3. Asthma Presentation

Clinical signs and symptoms of asthma can vary between patients and even within the same patient. When well, there may be no signs or symptoms. During an asthma exacerbation, hyperinflation of chest wall, cough, expiratory polyphonic wheezing, prolonged expiratory phase. In severe exacerbation, there may only be inspiratory phase heard and no expiratory wheezing. Chest x-rays may be clear or show hyper-expansion.

Asthma mortality is varied amongst countries and within the United States, deaths related to asthma are 10.6 deaths per million. Asthma is defined by airway inflammation and reversible bronchoconstriction. In some individuals, airway remodeling can occur over time and contribute to heterogenous airway narrowing. Death due to status asthmaticus is ultimately due to severe airway obstruction. Data shows that there are different subtypes of acute asthma exacerbation: Slow onset fatal asthma & Rapid onset fatal asthma. Slow onset fatal asthma is the predominant type (estimated 80-85%) of asthma related death.

In these individuals, there are progressive symptoms for weeks. These individuals typically have eosinophilic inflammation and worsening obstruction of airway lumen with mucus plugging that occur over days to weeks. Rapid onset fatal asthma occurs less often and death occurs typically under 6 hours of symptom onset. In these individuals, death is due to severe smooth muscle bronchospasm and the predominant inflammatory cell is neutrophils.  There are no specific characteristics to identify this subtype of patients. Overall major risk factors for individuals more likely to have die of status asthmaticus include recently poorly controlled asthma or history of a near death event. Minor risk factors have been described of varying importance and include sensitivity to aeroallergens, food allergy, aspirin exacerbated respiratory disease, exercise, illicit drug use, menstruation, respiratory viral infection, smoking, vaping, air pollution, poor adherence to medications and psychosocial factors. Other factors such as poor perception of dyspnea has also been thought to contribute to delays in seeking care in fatal exacerbations. 

Increased probability that symptoms are due to asthma if:
 

• More than one type of symptom (wheeze, shortness of breath, cough, chest tightness) 
  
  
• Symptoms often worse at night or in the early morning
  
  
• Symptoms vary over time and in intensity 
  
  
• Symptoms are triggered by viral infections, exercise, allergen exposure, changes in weather, laughter, irritants such as car exhaust fumes, smoke, or strong smells 

Decreased probability that symptoms are due to asthma if:
 

• Isolated cough with no other respiratory symptoms 
  
  
• Chronic production of sputum 
  
  
• Shortness of breath associated with dizziness, light-headedness or peripheral tingling 
  
  
• Chest pain 
  
  
• Exercise-induced dyspnea with noisy inspiration (stridor) 

Other aspects of history and physical may provide additional information to classify asthma phenotypes and endotypes:

• Pattern: seasonality, continuous vs. episodic, character (onset, duration, frequency), triggers
  
  
• Development: age at onset, airway injury, progression, current management 
  
  
• Family history: atopy, asthma, other 
  
  
• Social: environment, siblings, daycare 
  
  
• Impact on family: emergency visits, lost work or school, activity limitations, economic, patient and family perception
  
  
• Cellular patterns: eosinophilic, neutrophilic, mixed cellular inflammation, pauci-immune 
  
  
• Response to previous therapies