Table of Contents
Asthma
Types
Immunology
Diagnosis
Treatment
Caution
Asthma
Chronic inflammatory disease of respiratory tree to various sensitizing stimuli resulting in reversible airway obstruction
Characterized by
Bronchial hyperresponsiveness
?
Types
Allergic
Atopic
Extrinisic
Most common form
Triggered by inhaled antigens (dust mites, pollen, pet dander, mold)
Biologics
Immunologic based
Non-allergic (intrinisic)
non-atopic
intrinisic* 10% of asthmatics
triggered by factors not related to allergies
exercise
cold/dry allergic
smoke
viruses
stress/anxiety
Immunology
Main immunologic cells
Macrophages
Dendritic cells
Eosinophil
Immunity
Innate
Adaptive
Humoral (B cells)
Memory
Effector (plasma)
Antigen presenting cell
Cell-mediated (T cells)
T helper cells (CD4): mainly TH2
IL-4 and IL-13 (dupilumab)
indications
adults
moderate-to-severe atopic dermatitis (eczema)
IL-5 (mepolizumab, benralizumab, reslizumab)
indications
age 18 and above
severe persistent asthma, refractory to other treatment
eosinophilia, but not elevated IgE
side effects (OI: herpes zoster with mepolizumab)
IgE (omalizumab)
indications
age 12 and above
moderate to severe persistent asthma, refractory to other treatment
serum IgE elevated (dose by IgE and weight)
only administered in health care setting
possible anaphylaxis
Cytotic T-cells (CD8)
Diagnosis
Pattern of symptoms and response to therapy
Spirometry and/or PFTs + BD response (≥12%)
FEV1/FVC, FEV1, FVC
TLC, DLCO
Challenge testing
Exercised induced bronchoconstriction & chronic cough
Exercised
Cold air
Methacholine
Fraction of exhaled NO
High values of FENO in asthma that returns to normal after treatment with glucocorticoids
Eosinophilic inflammation in airways stimulates airway epithelial cells to produce NO
Sputum eosinophiles
Charcot leyden crystals
Curschmann's spirals
Treatment
Anti-inflammatory medications
Corticosteroids: PO, inhaled, IV, IM
Direct bronchodilators (short and long acting)
b2-agonists (increases cAMP): salbutamol, albuterol, levalbuterol
anti-cholinergics (M3 receptor in airway smooth muscle)
helpful/recommended in acute setting
ipratropium bromide
methylxanthines
theophylline
aminophylline (short acting)
?
Mast-cell stabilizers
Leukotriene inhibitors
Zileuton (Zylfo): leukotriene synthesis inhibitor
Monteleukast (Singulair): leukotriene receptor antagonist
Combination medications
Dulera: mometasone furoate and formoterol fumarate
Symbicort: budesonide and formoterol fumarate
Advair: fluticasone and salmeterol
Bronchial thermoplasty: approved for severe persistent refractory asthma, intrinisic and extrinisic (but other options better for extrinsic)
Caution
aspirin
ACE inhibitor
permissive hypercapnia