"Negative Comments"

I attended an appointment with my dermatologist for a review of my eczema and my mum came with me. We entered the room and before we sat down the Dr commented on my mums skin, "You would think I would be seeing you, not you." and laughed. I am sure this was meant as a joke but my mum isn't very confident as it is, and when you have eczema you are quite conscious of how you look anyway and for this to be pointed out makes you feel even worse about yourself. I just feel that the comment was unnecessary and rude.