Having Swollen Post Auricular Node, Grows In Cold, Had Otitis. What Could It Be?

hello I m a male and I am 23 yo, I have a swollen post auricular node at my left ear for over 7 years ... it is 1cm big ... it slidely grows when I have a cold or something but never more than 1,5 cm, it doesn t hurt when I touch, I had problems with my ears when I was very young, had otitis but in the last 5 years my ears never hurt ... the problem is that the node is always swollen it never disappear ... why is that? what could it be? thank you