Suggest Remedy For Yellowish Scab On The Back Of The Ear

My son has a 'yellowish' scab on the back of R. Ear lobe and some scabbing *minor* bleeding around the cartlidge part of that same ear - is this something I should be concerned about? I've been using a corosone cream on it but doesn't seem to be helping - he's not *overely* bothered by it...what could it be? cancer? maybe he's rubbing his ear at night? Should i see our family doctor?