Hello girls. My baby is two years old and has croup. For six days now …

Hello girls. My baby is two years old and has croup. For six days now he has a fever, for the last two days he's been lethargic, and for the last two days he's had a rash. The doctor was called to the house, they checked, confirmed croup, we did PCR tests on the second day of the fever. He has a fever, cough, runny nose, frequent bowel movements. But for the last two days he's been weak, should it be like that?