How long does it take to work? I got a bee sting a couple of days ago. It resolved over 12 hours or so but in the middle of last night it became very itchy. This morning it has swollen bigger than the initial reaction and it is hard to walk on it (its on the sole of my foot). I've taken clarityn and drawn a circle round it. I'm wondering how long to leave it before I try and get to a gp somehow.