These are my essentials for daily living. Keys, wallet, phone, and, yes, handkerchief.
I suffer from a potpourri of things that make my head explode in a sneezing fit. I might get up and breathe clearly, only at the store to stand next to someone covered in pet dander and erupt.
Having a handkerchief tucked in my back pocket is cheap insurance that whatever weird, exotic or troublesome allergens come my way I have a quick, reliable, socially acceptable way to handle it.
In those rare moments when a sneeze comes too quickly for even a quick-draw to the back pocket, my move of extreme unction is the vampire sneeze –sneezing downward while bringing the crook of my arm to my nose.