What is a typical case presentation of asthma?
6 yo with six week history of persistent cough that is worse at night, with activity, and with exposure to cold. History of allergies and eczema. Family history of asthma.
What are key findings from the history of a child with asthma?
Recent history of URI, nasal congestion, cough worse at night, cough worse with activity and cold, history of eczema, positive family history of asthma.
What are key findings from the physical exam of a child with asthma?
Allergic shiners, clear nasal secretions, end-expiratory wheeze
What is on the differential diagnosis for asthma?
Asthma, bronchitis, sinusitis, allergies, habitual cough, atypical pneumonia, GERD
What are key findings from testing a child with asthma?
CXR: mild hyperinflation.
Spirometry: Mild, reversible obstructive defect.
A genetic predisposition - compounded by environmental factors - leads to the development of an IgE-mediated response (allergic rhinitis, asthma, and/or atopic dermatitis) to common inhalation allergens (including house dust mites, animal dander, and cockroaches, fungi, and some grass and ragweed pollens). Children of an atopic parent have a 30 percent risk for developing an atopic disorder and are more likely to become sensitized when exposed to allergens.
What is the epidemiology of asthma in children?
- Number of people affected by asthma has more than doubled in past 15 years
- Now most common pediatric chronic disease, afflicting nearly 5 million children less than 18 yrs in the US
- Accounts for 19 million missed school days, greater than 3 million physician visits, and 200,000 pediatric hospitalizations each year.
- More than 5,500 people die from asthma every year
What is the pathophysiology of asthma?
Biphasic inflammatory response:
- Early asthmatic reaction (first hour): Mast cells and eosinophils release mediators such as prostaglandins and leukotrienes, leading to increased vascular permeability, mucus hypersecretion, and rapid bronchoconstriction.
- Late asthmatic reaction (begins 2-3 hours later, reaches a maximum by about 4-8 hours and resolves in about 24 hours). Neutrophil, eosinophil, and lymphocyte infiltration of bronchial epithelium results in epithelial destruction, fibrotic remodeling, and hyperplasia of the bronchial smooth muscle. Increase in airway hyper responsiveness may persist for days to weeks after the late reaction appears to have resolved.
Diagnosis of asthma is based on the following:
- History (episodic nature, precipitating factors, and family history)
- Physical examination
- Pulmonary function testing before and after bronchodilator therapy
NIH/NAEPP classification of asthma severity:
This classification system is based on an algorithm combining frequency of symptoms, nocturnal symptoms, and PFT results. Asthma severity is classified as either:
-Intermittent (mild) or
-Persistent (mild, moderate, and severe)
Note: Two additional recognized clinical forms of asthma that are not included in this classification are exercise-induced asthma (severe bouts of bronchospasm triggered only by exercise or cold air) and cough-variant asthma (presents only with cough).
What is the epidemiology of primary pulmonary tuberculosis (TB)?
- In US, most children infected with Mycobacterium tuberculosis in the home by someone close to them
- Outbreaks may occur in daycare centers and schools
- Case rates for ages highest in urban, low-income areas and in foreign-born children, among whom more than two thirds of reported cases in the US now occur
- A diagnosis of TB in a young child is a public health sentinel event usually representing recent transmission
What are signs and symptoms of primary pulmonary tuberculosis (TB)?
- Most children have few to no symptoms, often in sharp contrast to the degree of radiographic changes
- Greater than 50 percent of infants and children with radiographically evident disease have no physical findings and are discovered only by contact tracing.
- Infants and toddlers are more likely to experience symptoms such as nonproductive cough, mild dyspnea, or wheezing (due to bronchial compression by enlarged regional lymph nodes).
- Infants may present with failure to thrive
- Severe cough and sputum production, together with systemic complaints such as fever, night sweats, and anorexia, usually signify intrapulmonary dissemination
- Systemic symptoms such as night sweats and weight loss are uncommon
Radiographic findings of tuberculosis:
- The hallmark of TB in the lung is the primary complex
- The size of hilar lymphadenopathy is relatively large compared with the size of the initial lung focus
- A sequence commonly seen is:
- -Hilar adenopathy (most common radiographic abnormality)
- -Focal hyperinflation
- -Atelectasis, with minimal evidence of the primary lung focus itself
- All lobar segments of the lung are at equal risk of initial infection
- Two or more primary foci are present in 25 percent of cases.
- Findings may be confused with foreign body obstruction
- Small local pleural effusions are common; large effusions rarely seen in children less than six years of age
How do you diagnose TB in a child without symptoms?
- Mantoux skin test is the only practical tool for diagnosing TB infection in an symptomatic child
- -Formerly called a PPD (purified protein derivative), now more correctly referred to as TST (tuberculin skin test)
- TST considered positive if it is:
- -Greater than 5 mm in high-risk children
- -Greater than 10 mm in moderate-risk children
- -Greater than 15 mm in low-risk children
How do you diagnose TB in a child with symptoms?
