Follow-up appointment for Addy

Addison still has the same ear infection from 2 weeks ago along with some congestion & of course the pneumonia.  The pedi doesn't think the rash is from any type of medication & believes that it's hives (urticaria) from the viral infection in her lungs.  How do you know who's right?  ER doctors or pediatrician?  I'm leaning towards the pedi since babies are her specialty!  She prescribed Singulair for the hives/allergies & Zithromax for the ear infection & chest congestion.  Our poor little baby!  She's had such a rough time the last couple of weeks.  I'm praying the worst is behind us now.  We go back for a follow-up in 2 weeks & should be able to do the well-visit then also.