Can a person develop exercise-induced asthma at an older age?

Exercise-Induced Asthma Can Develop at Any Age

Yes, a person can develop exercise-induced asthma (EIA) or exercise-induced bronchoconstriction (EIB) at an older age, even if they have never experienced it before. This condition is not limited to childhood onset and can manifest for the first time in adulthood 1.

Understanding Exercise-Induced Bronchoconstriction (EIB)

EIB is characterized by temporary narrowing of the airways during or after physical activity, resulting in symptoms such as:

• Wheezing
• Shortness of breath
• Chest tightness
• Coughing
• Decreased exercise performance

EIB can occur in two distinct populations:

1. Individuals with underlying chronic asthma (where exercise is a trigger)
2. People without chronic asthma who only experience symptoms with exercise

Pathophysiology of Late-Onset EIB

The development of EIB at an older age is related to several mechanisms:

1. Osmotic Changes: During exercise, increased ventilation leads to water loss from the airways, creating a hyperosmolar environment that triggers mast cell activation and inflammatory mediator release 1.

2. Thermal Effects: Although less significant than osmotic changes, cooling and rewarming of airways during exercise may contribute to bronchoconstriction 1.

3. Inflammatory Response: Exercise triggers the release of mediators including leukotrienes, prostaglandins, histamine, and tryptase from mast cells and eosinophils, leading to smooth muscle contraction 1.

4. Environmental Factors: Prolonged exposure to specific environments can increase risk:

   • Cold, dry air exposure
   • Chlorinated swimming pools
   • Air pollutants
   • Ice rink emissions 1

Diagnosis of Late-Onset EIB

Symptoms alone are insufficient for diagnosis, as they are neither sensitive nor specific for EIB 1. Objective testing is essential:

1. Exercise Challenge Testing: The gold standard involves:

   • Running on a treadmill for 6-8 minutes at 80-90% of maximum heart rate
   • Breathing dry air through a nose clip
   • Measuring FEV1 before and after exercise
   • A decline in FEV1 ≥15% indicates EIB 1

2. Surrogate Tests:

   • Eucapnic voluntary hyperpnea (EVH)
   • Mannitol inhalation challenge
   • Hyperosmolar saline challenge 1

Management of EIB

Treatment should be comprehensive and includes:

Pharmacologic Approaches:

1. First-Line Prevention:

   • Short-acting β2-agonists (SABAs) 5-20 minutes before exercise 1
   • Most effective for short-term protection and accelerating recovery

2. For Persistent Symptoms:

   • Inhaled corticosteroids (ICS) as primary controller therapy 1
   • Leukotriene receptor antagonists (can be used intermittently or as maintenance) 1
   • Mast cell stabilizers (where available) 1

3. Important Caution:

   • Daily use of β2-agonists (both short and long-acting) can lead to tolerance with reduced protection duration 1, 2

Non-Pharmacologic Strategies:

1. Warm-up Exercise: Performing warm-up exercises 30-60 minutes before main exercise can induce a refractory period 1

2. Environmental Modifications:

   • Face masks or scarves to warm and humidify inspired air 1
   • Avoiding exercise in cold, dry environments when possible
   • Reducing exposure to chlorinated pools or ice rinks if these trigger symptoms

3. Physical Conditioning: Improving overall fitness may reduce EIB severity 3

Special Considerations for Late-Onset EIB

When EIB develops for the first time in adulthood, consider:

1. Differential Diagnosis:

   • Exercise-induced laryngeal dysfunction (EILD)
   • Vocal cord dysfunction
   • Cardiac causes of dyspnea
   • Deconditioning 1

2. Environmental/Occupational Exposures:

   • New workplace exposures
   • Changes in exercise environment
   • Swimming pool workers and elite swimmers have increased risk due to chloramine exposure 1

Monitoring and Follow-up

Regular assessment of asthma control is essential using validated tools like the Asthma Control Test (ACT) 1. For those who develop EIB later in life, monitoring should include:

• Periodic reassessment of lung function
• Evaluation of response to preventive medications
• Adjustment of treatment based on symptom control and activity levels

Remember that late-onset EIB may represent the first manifestation of underlying asthma, so comprehensive evaluation for other asthma symptoms is warranted.