One Of My Earlobs Had Been Itchy Since Yesterday, And

One of my earlobs had been itchy since yesterday, and this afternoon I have several small blisters along the lower edge of my earlob. I do not think I used any new personal care substances that might cause allergic reaction, and I do not have allergies at all. What could it be? ( I am sorry, I don't have a card to make payment, please cancel)