Dr. Greene’s Answer:
With croup symptoms that show no sign of improvement after 5 days of prelone, it’s time to think of other possible causes — especially with an unidentified something on the chest x-ray.
An inhaled foreign body can cause croup, and would not respond to treatment. Pneumonia could be the cause. Mycoplasma is also possible. Mycoplasma wouldn’t respond to amoxicillin; it would need a different antibiotic.
Croup is typically caused by parainfluenza viruses and is over quickly, but it can also be caused by longer-lasting viruses such as RSV (respiratory syncytial virus), especially in kids with asthma.
In any event, unless the x-ray was read by a pediatric radiologist, I would be in favor of getting a second opinion for your 8-month-old son. The closest children’s hospital would be a good place, and could also direct you to the best place close to you. Most children’s hospitals have a parents’ advice line to get you steered in the right direction.