Culture of the M. tuberculosis organisms should be obtained from a sputum sample, or from a first morning gastric aspirate in young children
Environmental irritant, asthma, fungal infection
Productive, “wet” or “congested” cough
Lower respiratory infection
Croup, subglottic disease, or foreign body
Brassy or honking cough
habitual cough, tracheitis
Pertussis, chlamydia, mycoplasma, foreign body
Worse at night cough
Asthma, allergies, sinusitis
Disappears at night cough
Associated with gagging or choking cough
Precipitating factors such as cold or activity - cough
What does dysphonia or hoarseness suggest?
Laryngeal irritation from chronic rhinitis or gastroesophageal reflux.
Chest pain or palpitations:
True cardiac chest pain is rare in children. Substernal pain may suggest gastroesophageal reflux. Palpitations may suggest congestive heart failure.
Dyspepsia or regurgitation:
History of choking:
Foreign body aspiration or aspiration pneumonia (especially in children with neurologic impairment)
Dyspnea or wheezing:
Asthma, congestive heart failure
Fever or abdominal pain:
Frontal or orbital headaches may suggest sinusitis
Possibly due to post-nasal drip from allergies or sinusitis
Suggestive of allergies or sinusitis
Atopic diathesis - supports asthma or allergies
Increased anteroposterior (AP) diameter:
A hyper inflated thorax is a sign of air-trapping as seen in significant chronic obstructive lung disease.
Discontinuous fine or coarse sounds, typically inspiratory, generally associated with alveolar or small airway conditions such as pneumonia, pulmonary edema, bronchitis, or interstitial diseases.
Inspiratory to expiratory (I:E) ratio:
Normally = 1:2. Obstructive illnesses (i.e., asthma or cystic fibrosis) increase the I:E ratio of 1:3 to 1:4. Restrictive illnesses (uncommon in children) diminish the I:E ratio to 1:1.
Rhonchi (or coarse crackles):
Continuos, low-pitched sounds suggestive of secretions in the larger airways, such as with pneumonia or bronchitis.
Rales (or fine crackles):
Suggest secretions or early collapse of small airways, such as in pneumonia.
Abnormal retraction of the intercostal, supraclavicular, and subcostal spaces can be seen in children in significant respiratory distress.
High-pitched inspiratory noise that suggests partial obstruction of the larynx or trachea (extra thoracic airway). Stridor in children most often seen in croup, inhaled foreign body with partial obstruction and laryngotracheomalacia.
Suggests mediastinal mass, pneumothorax, or foreign body aspiration.
Continuous musical noises, typically expiratory, associated with a variable obstruction of small and moderate-sized airways (i.e., bronchi and bronchioles). Most commonly seen in asthma and bronchiolitis.
What are typical exam findings in atopic children?
Allergic (atopic) shiners, Dennie-Morgan lines, Allergic salute, Digital clubbing.
Allergic (atopic) shiners:
Darkening of the lower eyelids due to venous stasis
Creases under the lower eyelids from intermittent edema.
Transverse crease across lower nasal bridge from repeated upward rubbing of the nose (the salute) to relieve itching and obstruction.
Angle between nail plate and nail fold is increased above 180 degrees. Clubbing suggests chronic hypoxia.
What are the most likely differential diagnoses for asthma?
Asthma, allergies, sinusitis, bronchitis, atypical or viral pneumonia, gastroesophageal reflux disease (GERD), Habitual cough.
What are less likely differential diagnoses for asthma?
Pulmonary embolus (PE), cystic fibrosis, congestive heart failure, other causes of chronic cough.
Very common diagnosis in pediatrics. Nasal congestion is a prominent feature, resulting in nocturnal cough due to post-nasal drip. Personal and family history of atopic diathesis support this diagnosis. On physical exam may see allergic diners, clear nasal secretions, cobblestoning of the posterior pharynx (lymphoid hyperplasia from chronic post-nasal drip), and/or edematous turbinates.
Often preceded by a URI. Common complaint of nocturnal cough due to post-nasal drip. Signs and symptoms of sinusitis in younger children include bilateral purulent (yellow or green) nasal secretions lasting for more than one week, sore throat, fever, cough (esp. at night), malodorous breath, and irritability. Unilateral symptoms suggest a nasal foreign body. Symptoms of acute sinusitis in older children are similar to those in adults, including headache, facial pain and fever.
Acute bronchitis in children is believed to result from extension of viral inflammation into the lower respiratory tree. Complaint is of prolonged congested cough associated with URI symptoms. Cough usually equal during the day and nigher, with no change in symptoms due to exercise or change in air temperature. Rhonchi commonly heard on chest exam.
Atypical or viral pneumonia:
May present with sx similar to URI. Causes include influenza, adenovirus, mycoplasma, pertussis, human immunodeficiency virus, and fungi. Cough is equal throughout day and night but may be exacerbated by exercise or cold air. Cough may persist for 8-12 weeks. Rales, rhonchi, or wheezing sometimes heard. Hypoxemia and fever often present.
