Asthma guidelines and treatment

What is asthma? A chronic lung disease that inflames and narrows the airways. Asthma affects people of all ages, but it most often starts during childhood. In the United States, more than 25 million people are known to have asthma. About 7 million of these people are children. Up to 4000 deaths/year attributable to asthma, many of which are preventable.

Controversy There is a disparity in asthma prevalence between developed and underdeveloped countries. Decreased prevalence in underdeveloped countries has been ascribed to early childhood infections that alter the immune response of the TH1 response and away from the TH2 response (triggers allergic inflammation). Between 70-90% of patients with asthma have allergies.

Pathogenesis of asthma Airway inflammation is marked by infiltration with eosinophils, mast cells, lymphocytes, and neutrophils; subepithelial fibrosis; mucous gland hyperplasia; & increased smooth muscle mass. Histamine, leukotrienes, tryptase play a role in early phase response. Cytokines play a role in late phase response leading to airway remodeling.

Your clinic Cough (dry or productive), dyspnea, wheezing, chest tightness. Triggers: URI, cold air, exercise, allergies. Worse at night or early am.

Differential COPD (less reversible, older) Vocal cord dysfunction (flow vol loop, abrupt) Heart failure (crackles, edema) Bronchiectasis (rhonchi, crackles, clubbing) ABPA (infiltrates, IgE) CF (large amt purulent sputum, rhonchi, crackles) Mechanical obs (flow vol loop, central wheeze)

Samter’s Triad 1. Asthma 2. Nasal polyps 3. Allergy to ASA/NSAIDS 3-5% of adults with asthma

Clinic First history/physical Spirometry

Normal spirometry  bronchial challenge test

Goals 1. Maintain normal function status 2. Preserve normal lung function 3. Reduce the need for rescue albuterol<2X/wk 4. Reduce symptom flares that require intense therapy 5. Decrease side effects of treatment

Medications SABA – albuterol (Proair, Ventolin) – FOR ALL ICS – fluticasone (Flovent), budesonide (Pulmicort), mometasone (Asmanex) LABA – salmeterol (Serevent), formoterol (Foradil) Immunomodulator – omalizumab (Xolair) 2nd line options: LTRA – montelukast (Singulair) Theophylline Cromolyn (Intal)

Side effects SABA – Tachycardia ICS – PNA, thrush, osteoporosis Immunomodulator – Lymphoma

When to refer Both pulmonologists and allergists/immunologists have specialty training in asthma care. experienced a life-threatening asthma exacerbation required hospitalization or >2 bursts of oral cst in 1 yr >5 years old requiring step 4 or > Not controlled after 3-6 mo of active therapy & appropriate monitoring The patient appears unresponsive to therapy The diagnosis of asthma is uncertain Other conditions present which complicate management (nasal polyposis, chronic sinusitis, severe rhinitis, allergic bronchopulmonary aspergillosis, COPD, vocal cord dysfunction) Additional diagnostic tests are needed (skin testing for allergies, bronchoscopy, complete pulmonary function tests

References www.uptodate.com www.medscape.com MKSAP