I have re occurring sores on my arms that don t heal. They start out as small white bump under the skin & if you break them they turn into open sores that grow in size. they get a thick itchy scab on them. They are almost like an infected hair follicle , this is also true if the skin get broken from small cut. It is beginning to happen on my face now. the same sores will continue to partially heal then reappear. They leave a dark scar when they finally do heal & may come back with no aggravation.