My first male veild developed something similay on its dorsal crest looked like shed to start and once the shed was gone his spikes were half the size, he went to the vet was priscribed baytril and a anti fungus cream, they did cultures but nothing came out of them so i never found out if they were fungal or bacterial. Today im pretty sure it was a fungal issues but cant be sure. He did heal up nice never again had that issue again with him or others but he was scared from it. you might want to get a vet to check it to make sure its not fungal. Im in canada so prices may be off but my bill was around 100. first visit was 60 the meds in total for baytril and the cream were no more then 20 ish, the rest was the cultures i had done. might be cheaper in the US