NGF and Alzheimer disease: We found that exposure to the highly acute TSST reduced the number of detectable NGF+ dermal NF in lesional AD patient's skin along with a decreased PGP 9.5+ NF number and a decreased number of neuro-immune contacts between PGP 9.5+ NF and tryptase+ mast cells in the upper dermis of lesional AD skin (Figure 4), while total mast cell numbers remained relatively stable (not shown).