Day six, and the swelling is almost totally gone. The scabs are forming a nice, solid crust (sorry if that sounds gross) and I'm sticking to my medication regime.
By now, I'm able to use a mild shampoo mixed with warm water and poured over my head in the bath.
Within another two days, the scabs will fall off (with very gentle persuasion) and I can dispense with the baseball cap in public.
(No sun exposure though, for eight weeks)