The most appropriate management is to step up therapy for this patient's asthma by adding a low-dose glucocorticoid inhaler. This patient has a history of asthma as a child, which has been quiescent for many years and has not required treatment as an adult. She recently experienced a viral respiratory tract infection with associated wheezing and cough. Viral respiratory infections, most commonly with rhinoviruses, may induce bronchospasm in patients without preexisting reactive airways disease and may require acute treatment for symptom relief. However, viral respiratory infections may also exacerbate underlying asthma and require a step-up in treatment. Although this patient has not required therapy for asthma for many years, she remains persistently symptomatic with evidence of ongoing obstruction beyond the time frame when virally induced bronchospasm in patients without asthma typically resolves, which is usually by 6 to 8 weeks after a respiratory infection. Her symptoms and spirometry results are consistent with mild persistent asthma; therefore, the addition of an inhaled glucocorticoid, consistent with guideline-based treatment recommendations, is indicated to control her asthma.

Because this patient remains symptomatic beyond the time frame in which patients without asthma would be expected to have symptom resolution, continuing either an as-needed or long-acting β₂-agonist would not address the underlying mechanism of obstruction and would not provide optimal control of her asthma. Therefore, neither of these interventions is indicated.

Similarly, discontinuing the inhaler medication would not be appropriate in this patient with asthma who remains symptomatic.