The most appropriate management is otolaryngology evaluation for possible vocal cord dysfunction. Also known as paradoxical vocal fold motion disorder, this condition is characterized by adduction of the vocal cords (instead of abduction) during inspiration. This is an involuntary maneuver that can occur without other chronic conditions, but it can also happen in patients with asthma. Some patients have episodes related to performance (athletes) or exposure to certain irritants such as smoke or perfume. Symptoms include mid-chest tightness, dyspnea, and lack of symptom relief with asthma treatment. Patients may also note cough and dysphonia, and stridor may be present that may be perceived on examination as an inspiratory monophonic wheeze. The gold standard for diagnosis is observation of vocal cord adduction during inspiration with laryngoscopy after provocation with exercise or irritant exposure. Treatment consists of laryngeal control techniques, biofeedback, and relaxation techniques, usually under the direction of a speech pathologist. Management of other potential conditions that might contribute to vocal cord irritation, such as reflux, sinus disease/allergies, and obstructive sleep apnea, can also be very helpful.

Allergen immunotherapy is not indicated in this patient who has no clinical history of allergy symptoms and has normal findings on his upper airway and nasopharyngeal examinations.

Although the patient is experiencing episodes of shortness of breath, mostly with exertion, there is no additional history or findings on physical examination suggestive of heart disease as the cause of his symptoms. Echocardiography is therefore not indicated.

Stepping up asthma therapy by increasing the intensity of inhaled glucocorticoid therapy is not appropriate because this patient's clinical presentation and spirometry results are not consistent with asthma as the cause of his symptoms.