It would be good if you could take a better picture, but for now it looks like a cricket bite or something to me. I would lower humidity and heighten heat for a little while to help keep bacteria from congregating, and also if you get really worried you can apply Neosporin WITHOUT PAIN RELIEF (pain killer will kill your frog) to stave off infection.
I'm not sure how serious this is, but you should post your temp/humidity and what size tank you have, also what substrate, what plants you're using, and decor, along with what you feed the frog and how often. This will be helpful in further diagnoses.