Suggest Remedy For Itchiness & Scabs On Toe Knuckles

Hi. For the last couple of years I have had itchy toe knuckles and have scab like formations on them. My dermatologist told me that it was not athletes foot or fungy and when I took pills for two months for athletes foot in my toe nail the knuckle problem did not go away (confirming what my dermatologist said). What is it and how can I get rid it?