Differential Diagnosis for Rhonchi in a 12-month-old

• Single most likely diagnosis
  • Bronchiolitis: This is the most common cause of rhonchi in infants, typically caused by respiratory syncytial virus (RSV). The age of the child and the presence of rhonchi make this a highly likely diagnosis.
• Other Likely diagnoses
  • Asthma: Although less common in infants, asthma can present with wheezing or rhonchi, especially if there's a family history of asthma or allergies.
  • Viral croup: This condition can cause rhonchi, especially if accompanied by a barking cough and hoarseness.
  • Reactive airway disease: Similar to asthma, this can cause rhonchi in response to various triggers.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Epiglottitis: Although rare, this condition is life-threatening and requires immediate attention. Symptoms can include stridor, drooling, and difficulty breathing.
  • Foreign body aspiration: This is a medical emergency that can cause sudden onset of rhonchi, coughing, or choking.
  • Congenital heart disease: Certain heart defects can cause respiratory symptoms, including rhonchi, due to increased pulmonary blood flow or congestion.
• Rare diagnoses
  • Cystic fibrosis: A genetic disorder that can cause chronic respiratory symptoms, including rhonchi, due to thickened mucus production.
  • Primary ciliary dyskinesia: A rare genetic disorder affecting the cilia in the respiratory tract, leading to chronic respiratory infections and symptoms like rhonchi.
  • Vascular rings or slings: Rare congenital anomalies of the aortic arch that can cause respiratory symptoms, including rhonchi, due to compression of the trachea or bronchi.