What is the management plan for reactive airway disease?

Reactive Airway Disease: Diagnosis and Management

Reactive airway disease (RAD) is a general term for respiratory illnesses characterized by wheezing, bronchospasm, and airway hyperresponsiveness that requires a comprehensive management approach focused on controlling symptoms, reducing inflammation, and preventing exacerbations to improve morbidity, mortality, and quality of life.

Definition and Pathophysiology

• RAD is characterized by variable and recurring symptoms, airflow obstruction, bronchial hyperresponsiveness, and underlying inflammation 1
• The condition involves multiple cell types including mast cells, eosinophils, neutrophils, T lymphocytes, macrophages, and epithelial cells that contribute to chronic airway inflammation 1
• In susceptible individuals, this inflammation causes recurrent episodes of wheezing, breathlessness, chest tightness, and coughing, particularly at night or early morning 1
• These episodes are usually associated with widespread but variable airflow obstruction that is often reversible either spontaneously or with treatment 1

Types of Reactive Airway Disease

• Occupational asthma: Develops due to workplace exposures and includes:

  • IgE-mediated asthma after a latency period 1
  • Irritant asthma with or without latency period, including Reactive Airways Dysfunction Syndrome (RADS) 1
  • Asthma due to specific occupational agents with unknown pathomechanisms 1

• Reactive Airways Dysfunction Syndrome (RADS): An asthma-like condition that develops after a single high-level exposure to irritating volatile substances 2, 3

  • Symptoms develop within hours or minutes after exposure 3
  • Differs from typical asthma in that it doesn't involve allergic mechanisms 2
  • Can lead to long-term respiratory sequelae and chronic airways disease 3

• Work-aggravated asthma: Pre-existing asthma worsened by workplace exposures, typically due to occupational irritants 1

Diagnosis

• Diagnosis is based on clinical presentation, medical history, physical examination, and objective measurements of lung function 1

• Key diagnostic elements include:

  • History of variable respiratory symptoms (wheezing, shortness of breath, chest tightness, cough) 1
  • Confirmation of variable airflow limitation through spirometry 1
  • Documentation of airway hyperresponsiveness through bronchoprovocation testing when spirometry is normal 1
  • Exclusion of alternative diagnoses 1

• Special diagnostic challenges:

  • Cough variant asthma: Cough may be the principal or only manifestation, especially in children 1
  • Vocal cord dysfunction: May mimic or coexist with asthma but typically doesn't respond to asthma medications 1
  • Comorbid conditions like GERD, sleep apnea, or allergic bronchopulmonary aspergillosis may complicate diagnosis 1

Management Approach

Assessment of Control

• Determine if asthma is well-controlled or not well-controlled based on:
  • Impairment: frequency and intensity of symptoms and functional limitations 1
  • Risk: likelihood of exacerbations, progressive lung function decline, or medication adverse effects 1
• This determination drives clinical decisions to maintain, step up, or step down treatment 1

Stepwise Treatment Approach

Step 1: Mild Intermittent Disease

• Short-acting beta-agonists (SABA) as needed 1
• No controller medication needed 1

Step 2: Mild Persistent Disease

• Low-dose inhaled corticosteroids (ICS) as preferred controller 1
• Alternatives: leukotriene modifiers, theophylline, cromolyn, or nedocromil 1

Step 3: Moderate Persistent Disease

• Low-to-medium dose ICS plus long-acting beta-agonist (LABA) 1
• Alternative: Medium-dose ICS alone or low-to-medium dose ICS plus either leukotriene modifier or theophylline 1

Step 4: Severe Persistent Disease

• High-dose ICS plus LABA 1
• Add systemic corticosteroids if needed 1
• Consider monoclonal anti-IgE therapy 1

Management of Exacerbations

• Home management:

  • Develop written asthma action plan 1
  • Teach recognition of early warning signs 1
  • Adjust medications (increase SABA, potentially add oral corticosteroids) 1
  • Monitor response and seek medical care if deterioration occurs 1

• Urgent/Emergency care:

  • Assess severity through lung function measures and symptom assessment 1
  • Provide supplemental oxygen 1
  • Administer repetitive or continuous SABA 1
  • Give oral systemic corticosteroids 1
  • Consider adjunctive treatments like magnesium sulfate in severe cases 1

Special Situations

• Exercise-Induced Bronchoconstriction (EIB):

  • Pretreat with SABA, leukotriene receptor antagonists, cromolyn or nedocromil 1
  • Avoid frequent use of LABA for pretreatment 1
  • Consider warm-up period or mask/scarf over mouth for cold-induced EIB 1

• Pregnancy:

  • Monitor asthma control during all prenatal visits 1
  • Maintain treatment as it's safer than having poorly controlled asthma 1
  • Albuterol is the preferred SABA; budesonide is the preferred ICS during pregnancy 1

• Surgery:

  • Assess asthma control before surgery 1
  • Consider short course of oral corticosteroids if lung function is not well controlled 1
  • For patients on oral corticosteroids or high-dose ICS, give hydrocortisone during surgery 1

• Occupational Asthma:

  • Whenever possible, remove exposure to the causative agent for best health outcome 1
  • If removal is not possible, reduction is the second-best option 1
  • Respirators provide limited value in protection 1

Pitfalls and Caveats

• Avoid using labels like "wheezy bronchitis," "recurrent pneumonia," or "reactive airway disease" in young children without proper diagnosis, as this may delay appropriate asthma treatment 1

• Beta-blockers can aggravate bronchospastic symptoms in patients with asthma, but cardioselective beta-blockers may be tolerated in patients with mild to moderate reactive airway disease when clinically indicated 4

• Underuse of corticosteroids is a common factor in preventable asthma deaths 1

• Recognize that RADS may not respond to typical asthma treatments and can become chronic if symptoms persist for more than 6 months 5

• Consider high-dose vitamin D as a potential treatment for refractory RADS cases 5

• Early recognition and diagnosis is necessary for timely and appropriate preventative measures in occupational asthma 1

Follow-up and Monitoring

• Regular monitoring of symptoms and peak expiratory flow (PEF) 1
• Provide patients with a PEF meter and self-management plan 1
• Schedule follow-up within 24-48 hours after an acute exacerbation 1
• Modify treatment according to level of control 1
• Consider referral to an asthma specialist for atypical presentations, difficult differential diagnoses, or when additional testing is indicated 1