Adult atopic eczema — dry, itchy, inflamed patches typically on the arms, behind the knees, hands, or neck — flares from a combination of environmental triggers and an underlying immune dysregulation that varies in intensity.
The primary trigger categories:
- Barrier disruption — over-washing, harsh soaps, hot showers, low humidity. Compromises the stratum corneum and lets irritants and allergens in.
- Stress and cortisol dysregulation — chronic stress reliably worsens eczema. Cortisol modulates immune responses and directly affects barrier lipid production.
- Low vitamin D — Umar's review synthesized the evidence linking vitamin D adequacy to eczema severity; supplementation improves severity in trials (Umar, 2018).
- Sleep disruption — poor sleep drives inflammatory cytokines that worsen eczema.
- Specific triggers — dust mites, pet dander, certain foods, fragrances, wool, nickel.
Underlying biology. Eczema is characterized by defects in filaggrin (a barrier protein) and Th2-skewed immune dysregulation. Weidinger's 2018 review provides the most comprehensive current synthesis (Weidinger, 2018). The barrier defect is congenital in many patients; the immune activation is what fluctuates.
What actually helps: ceramide-rich moisturizers, topical corticosteroids or calcineurin inhibitors during flares, dupilumab for severe cases. Manage cortisol, ensure vitamin D adequacy, minimize barrier disruption.
Blood work: vitamin D, hs-CRP, omega-3 index.