Common loss-of-function variants of the epidermal barrier protein filaggrin are a major predisposing factor for atopic dermatitis.
Palmer CN, Irvine AD, Terron-Kwiatkowski A, et al. Common loss-of-function variants of the epidermal barrier protein filaggrin are a major predisposing factor for atopic dermatitis. Nat Genet 2006;38(4):441-6.
Study type: Human genetics · Added to this library August 23, 2026
What the researchers did
The discovery that filaggrin gene mutations underlie a large share of eczema.
What they found
Loss-of-function filaggrin variants, carried by ~9% of Europeans, are a major independent risk factor for eczema.
Why it matters
Some eczema is constitutional — built in before birth. TCM's "Fetal Toxin" category said the same thing without a genome: the child arrived with it.
Relates to the patterns: Blood Deficiency / Wind-Dryness · Fetal Toxin
This summary is educational and does not replace care from your child's pediatrician. Evidence tiers matter: a finding in cells or animals is a reason a treatment could work, not proof that it does.
More in AD biology
Progressive activation of TH2/TH22 cytokines and selective epidermal proteins characterizes acute and chronic atopic dermatitis.
Gittler JK, Shemer A, Suárez-Fariñas M, et al. Progressive activation of TH2/TH22 cytokines and selective epidermal proteins characterizes acute and chronic atopic dermatitis. J Allergy Clin Immunol 2012;130(6):1344-54.
Study type: Human skin-biopsy transcriptomics
What: Sequenced acute vs chronic eczema lesions to see how the disease changes over time.
Found: Acute lesions are Th2/Th22-driven; chronic lesions add Th1 activation and epidermal thickening — the disease shifts state as it ages.
Why it matters: This measured trajectory is the classical pattern sequence — the weeping acute (Damp-Heat) lesion maturing into the dry, thickened chronic (Blood-Deficiency/Wind-Dryness) one. Two vocabularies, one timeline.
Early-onset pediatric atopic dermatitis is TH2 but also TH17 polarized in skin.
Esaki H, Brunner PM, Renert-Yuval Y, et al. Early-onset pediatric atopic dermatitis is TH2 but also TH17 polarized in skin. J Allergy Clin Immunol 2016;138(6):1639-1651.
Study type: Human skin-biopsy study (infants/children vs adults)
What: How baby eczema differs immunologically from adult eczema.
Found: Pediatric eczema shows Th2 plus Th17 activation with barrier/lipid defects dominant — a different disease profile from chronic adult eczema.
Why it matters: Pediatric TCM has always treated infant eczema as its own pattern class (Spleen-centred, supply-side); the transcriptome agrees that babies are not small adults.
The Asian atopic dermatitis phenotype combines features of atopic dermatitis and psoriasis with increased TH17 polarization.
Noda S, Suárez-Fariñas M, Ungar B, et al. The Asian atopic dermatitis phenotype combines features of atopic dermatitis and psoriasis with increased TH17 polarization. J Allergy Clin Immunol 2015;136(5):1254-64.
Study type: Human comparative biopsy study
What: Compared eczema biology across Asian and European-American patients.
Found: Asian eczema is more IL-17-driven and "psoriasiform" — thicker, scalier, sharper-bordered — despite similar Th2 levels.
Why it matters: Eczema differs by population as well as by person. It also explains why an IL-17-suppressing ointment (indigo) earns its keep on the sharply bordered plaque.
Intrinsic atopic dermatitis shows similar TH2 and higher TH17 immune activation compared with extrinsic atopic dermatitis.
Suárez-Fariñas M, Dhingra N, Gittler J, et al. Intrinsic atopic dermatitis shows similar TH2 and higher TH17 immune activation compared with extrinsic atopic dermatitis. J Allergy Clin Immunol 2013;132(2):361-70.
Study type: Human biopsy study
What: The ~20% of eczema patients with normal IgE ("intrinsic" eczema), profiled.
Found: Same Th2 activation but higher Th17/Th22 — a distinct endotype hiding under one diagnosis.
Why it matters: More evidence that "eczema" is several diseases — which is precisely what pattern differentiation has always claimed.