I think that swollen lymph nodes are pretty common when fighting any type of infection or virus, but my main advice is to take your kids to a chiropractor and remove dairy from their diets! Ear infections are not normal and I've seen many kids helped through chiropractic.
Find one who's comfortable with young children and trust me it's gentle and won't hurt them, all kids I know love it! Anything non-invasive or prescribed has to be better for them. Good luck!
P.S. It's a good idea to see your pediatrician always to rule out any serious conditions. But pediatricians don't have any training in chiropractic science and medicine and are therefore unable to say whether or not it's good for a child or to state what it is able to help with, just as a chiropractor or dentist can't prescribe antibiotics, to each his or her own profession!
There is no harm in trying what has worked for so many other people, especially before resorting to antibiotics in a small child.
Just stating what I've seen work numerous times, in addition to having both of my kids adjusted from day one, I've seen ear infections go away once dairy was removed and chiropractic adjustments started. The premise is that the spine houses the nervous system, which controls every aspect of the body. How can someone who hasn't tried it say how or why it works? It just does! And I would try anything that could help my kids be healthier without medical intervention, which I do understand is necessary at times.