Unknown Rash on 10 month old's arm

Dear Dr.,
My 10 month old son developed a rash on the back of his right arm/shoulder a few weeks ago.  It has stayed constant (not gotten larger or spread).  It does not appear to be itchy.  It does not appear dry.  It is flesh color/reddish... raised bumps, almost blending together.  I would say it is 'waxy'.  

The pediatrician told us to try cortisone 1% twice a day.  She also referred us to the dermatologist, but there is a 3 month waiting list to get an appointment!  I'm concerned that this may be something that needs immediate attention!

I will try to post 2 pictures of it here...
[IMG]http://i123.photobucket.com/albums/o288/jennym412/IMG_2469.jpg[/IMG]
[IMG]http://i123.photobucket.com/albums/o288/jennym412/IMG_2512.jpg[/IMG]

If you can't see the pictures, please try these links...
http://i123.photobucket.com/albums/o288/jennym412/IMG_2469.jpg
http://i123.photobucket.com/albums/o288/jennym412/IMG_2512.jpg

It would be great if we could get your opinion on what you think this is.  It doesnt seem like eczema to me.  It is only in this one spot.  I'm concerned it could be an infection of some sort.  It does not appear to have any open wound type areas.  I dont see any 'white heads' or anything like that...

Please help!  We appreciate it!  We won't be able to see a dermatologist until February!!!
Thanks!

ps - i did my undergrad at Tufts...