In the initial few days, your child may show common flu-like symptoms like clogged or runny nose and mild cough. Around the fourth to fifth day, the following symptoms of bronchiolitis may develop and worsen: Rapid breathing Noisy breathing with a wheezing sound Difficulty eating or drinking Difficulty breathing Irritability and fever Your child may continue to feel sick for up to 10 days. As they recover, the cough can continue to persist for up to 4 weeks.