Rings on my 2 year olds feet

My son does have eczema, but I do not think this is what he has on his feet.  He has these rings on his feet that come and go. Sometime worse that others but you can usually see them.  They are not raised or itchy.  They are just red rings, clear in the middle, all different sizes and they are only on his feet.  They do not bother him.  I mentioned it to the doctor when it started to occur but at that visit they were not noticable.  He said he would not be worried about it, but it has gotten worse.  To the point where they are usually there when I take his socks off at night and they seem to fade by morning.  Like I said before some days are worse that other.  Do you have any idea what this might be?  He has had this for months and even though the doctor said not to worry I am beginning to wonder if I should take him back for a second look.

[Alan Rockoff, MD]

In general, anything that comes and goes can't be anything too serious.  Funguses don't come and go unless you treat them.  Eczema does come and go, but that's scaly.  What you describe sound like hives, perhaps from pressure.  For proper diagnosis, I think your doctor or a dermatologist should see them when they're fresh.  If that's hard to organize, a good-quality photo may help.  

Best.

Dr. Rockoff