Generally with PRP for hair loss, patients would certainly experience pain right when the injection is done and will feel some temporary pain within the 24- 48 hours, if you have persistent pain then it could be that some of the sensory nerve of the scab were inadvertently injected. But the good news is that this should resolve within the next several weeks or few months. There is no true treatment for this as it's just an irritated nerve. And these would usually prove and resolve over time, if the pain is very severe you may get some improvement with a prescription medication called Gabapentin I would have you go to your physician to see if you are a candidate for the Gabapentin.