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KembaraXtra-Medicine – Asthma
Asthma is a chronic inflammatory disease of the airways involving multiple cells, including mast cells, eosinophils, neutrophils, T lymphocytes, macrophages, and epithelial cells. This inflammation leads to recurrent episodes of cough (often at night or early morning), wheezing, shortness of breath, and chest tightness. These episodes are associated with variable and usually reversible airflow obstruction, either spontaneously or with treatment. Status asthmaticus refers to acute severe asthma that does not respond to standard therapies such as inhaled beta-agonists or subcutaneous epinephrine and may persist for hours, representing a life-threatening emergency.
Asthma is also referred to as bronchospasm, reactive airway disease, or asthmatic bronchitis. In the United States, approximately 7.7% of the population has asthma, with rising prevalence among adults, older individuals, women, African Americans, and people living below the poverty level. Globally, about 300 million people are affected, with projections reaching 400 million. Asthma accounts for significant healthcare use, including hundreds of thousands of hospitalizations and millions of emergency visits annually. Although mortality has declined overall, it remains unchanged in children aged 1–14 years. Many patients develop symptoms early in life, with 50–80% of children becoming symptomatic before age five.
Clinical presentation varies depending on severity and disease stage. Physical examination may be normal between attacks, but persistent or acute asthma often shows wheezing and prolonged expiration. Severe asthma and status asthmaticus may present with tachypnea, tachycardia, use of accessory muscles, pulsus paradoxus, altered mental status, paradoxical abdominal movement, or even a “silent chest,” which signals critical airflow obstruction. Risk factors for severe or fatal asthma include prior intubation, poor disease control, steroid dependence, smoking, obesity, psychiatric illness, advanced age, and limited access to medical care.
Asthma pathophysiology reflects a complex interaction between genetic susceptibility and environmental triggers. Allergic (atopic) asthma is driven by IgE-mediated responses to allergens, while nonallergic asthma often presents in adulthood following respiratory infections or stress. Occupational exposures, air pollutants, mold, exercise, medications such as NSAIDs or beta-blockers, and tobacco smoke can precipitate symptoms. Type-2 inflammatory pathways play a central role, involving cytokines such as IL-4, IL-5, and IL-13, leading to eosinophilia, IgE production, airway hyperresponsiveness, and remodeling. Genetic associations, including ADAM33 and other immune-related loci, further influence disease expression.
Diagnosis requires demonstration of airflow obstruction with reversibility. Spirometry before and after bronchodilator use is the preferred diagnostic test in patients older than five years, with reversibility defined as an increase in FEV₁ of at least 12% and 200 mL. Normal spirometry does not exclude asthma; bronchial challenge testing may be used when suspicion remains high. In young children, diagnosis is often clinical after exclusion of alternatives. Differential diagnoses include COPD, GERD, postnasal drip, vocal cord dysfunction, heart failure, pulmonary embolism, anxiety disorders, and interstitial lung disease.
Laboratory and ancillary testing help assess severity and guide management. Blood eosinophilia and elevated IgE support an allergic phenotype. Arterial blood gases are useful in acute severe attacks to assess hypoxia and hypercapnia. Imaging is usually normal but may show hyperinflation during exacerbations. Fractional exhaled nitric oxide and allergy testing can help phenotype asthma and predict response to therapy. Regular spirometry and peak flow monitoring are important for long-term assessment and self-management.
Management focuses on achieving and maintaining asthma control. Nonpharmacologic measures include trigger avoidance, smoking cessation, patient education, proper inhaler technique, and regular follow-up. Pharmacologic treatment follows a stepwise approach based on symptom frequency and severity. Short-acting beta-agonists are used for quick relief, while inhaled corticosteroids are the cornerstone of maintenance therapy. Additional controllers include long-acting beta-agonists (only in combination with inhaled corticosteroids), leukotriene receptor antagonists, long-acting muscarinic antagonists, and theophylline in selected cases. Therapy is stepped up when control is poor and stepped down when stable.
Patients with severe or refractory asthma may benefit from advanced therapies. Biologic agents targeting IgE, IL-5, IL-5 receptors, IL-4/IL-13 pathways, or thymic stromal lymphopoietin are used in carefully selected patients based on phenotype and biomarkers. Bronchial thermoplasty is an option for some adults with severe persistent asthma unresponsive to maximal medical therapy. Status asthmaticus requires aggressive management with oxygen, frequent bronchodilators, systemic corticosteroids, adjunctive agents such as magnesium sulfate, and ventilatory support when necessary.
Overall, asthma outcomes depend on individualized care, control of comorbid conditions, adherence to therapy, and early recognition of worsening symptoms. With appropriate management, most patients can achieve good symptom control, reduce exacerbations, and maintain normal activity levels.
