Croup and possible ear infection Q's

LO started coming down with a cold on Friday.  I almost kept him home from the sitters the other day because she has a 5-year-old in kindergarten this year and a 3-year-old DD.  Both have been sick and the 3-year-old cannot stay out of LO's face.  She is constantly hugging, kissing, hands in his face.  Cute, but not so cute when she's coughing all over him.  Our sitter tries to get her to keep her distance, but as I'm sure you all know, not so easy.  I know LO is bound to get sick, but we've been up a lot the past few nights.  Sat night he was up coughing and sneezing every 1/2 hour to hour.  Last night he was up twice between 11 and 2 then consistently from 2 to 4 and you could hear the change in his cough.  Took him to the pedi today and he has croup (he even has the cough during the day and it has been worse this afternoon) and she said the left ear is red, could be nothing might turn into ear infection so she prescribed steroid and antibiotic.  I'm going to keep him home again tomorrow because I don't want the kids passing the germs back and forth.  I don't know how many days I should keep him home for or how long the cough and sleepless nights will last.  Any experience?