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
40