Try some Camrosa ointment, it works wonders on every animal I've used it on! Just spent 20 minutes this afternoon with my new boar giving him a rub all over with it, soppy sod (him not me!) his skin was really dry looking and bald in places, I'm sure it'll do the trick, he certainly loved the attention.
I also used it on a couple of pigs with lice and it did a great job - they couldn't have ivermectin as they were due to go to slaughter inside the 28 day withdrawal, the bald patches started recovering and it made their coats all shiny, they looked amazing!!!