2 year old Siya was diagnosed with Croup in the past and her mother says she has the same features again, including a hoarse voice. You proceed to examine her and note there is no sternal or intercostal recession at rest, and she is haemodynamically stable. A barking cough is also heard.
You explain that you feel she has mild Croup and prescribe a single stat dose of oral Dexamethasone. What dose should you prescribe?