Neighborhood Environmental Exposures and Immune-Mediated Skin Diseases

Conclusions

• Neighborhood and environmental exposures appear to meaningfully influence the risk and severity of many immune-mediated skin diseases, not just skin cancer or photoaging.
• Air pollution is one of the most consistently harmful exposures, with evidence linking particulate matter and nitrogen dioxide to worse atopic dermatitis, psoriasis, and systemic autoimmune disease.
• Climate factors matter in a disease-specific way, with cold, extreme heat, humidity, snowfall, and other weather variables affecting skin disease risk and flares.
• Barrier disruption, oxidative stress, immune dysregulation, microbiome changes, circadian disruption, and neuroendocrine stress are likely shared biological pathways connecting environment to skin disease.
• Prenatal and early-life exposures can increase later childhood risk, suggesting that timing of exposure is critical.
• Neighborhood context such as deprivation, safety, social cohesion, and access to healthy resources can worsen dermatologic outcomes, especially severity.
• Greenness and rural living generally appear protective, likely through pollution reduction, cooling, and support of healthier environments.
• Artificial light at night and noise likely contribute harm through circadian and stress-related mechanisms.
• Hard water is associated with worse atopic dermatitis and may also contribute to other inflammatory skin conditions.
• Environmental effects are often stronger in vulnerable populations and in people with genetic predisposition, showing important gene-environment interaction.
• Machine-learning models using neighborhood and individual-level variables can explain a substantial portion of disease variation, but a meaningful fraction remains unexplained.
• For atopic dermatitis, the evidence base is strongest, while for other eczemas, acne, hidradenitis suppurativa, psoriasis, and autoimmune disease the evidence is emerging but increasingly consistent.
• Systemic sclerosis and lupus show geographic clustering near industrial and traffic-related exposures, supporting the possibility of local environmental triggers.
• Industrial emissions, solvents, heavy metals, and traffic proximity may be particularly important for systemic autoimmune rheumatic diseases.
• The overall message is that environmental prevention and counseling should become part of dermatologic care, alongside traditional disease management.