Hi, My Son Is 3 And I Have Always Noticed

Hi, my son is 3 and I have always noticed he has prominent lymph nodes in his neck, from what I have researched online, they are the posterior cervical lymph nodes. In recent months I have been noticing them more - I don't know whether this is because they have grown or just because I've been noticing and have become quite worried about them. The largest one is about 2cm in width. Today I found he has what I think is an outer ear infection. I can see kind of a boil just inside his ear and his ear is very tender there and underneath/behind the ear. Would this affect the posterior cervical nodes, or is it just a coincidence, given that I have been noticing the nodes for weeks? Thanks, I hope you can help.