When treating a 2-year-old with a barking cough and stridor, what is the most appropriate action?

In a 2-year-old presenting with a barking cough and stridor, the clinical picture is often suggestive of croup, which is typically characterized by these symptoms due to upper airway inflammation. The most appropriate immediate treatment for croup is the administration of an oral corticosteroid, specifically dexamethasone. This medication helps reduce inflammation and swelling in the airway, thereby alleviating symptoms such as stridor and coughing.

Corticosteroids like dexamethasone are effective in managing croup and are recommended due to their ability to improve symptoms and decrease the duration of the illness. The oral route is also appropriate for outpatient management, making it both effective and convenient for use in a young child.

Other treatments listed, such as oral antibiotics like amoxicillin, are not indicated in uncomplicated croup because the condition is viral in nature rather than bacterial. Long-acting beta2-agonists are more relevant in conditions like asthma, which does not align with the primary concerns presented in this case. IV methylprednisolone is typically reserved for more severe cases or when patient management in a hospital setting is required and does not offer the efficiency or convenience of oral administration in this situation.