study of 21,000 cases and 95,000 controls identifies new risk loci for atopic dermatitis. Nature Genetics. doi:10.1038/ng.3424
- 2.Kantor R, Silverberg JI (2016). Environmental and lifestyle factors in atopic dermatitis. Clinical Reviews in Allergy & Immunology. doi:10.1007/s12016-016-8548-5