Inflammatory disorder with airway hyperresponsiveness + variable airflow obstruction.o

Affects ~5% population; ~85% of cases by age 40; linked to ADAM-33 ? o

Classic triad: wheezing, cough, and dyspnea; others include chest tightness and sputum.o

Symptoms are typically chronic with episodic exacerbation.o

Respiratory irritants (perfumes, smoke, detergents, strong odors)o
Allergens (pets, carpets, dust mites, pollen)o
Infections (URI, bronchitis, sinusitis)o
Drugs (e.g. ASA [leukotrienes], βB [bronchospasm], morphine [histamine release] )o
Stress
Cold air

Exacerbations: important to note frequency, severity, duration, and required treatment including need for steroids, ED visits, hospitalizations, and intubations.o

Wheezing and prolonged expiratory phase.o
Presence of nasal polyps, rhinitis, rash → allergic component
Exacerbation → pulsus paradoxus, use of accessory muscles of respiration.o

↓ peak expiratory flow rate (PEFR)o
Spirometry: ↓FEV1, ↓FEV1/FVC ratio, coved flow-volume loop
Lung volumes: ± ↑RV and ↑TLC
Pos. bronchodilator response (↑FEV1 ≥ 12% ) strongly suggestive of asthma
Methacoline challenge (↓FEV1 ≥ 20% ) useful if asthma suspected but PFTs normal, Sens. > 90%, NPV 95%o
Allergy suspected → consider: serum IgE, eosinophils, skin testing/RAST
Sputum: Curschmann's spirals (mucus casts of distal airways), Charcot-Leyden crystals

Mechanical airway obstruction or structural airway abnormalities (e.g. tumor)o
Laryngeal or vocal cord dysfunction (e.g. due to GERD or postnasal drip)o
COPD, CHF, vasculitis: consider in older Patients with new diagnosis of "asthma"o
Other pulmonary causes: bronchiectasis, PE, aspiration, sarcoidosis, ILD

Asthma + syndromes
Atopy = asthma + allergic rhinitis + atopic dermatitis
ASA-sensitive asthma (Samter's syndrome) = asthma + ASA sensitivity + nasal polyps
ABPA = asthma + pulmonary infiltrates + allergic response to Aspergillus
ABPA: allergic bronchopulmonary aspergillosis
Churg-strauss = asthma + eosinophilia + granulomatous vasculitis

"Quick-relief" medications
Treatment of choice: short-acting inhaled β2-agonists (albuterol, pirbuterol, terbutaline)o
Inhaled anticholinergics (ipratropium) improve β2-agonist delivery
Systemic corticosteroids

"Long-term-control" medications
Treatment of choice: inhaled or systemic corticosteroids
Long-acting inhaled β2-agonists (salmeterol)o
Nedocromil/cromolyn: useful in young patients, exercise-induced bronchospasm
Theophylline: useful in hard-to-control patients, PO convenience, but high side effects profile
Leukotriene modifiers: some patients very responsive, especially aspirin-sensitive asthma

Other
Behavioral modification: identify and avoid triggers
Immunotherapy (e.g. desensitization): may be useful if significant allergic component
Omalizumab (SC anti-IgE) may be useful in severe allergic asthma

Principles of management
Use quick-relief medications for all patients
Persistent asthma requires Long-term-control medications; anti-inflammatory meds preferred
Step up treatment if control not maintained; step down if in control

Mild Intermittent: use only prn albuterol; if related to exercise, use albuterol one-half hour prior to exercise; also used: cromolyn one half-hour prior to exercise. o

Mild Persistent: daily: low dose inhaled steroids; and use albuterol intermittently as needed. Also may use po singulair or inhaled cromolyn. o

Moderate Persistent: use peak flow meter daily; use med dose inhaled steroid or low dose steroids plus serevent or singulair. Others switch to Advair. PO steroids prn. o

Severe Persistent: use peak flow meter daily; po steroids as needed. Daily meds to include high dose inhaled steroids, singulair, serevent or possibly Advair.o