Hi, my 18 year old son has a sore area at the opening to the ear where your finger might fit. It looks like the skin is swollen there almost blocking the entrance and is very tender to the touch. I hoped it might be a pimple (as he has acne in the face and neck area), but can see no head that might indicate that. He had a mastoidectomy in his other ear 6 years ago...and while the symptoms are unrelated, I am concerned. He is not unwell, no earache, no temperature. Can you tell me what this may be? Thank you.