Gastroesophageal reflux disease (GERD):
Clinically significant GERD in children more commonly seen in infants and older children with neuromotor disease. Cough classically worse at night. Nasal reflux may result in congestion.
Cough perpetuated from cough begun with a viral URI. Irritation of the airway leads to stimulation to cough. Typically a loud, short, dry, brassy, spasmodic cough unchanged by exercise or temperature. Classically resolves during sleep.
Pulmonary embolus (PE):
Risk factors include hyper coagulable state, recent immobilization, or family history.
Unlikely in an otherwise healthy children with no past history of chronic infections or growth failure. Nasal polyps may be seen on physical exam. Most commonly seen in caucasian population.
Congestive heart failure:
Causes of acquired congestive heart failure, such as myocarditis, may present with cough and wheeze. Additional symptoms such as shortness of breath, palpitations, and fatigue are usually present as well.
Causes of chronic cough (i.e. lasting greater than 4 weeks) in infants and toddlers:
Many causes including infection, inflammation, irritation, anatomic, psychogenic, or from a cardiac or GI condition. Infants are more likely to have anatomic malformations, such as: -Congenital vocal cord dysfunction -Laryngotracheomalacia -Vascular ring -Laryngeal web -Tracheal stenosis -Tracheoesophageal fistula In toddlers, a foreign body must be considered.
What is hyperinflation consistent with on a CXR?
Asthma or cystic fibrosis.
Spirometry (pulmonary function testing):
- The most sensitive diagnostic test in children old enough to perform the test (around 5-6 years)
- Testing before and after bronchodilator therapy is the most specific means of determining presence of reversible obstructive airway disease (most commonly asthma)
- Bronchoprovocation (using methacholine, histamine, or exercise challenge) is reserved for cases in which asthma is suspected but spirometry is normal or near normal. Should be performed by trained individuals.
- Relationship of forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) is the key to differentiating obstructive lung disease from restrictive lung disease:
- -Obstructive lung diseases (asthma and cystic fibrosis) is characterized by a reduction in airflow and trapping of air inside the thorax behind tight, plugged airways, lowering the FEV1. Obstruction results in a low FEV1/FVC ratio.
- -Restrictive lung disease (much less common in children) is also characterized by a low FEV1, but a proportionate reduction in the FVC maintains a normal FEV1/FVC ratio.
What is the stepwise approach to treatment of asthma?
- Using the NIH/NAEPP guidelines, assign patient to most severe step in which any feature occurs.
- Gain control as quickly as possible.
- Step down to the least medication necessary to maintain control.
What are the four main asthma medications?
Beta2-agonists (short and long acting), Inhaled corticosteroids, Leukotriene receptor antagonists and leukotriene-synthesis inhibitors, Oral antihistamine
Beta2-agonists (short and long acting):
- Primary medication for patients with mild intermittent disease and exercise-induced bronchospasm
- Short-acting beta agonists serve as rescue medications in patients with persistent disease
- Minimize use of short-acting inhaled beta2-agonists. Over-reliance on these medications (eg use of approximately one canister a month even if not using it every day) indicates inadequate control of asthma and the need to initiate or intensify long-term control (maintenance) therapy.
- Used in all patients with persistent asthma as daily prophylaxis
- Diminishes need for systemic steroids
- Inhaled steroids require several weeks of daily use before the beneficial effects are realized
- Monitor children receiving long-term therapy for elevation in blood pressure, serum blood sugar, growth delay, and cataract development. Varicella status should be checked and immunization given if needed.
Leukotriene receptor antagonists and leukotriene-synthesis inhibitors:
- These agents block the inflammatory pathway response to the inhaled allergen.
- In chronic asthma, they can allow for reduced doses of inhaled corticosteroids, but these meds are less effective than steroids and not recommended as mono therapy
- Antihistamines (H1 antagonists) are safe and effective for controlling sneezing, nasal pruritis, and rhinorrhea associated with intermittent or short-term allergies.
- Newer antihistamines are significantly less sedating than the earlier ones
Metered-dose inhalers (MDIs):
- Portable, lightweight, and inexpensive
- Disadvantages are the high speed of medication delivery (upward of 400 miles/hr, leading to impaction of almost 99 percent of the medication on the back of the throat) and the need to coordinate a breath with medication delivery.
- Should be used in all children (and many adults)
- Medication is suspended within the device and may be inhaled either through the mouth as a single breath or with multiple tidal breathes with equal effect
- When used for inhaled corticosteroids, spaces have the added benefit of preventing side effects from MDIs such as dysphonia and oral thrush.
Peak expiratory flow (PEF) measured using a handheld peak flow meter is a simple, objective, and reproducible measure of existence and severity of airflow obstruction. PEF is used for short-term monitoring, managing exacerbations, and in daily long-term monitoring in moderate to severe asthma.