Bald spot under chin

[Holly&Bean]

Hi my Guinea pig has a bald spot under her chin and it’s just appeared in the last few days. It might be the medicine she spit out (cosequin and bactrim for UTI) she won’t let me wipe it off.
Thanks for any help and of the pictures aren’t good enough I’ll try to take more

 

[Holly&Bean]

Also, that yellow-ish looking stuff is some of the cosequin and the bald spot is just a little red, no scabs or flaky skin

 

[WobblyPiggy]

Hi, it could just be off the medication...however of you're concerned or if it has been a recent development ask her vet when she goes back (if she goes back) I know one of my piggies has a bald patch under her chin but its only very small...and the vet has seen it and just said it was normal for her as it is in her crease under her chin...she just doesn't like it touched...

 

[Holly&Bean]

Thanks!