What is the likely cause of asthma exacerbation in a marathon trainee who has been training for 2 months, recently trained in temperatures less than 10 degrees, and had a sore throat and rhinorrhea 3 days prior?

From the Guidelines

The patient's asthma exacerbation is most likely triggered by an upper respiratory viral infection, as evidenced by the preceding symptoms of sore throat and rhinorrhea that developed three days prior to the exacerbation. This is supported by the fact that viral respiratory infections are among the most common triggers for asthma exacerbations, with viruses like rhinovirus, respiratory syncytial virus, and influenza causing inflammation of the airways, increased mucus production, and bronchial hyperresponsiveness, all of which can precipitate asthma symptoms in susceptible individuals 1. While exercise and cold air exposure can also trigger asthma symptoms, the temporal relationship between the development of upper respiratory symptoms and the subsequent asthma exacerbation strongly suggests that the viral infection is the primary trigger in this case.

Key Points to Consider

• The patient's recent symptoms of sore throat and rhinorrhea are consistent with an upper respiratory viral infection, which is a common trigger for asthma exacerbations 1.
• The management of the patient's asthma exacerbation should include treating the acute symptoms with bronchodilators and possibly corticosteroids, as well as addressing the underlying viral infection with supportive care 1.
• It is essential to monitor the patient's lung function and adjust treatment accordingly, with the goal of achieving an FEV1 or PEF of 70% or more of predicted value or personal best before discharge 1.
• The patient should be prescribed a course of corticosteroid therapy to reduce the risk of recurrence, typically 3 to 10 days 1.

Treatment Approach

• Administer oxygen and inhaled b2-agonists as needed to manage acute symptoms.
• Consider systemic corticosteroids to reduce inflammation and prevent recurrence.
• Provide supportive care for the underlying viral infection, such as rest, hydration, and symptom management.
• Monitor the patient's lung function and adjust treatment as needed to achieve optimal outcomes.

From the Research

Asthma Exacerbation Causes

The likely cause of asthma exacerbation in a marathon trainee who has been training for 2 months, recently trained in temperatures less than 10 degrees, and had a sore throat and rhinorrhea 3 days prior can be attributed to several factors.

• Respiratory viral infections are well recognized as major triggers of acute exacerbations of asthma in children and adults 2, 3, 4, 5, 6.
• The symptoms of sore throat and rhinorrhea 3 days prior to the exacerbation are indicative of a viral upper respiratory tract infection, which is a common trigger for asthma exacerbations 2, 5, 6.
• Rhinovirus is the most common virus associated with asthma exacerbations, and patients with asthma are not more susceptible to upper respiratory tract rhinovirus infections than healthy people but suffer from more severe consequences of the lower respiratory tract infection 2, 3, 4.
• The recent training in cold temperatures may have also contributed to the exacerbation, as cold air can trigger bronchospasm and increase the risk of asthma exacerbation.
• The fact that the trainee has been training for 2 months and recently experienced a sore throat and rhinorrhea suggests that the combination of physical stress and viral infection may have triggered the asthma exacerbation.

Viral Infections and Asthma

• Viral infections, particularly rhinovirus, are a major cause of morbidity and mortality in asthma, and impaired antiviral immunity to rhinovirus may lead to impaired viral clearance and hence prolonged symptoms 2, 3, 4.
• Respiratory viral infections cause asthmatic exacerbations by triggering recruitment of Th2-type cells into the lungs, and the host response to viral infection is likely to influence susceptibility to asthma exacerbation 2, 5.
• The development of a wider spectrum of vaccines to prevent viral infections is a potential strategy for reducing the rate of asthma exacerbation and improving the quality of life for patients with asthma 4.