930 Staphylococcus aureus abundance is reduced in psoriasis compared with atopic dermatitis and does not associate with disease severity

The presence of S. aureus (SA) by skin culture correlates with barrier function (TEWL) and atopic dermatitis (AD) severity. In contrast, SA infections are rare in psoriasis (PS), little is known about whether abundance plays a role PS We utilized highly quantitative measures total bacterial burden measuring femA 16S rRNA qPCR, respectively, from lesional (L) nonlesional (NL) swabs. also quantified live colony counts (CFU/cm2) (L & NL) AD skin. Disease severity was assessed (PASI for or EASI AD). Thirteen (54%F; 38±12yrs; mean±SD) moderate-to-severe (PASI=15±8) were matched race eleven (EASI=15±3) subjects. rCFU (femA qPCR) greater L vs NL (p=0.014) as (p=0.045). positivity rates 38% 15%, compared to 82% 73% sites, respectively) 0% healthy controls (N=11). CFU at 0.8 CFU/cm2 (geometric mean; range:0-5074) 0.1 (range:0-1) PS, while 155.8 (range:0-8000) 20.9 Live significantly (p=0.0027) well (p=0.0007). its counterpart (p=0.0156) similar trend (p=0.0625). (CFU rCFU) did not correlate baseline TEWL disease Although could be cultured more commonly than controls, neither measure reflected integrity. Using these methods, we found markedly higher levels (NL L) L). Our work suggests that subjects’ activity less influenced their hospitable