Preschool Wheezy Children

Gamal Rabie Agmy, MD, FCCP Professor of chest Diseases, Assiut university

Definition of Asthma

A chronic inflammatory disorder of the airways

Many cells and cellular elements play a role

Chronic inflammation is associated with airway hyperresponsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness, and coughing

Widespread, variable, and often reversible airflow limitation

Source: Peter J. Barnes, MD

Asthma Inflammation: Cells and Mediators

Source: Peter J. Barnes, MD

Mechanisms: Asthma Inflammation

Source: Peter J. Barnes, MD

Asthma Inflammation: Cells and Mediators

Smooth Muscle

Dysfunction

Airway

Inflammation

• Inflammatory Cell

Infiltration/Activation

• Mucosal Edema

• Cellular Proliferation

• Epithelial Damage

• Basement Membrane

Thickening

• Bronchoconstriction

• Bronchial Hyperreactivity

• Hypertrophy/Hyperplasia

• Inflammatory Mediator

Release

Symptoms/Exacerbations

Asthma Pathobiology

Pathology of Asthma

Factors that Exacerbate Asthma

Allergens

Respiratory infections

Exercise and hyperventilation

Weather changes

Sulfur dioxide

Food, additives, drugs

Factors that Influence Asthma

Development and Expression

Host Factors

Genetic

- Atopy

- Airway

hyperresponsiveness

Gender

Obesity

Environmental Factors

Indoor allergens

Outdoor allergens

Occupational sensitizers

Tobacco smoke

Air Pollution

Respiratory Infections

Diet

Is it Asthma?

Recurrent episodes of wheezing

Troublesome cough at night

Cough or wheeze after exercise

Cough, wheeze or chest tightness after exposure to airborne allergens or pollutants

Colds “go to the chest” or take more than 10 days to clear

90% of the asthma problem is not seen:

The inflammation!!!

Bronchospasm= 10%

When this disappears…

Have we eliminated this?

Symptoms

Underlying

disease

Pediatric Asthma Not all wheezing is asthma

Wheezing occurrences in children:

- single episode in 30% to 50% of children

before 5 yr of age

- 40% who wheeze before 3 yr of age continue

at 6 yr (“persistent wheezers”)

- 50% of infants who wheeze once will wheeze

again within several months

Wheezing in Children - Phenotypes

Childhood asthma phenotypes

Childhood asthma phenotypes

*A 2012 study described 2 "new" phenotypes for

young children with wheezing: "boys atopic

multiple-trigger" and "girls nonatopic uncontrolled

wheeze". JACI, 2012.

*Toward a definition of asthma phenotypes in

childhood: early viral wheezers, multitrigger

wheezers (MTWs), and nonatopic uncontrolled

wheezers (NAUWs). Some children have “allergic

bronchitis” rather than “asthma”. JACI, 2012.

Diagnosing Asthma in Young

Children – Asthma Predictive

Index

• > 4 episodes/yr of wheezing lasting more than 1 day affecting sleep in a child with one MAJOR or two MINOR criteria

• Major criteria – Parent with asthma

– Physician diagnosed

atopic dermatitis

• Minor criteria

– Physician diagnosed

allergic rhinitis

– Eosinophilia (>4%)

– Wheezing apart from

colds

1Adapted from Castro-Rodriquez JA, et al. AJRCCM 2000; 162: 1403

Modified Asthma Predictive Index (API)

Cough-variant asthma

Cough-variant asthma presents as dry

cough at night. It worsens with exercise

(EIA) and nonspecific triggers (cold air).

Cough-variant asthma responds to asthma

therapy with ICS.

Cough-variant asthma is diagnosed with

pulmonary function testing (PFTs) with

response to bronchodilator. The most

common cause of chronic cough in children

is cough-variant asthma.

Guidelines National Heart, Lung, and Blood Institute (NHLBI) guidelines

for diagnosis and management of asthma

Key concepts: - severity dictates therapy

- - distinction between intermittent and persistent asthma

- - "rule of 2s”

- - 4 levels of asthma severity - intermittent; 3 sublevels of

persistent

- - inhaled corticosteroids (ICS) preferred for all levels of

persistent asthma

- - use of asthma action plans

- - spirometry recommended

Rule of 2s

- if symptoms are present for more than 2 days per

week or for more than 2 nights per month, asthma

categorized as persistent.

- Within this category, disease must be classified as

mild, moderate, or severe. However, as severity of

asthma not constant, must monitor patients for

changes; as severity changes, therapy should

change too.

- The category of “mild intermittent” asthma was

eliminated in the 2007 guidelines - now it is just called

“intermittent” asthma.

- impairment - refers to symptoms

- - risk - refers to likelihood that the patient will eventually

have exacerbation of asthma and present to emergency

department (ED) or hospital, or need course of oral

corticosteroids

- - control - refers to the level of patient’s asthma control

The concepts of “impairment”, “risk”, and “control” were

introduced in the 2007 guidelines:

Classification of asthma severity

- impairment domain - daytime and nighttime symptoms

(rule of 2's), use of short-acting beta-agonist (SABA),

interference with normal activities

- - risk domain - number of exacerbations per year (if more

than 2, daily controller medication is needed). Increased

risk is conferred by parental history of asthma or history of

eczema.

- Childhood Asthma Control Test (ACT) is validated down to

age 4 yr. Adult ACT questionnaire should be used for

teenagers (cutoff age is 11 years).

Treatment steps

- step 1 - SABA as needed –

- step 2 - low-dose ICS monotherapy vs. leukotriene receptor

antagonist (LTRA)

- - step 3 - low-to-medium dose ICS plus long-acting beta-

agonist (LABA)

- - step 4 - high-dose ICS therapy plus LABA and (if needed)

systemic corticosteroids. Omalizumab (Xolair; anti-IgE

antibody) is prescribed before placing patient on daily oral

corticosteroids.

“Rule of 2s” to determine level of control

- daytime symptoms more than 2 days/wk

- rescue β2 -agonist use more than 2 times per week

- nighttime symptoms more than 2 nights/mo

- more than 2 rescue β2-agonist canisters/yr

Step Down or Step Up

When to step down therapy? If patient is well-controlled for

3 mo, consider stepping down therapy.

When to step up therapy? If the patient is not well-

controlled, step up therapy and re-evaluate in 2 to 6 wk. If the

patient is very poorly controlled, step up therapy 2 steps,

consider short course of steroids, and reassess in 2 wk.

When to consider long-term ICS treatment

- positive API and more than 3 wheezing episodes in

previous 12 mo lasting more than 1 day and affecting

sleep

- consistent requirement for SABA treatment (more than

2 times/wk, on average, over 1-2 mo); 2 exacerbations in

6 mo requiring oral corticosteroids

Treatmnt

Inhaled corticosteroid

Relative binding affinity for glucocorticoid receptor (GR):

mometasone = fluticasone > budesonide > triamcinolone.

Relative anti-inflammatory potency: mometasone =

fluticasone > budesonide = beclomethasone >

triamcinolone.

Severe asthma - differential diagnosis and management

Foreign Body Aspiration

Radiographic Signs of Pneumomediastinum

Subcutaneous emphysema

Thymic sail sign

Pneumoprecardium

Ring around the artery sign

Tubular artery sign

Double bronchial wall sign

Continuous diaphragm sign

Extrapleural sign

Air in the pulmonary ligament

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