- Asthma
- Reversible airway obstruction
- Airway inflammation (Cytokine and IgE mediated)
- Increased Bronchial hyperresponsiveness (bronchospasm)
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Status Asthmaticus
- Severe airway obstruction developing over days-weeks
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Prevalence: 300 Million people
- Variable from country to country (may affect as many as 18% of population in some countries)
- Mortality: 250,000 deaths/year worldwide
- Epidemiology
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United States
- Adults and Children
- Prevalence: 25.7 million people in United States diagnosed with Asthma (2011)
- Asthma-related deaths per year: 3345 (in 2011)
- At least 4.1 million Asthma Exacerbations in children in 2011
- http://www.cdc.gov/nchs/data/series/sr_03/sr03_035.pdf
- Emergency department Asthma visits: 1.8 Million/year (2004-2005)
- Children: 168 per 10,000
- Adults: 50 per 10,000
- Hospitalization rate: 10-25% (resulted in 497,000 Asthma hospitalizations)
- From National Health Interview Survey
- http://www.cdc.gov/nchs/data/series/sr_10/sr10_228.pdf
- Children: Annual statistics for children under age 15 years in U.S.
- Asthma Prevalence: 5% or 5 million children
- Asthma clinic visits: 3 million per year
- Asthma emergency department visits: 570,000
- Asthma hospitalizations: 164,000 per year
- Asthma Missed school days: 10 million per year
- Asthma Prescriptions: 8.7 million
- Ethnicity: Outcomes much worse in black children
- Prevalence 26% higher in black children
- More severe Disability
- More frequent hospitalizations
- Black children 4-6 times more likely to die of Asthma
- Hallmark of Asthma: Bronchial wall Hyperresponsiveness
- Develops as a final step in "allergic march"
- Base: Allergic predisposition by Family History
- Step 1: Onset of allergic disease in infants
- Food Allergy GI disorders (serum IgE increased)
- Atopic Dermatitis
- Step 2: Progression of allergy in young children
- Allergic Rhinitis and Allergic Conjunctivitis
- Consider early Antihistamines and Immunotherapy
- May prevent progression to Asthma
- Warner (2001) J Allergy Clin Immunol 108:929-37 [PubMed]
- Step 3: Asthma develops
- Early Phase Asthma Reaction: Bronchoconstriction
- Antigenic Stimulation of Bronchial wall
- Extrinsic Asthma (allergic triggers)
- See Intrinsic Asthma for non-allergic triggers
- Associated with irritants as seen in adults
- Mast Cell Degranulation releases
- Histamine
- Chemotactics
- Proteolytics
- Heparin
- Findings
- Smooth Muscle Bronchoconstriction
- Late Phase Asthma Reaction: Bronchial Inflammation
- Cytokine and IgE mediated airway inflammation
- Inflammatory Cells Recruited
- Neutrophils
- Monocytes
- Eosinophils
- Release Cytokines, Vasoactives, Arachidonic Acid
- Epithelial and Endothelial Cell inflammation
- Release of Interleukin 3-6, TNF, Interferon-gamma
- Findings
- Bronchial edema and mucous plugging
- Ultimately may progress to airway remodelling
- Inspissated thick mucous may completely obstruct the airway resulting in death
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Family History
- One parent with Asthma: up to 25% risk for child
- Two parents with Asthma: up to 50% risk for child
- Parental Tobacco Abuse
- Associated Aspirin or NSAID allergy
- Classic Triad: Asthma, Nasal Polyps, Aspirin Allergy
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RSV Bronchiolitis history
- Strongly associated with later development of Asthma
- Strenuous Exercise in areas of high ozone (pollution)
- McConnell (2002) Lancet 359:386-91 [PubMed]
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Extrinsic Asthma (Allergic triggers)
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Intrinsic Asthma (Irritant triggers)
- Mixed Asthma (Extrinsic and Intrinsic Asthma)
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Occupational Asthma
- Toluene diisocyanate
- Polyvinyl chloride
- Phthalic anhydride
- Trimellitic anhydride
- Plicatic acid (Western Red Cedar trees)
- Metal salts
- Platinum
- Nickel
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Aspirin or NSAID induced Asthma
- Jenkins (2004) BMJ 328:434-40 [PubMed]
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Exercise Induced Asthma
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Cough Variant Asthma
- Very common! (Especially in children)
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