advice on horses skin needed!

[goneshowjumping]

when grooming my horse ive noticed what i can only describe as dry patches of hairless skin around the top of his tail area ie. either side of the tail on his bum, there is no hair on these patches which are not huge, but big enough.
he does not seem to be rubbing as his tail is not rubbed, they ahve just appeared!
any thoughts??
sorry to be vague!
havent changed his feed, or washed his rugs in anything so im baffled!
do you think putting some sort of cream on them will help?
i noticed a week ago, and they havent got any bigger, but neither has the hair grown back yet!
he is a 16.1hh, healthy up to weight TB, 6 yrs old.

 

[Izzwizz]

Only thing that comes to mind is ringworm buts that probably an extreme diagnosis. Is he too warm and rubbed because of that? Maybe bathe in warm salt water. Could be lice in his tail so have a really good look there. Hope you get to the bottom of it.

 

[goneshowjumping]

yes, thinking about it, i had rugged him up one night and he was very warm the next day, so that could be it.
its driving me mad not knowing though! no more has appeared so im hoping the hair will grow back.