Elevated total IgE (compared to European AD).Increased infiltration of FcεR1+DCs and Langerhans cellsTh1; Th2; TH17 and Th22 related genes including IL-9 and FoxP3+ Tregs were upregulated in lesional skin compared to non-lesional skin.IL-10; CCL-13; TSLP were exclusively upregulated in African American AD (compared to European American AD). This evidence concerns the gene IL9 and Alzheimer disease.