ADHD and inflammation

Dear friends, I struggle with how sick my ADD family is. We all seem ridiculously prone to colds, but I was never like this growing up or when I lived alone. I believe ADHD is somehow linked to inflammation. Is there a connection? 

I found a diary note from February 9, which said at least one child had then been home sick every day since New year's. We had also all been ill for a week over Christmas. And now it's the same, at least one, more often two or three, have been at any one time down with flu-like symptoms the last month. 

They said children stop getting difficult colds after the first couple of years. Mine are now in middle to high school and nothing has improved.

I try to arrange family gatherings in the winter months, but have to cancel so often it seems unlikely we'll have Christmas with relatives and I'm hoping for a birthday party later, but hesitate to send out invitations.

I was seldom ill before. I link my own sick days to the stress of living with ADHD. 

Does anyone recognize this? Is there a connection between ADHD and banal infections?