Asthma is a chronic inflammatory disease of the airways involving multiple cells, including mast cells, eosinophils, neutrophils, T lymphocytes, macrophages, and epithelial cells. This inflammation leads to recurrent episodes of cough (often at night or early morning), wheezing, shortness of breath, and chest tightness. These episodes are associated with variable and usually reversible airflow obstruction, either spontaneously or with treatment. Status asthmaticus refers to acute severe asthma that does not respond to standard therapies such as inhaled beta-agonists or subcutaneous epinephrine and may persist for hours, representing a life-threatening emergency.
Asthma is also referred to as bronchospasm, reactive airway disease, or asthmatic bronchitis. In the United States, approximately 7.7% of the population has asthma, with rising prevalence among adults, older individuals, women, African Americans, and people living below the poverty level. Globally, about 300 million people are affected, with projections reaching 400 million. Asthma accounts for significant healthcare use, including hundreds of thousands of hospitalizations and millions of emergency visits annually. Although mortality has declined overall, it remains unchanged in children aged 1–14 years. Many patients develop symptoms early in life, with 50–80% of children becoming symptomatic before age five.
Clinical presentation varies depending on severity and disease stage. Physical examination may be normal between attacks, but persistent or acute asthma often shows wheezing and prolonged expiration. Severe asthma and status asthmaticus may present with tachypnea, tachycardia, use of accessory muscles, pulsus paradoxus, altered mental status, paradoxical abdominal movement, or even a “silent chest,” which signals critical airflow obstruction. Risk factors for severe or fatal asthma include prior intubation, poor disease control, steroid dependence, smoking, obesity, psychiatric illness, advanced age, and limited access to medical care.
Asthma pathophysiology reflects a complex interaction between genetic susceptibility and environmental triggers. Allergic (atopic) asthma is driven by IgE-mediated responses to allergens, while nonallergic asthma often presents in adulthood following respiratory infections or stress. Occupational exposures, air pollutants, mold, exercise, medications such as NSAIDs or beta-blockers, and tobacco smoke can precipitate symptoms. Type-2 inflammatory pathways play a central role, involving cytokines such as IL-4, IL-5, and IL-13, leading to eosinophilia, IgE production, airway hyperresponsiveness, and remodeling. Genetic associations, including ADAM33 and other immune-related loci, further influence disease expression.
Diagnosis requires demonstration of airflow obstruction with reversibility. Spirometry before and after bronchodilator use is the preferred diagnostic test in patients older than five years, with reversibility defined as an increase in FEV₁ of at least 12% and 200 mL. Normal spirometry does not exclude asthma; bronchial challenge testing may be used when suspicion remains high. In young children, diagnosis is often clinical after exclusion of alternatives. Differential diagnoses include COPD, GERD, postnasal drip, vocal cord dysfunction, heart failure, pulmonary embolism, anxiety disorders, and interstitial lung disease.
Laboratory and ancillary testing help assess severity and guide management. Blood eosinophilia and elevated IgE support an allergic phenotype. Arterial blood gases are useful in acute severe attacks to assess hypoxia and hypercapnia. Imaging is usually normal but may show hyperinflation during exacerbations. Fractional exhaled nitric oxide and allergy testing can help phenotype asthma and predict response to therapy. Regular spirometry and peak flow monitoring are important for long-term assessment and self-management.
Management focuses on achieving and maintaining asthma control. Nonpharmacologic measures include trigger avoidance, smoking cessation, patient education, proper inhaler technique, and regular follow-up. Pharmacologic treatment follows a stepwise approach based on symptom frequency and severity. Short-acting beta-agonists are used for quick relief, while inhaled corticosteroids are the cornerstone of maintenance therapy. Additional controllers include long-acting beta-agonists (only in combination with inhaled corticosteroids), leukotriene receptor antagonists, long-acting muscarinic antagonists, and theophylline in selected cases. Therapy is stepped up when control is poor and stepped down when stable.
Patients with severe or refractory asthma may benefit from advanced therapies. Biologic agents targeting IgE, IL-5, IL-5 receptors, IL-4/IL-13 pathways, or thymic stromal lymphopoietin are used in carefully selected patients based on phenotype and biomarkers. Bronchial thermoplasty is an option for some adults with severe persistent asthma unresponsive to maximal medical therapy. Status asthmaticus requires aggressive management with oxygen, frequent bronchodilators, systemic corticosteroids, adjunctive agents such as magnesium sulfate, and ventilatory support when necessary.
Overall, asthma outcomes depend on individualized care, control of comorbid conditions, adherence to therapy, and early recognition of worsening symptoms. With appropriate management, most patients can achieve good symptom control, reduce exacerbations, and maintain normal activity levels.
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