Pulmonology

1

How common is allergic rhinitis?

Very common . Ten percent to 30% of children and adults in the developed world experience allergic rhinitis, which is the most common manifestation of allergic disease and one of the most common chronic diseases of childhood.

2

In addition to chronic or recurrent nasal congestion, what features on history and physical examination suggest allergic rhinitis?

• “Allergic facies”: Open mouth, midface hypoplasia

• “Allergic nasal crease”: Nasal crease on bridge of the nose as a result of chronic upward rubbing with the palm of the hand (the “allergic salute”)

• Diminished sense of taste and smell

• Dental malocclusion

• Allergic “shiners” (dark circles under the eyes)

• Multiple infraorbital folds

• Cobblestoning of the posterior oropharynx ( Fig. 16.1 )

  

• Pale, boggy appearance of the nasal mucosa

3

What are three early-life risk factors for allergic rhinitis?

• Male gender (females have a higher incidence of rhinitis in adulthood)

• Not having early contact with siblings at home or children in day care

• Not having early contact with pets or not living on a farm

4

How does the time of year help identify the potential cause of allergic rhinitis?

Tree pollen is usually associated with the onset of the growing season. After local tree pollination, grass pollens appear; this may occur earlier in locales where there are short winters. Weed pollen other than ragweed is associated with the late-summer pollen peak. In the autumn, ragweed is the major pollen allergen. It pollinates from mid-August until the first freeze in most of the United States. Counts are especially high in eastern and central North America. Fungal aeroallergens span the growing season. Relative concentrations of household animal allergens, dust mites, and indoor fungi generally increase when doors and windows are closed. However, dust mites and molds proliferate in areas of high humidity and may cause perennial symptoms.

5

When are allergy blood tests used?

• A patient is taking a medication that blocks allergy skin testing, such as an antihistamine that cannot be stopped for at least 3 days.

• A patient has a skin condition such as eczema or psoriasis without sufficient unaffected areas to do skin testing.

• Blood testing would be better tolerated, such as in an infant or young child.

6

What are the pros and cons of skin testing versus in vitro testing (i.e., quantification of allergen-specific immunoglobulin E [IgE] in patient’s serum) for allergies?

In vitro tests

• No risk for anaphylaxis

• Results not influenced by medications (e.g., antihistamines), dermatographism, or extensive dermatologic disease

• More costly

• Better predictive value for some common food allergens

Skin testing

• Less costly

• More sensitive than in vitro tests

• Results immediately available

7

What are the recommended treatments for children with allergic rhinitis?

• Environmental control measures for allergen avoidance are the mainstay of treatment. Relevant allergens are recommended for exposure reduction on positive skin or serum-specific IgE testing correlated with the presence of symptoms on allergen exposure.

• Pharmacotherapy , including nasal corticosteroid sprays, antihistamines (given orally or by nasal spray), oral antileukotrienes, or combinations of these medications are effective treatments.

• Immunotherapy is reserved for those with persistent symptoms despite the previous treatment and for those who want control of symptoms with fewer medications.

8

What are the major indoor (year-round) allergens?

House dust mites (HDMs), animal dander , cockroach , and molds .

9

How can HDM concentrations be minimized?

Allergens from HDMs are among the most common triggers for allergic rhinitis and asthma. They are found throughout homes, but accumulate in bedding, soft furnishings, and carpet. HDM allergen reduction methods include the following:

• Encasing pillows, mattresses, and box springs in allergen-proof, zippered covers (plastic or fine woven fabric). Although not effective as a single measure, there is evidence these covers may be of benefit when used as part of an extensive bedroom-based dust mite allergen reduction program.

• Bedding may be washed in hot (131°F [55°C]) water. Drying the bedding in high heat in a dryer is an alternative that may prevent scalding injuries in children from having the water heater temperature raised above 120°F (50°C).

• Humidity should be reduced indoors to ≤ 45% using a dehumidifier and/or air conditioning with the windows closed.

• Wall-to-wall carpeting should be removed as much as possible and replaced with throw rugs. These should be regularly washed or dry-cleaned.

10

How can you decrease cat allergen in the home?

• Remove upholstered furniture, carpet, and other sources harboring the allergen.

• Use high-efficiency particulate air (HEPA) filters and vacuum cleaners.

• Wash the cat regularly if feasible.

• Consider a “felinectomy.”

11

Is there truly a dog breed that is “hypoallergenic”?

Alas, the hypoallergenic dog appears to be a myth . Although certain dogs (e.g., poodles, Spanish waterdogs, Airedale terriers, and a hybrid, the Labradoodle) are commonly marketed as “hypoallergenic,” comparison of the quantity of the dog allergen (Can f 1, an allergen specific to dogs) in hair and coat samples and in the surrounding surface environment found no differences compared with control breeds. In the United States, about 78 million dogs occupy homes, so this is not good news to the 20% of the general population who may be allergic to dogs.

12

Which children should be considered for immunotherapy?

Allergen immunotherapy is an effective treatment for allergic rhinitis, asthma, and the prevention of venom anaphylaxis. It also may be of benefit in atopic dermatitis. For allergic rhinitis and allergic asthma, immunotherapy should be considered in patients who (1) are not well controlled despite attempts at allergen exposure reduction and pharmacotherapy or (2) in patients who wish to take less medication. Subcutaneous or sublingual routes (for certain inhalant allergens) are approved in the United States. In children, immunotherapy has been shown to prevent the progression of allergic rhinitis to asthma and may prevent sensitization to new allergens in monosensitized individuals.

13

How common is exercise-induced bronchoconstriction (EIB) in children with allergic rhinitis?

Exercise is a trigger of bronchoconstriction in 40% to 50% of children with allergic rhinitis compared with 90% of those diagnosed with asthma and 10% of those not known to have asthma or respiratory allergies. EIB (also known as exercise-induced bronchospasm ) is defined as a 10% drop in FEV ₁ from the value before exercise.

14

What are the major determinants of asthma?

• Innate immunity : intrinsic tendency of individual immune system to respond in a certain pattern; specifically to produce Th2 cytokines rather than Th1 in response to a given stimulus

• Genetics : asthma has a heritable component, but the genetics are complex; although several loci have been implicated, none account for a substantial proportion of disease

• Environmental : two major factors have been identified in the development and persistence of asthma: aeroallergens (particularly sensitization and exposure to dust mites and Alternaria mold) and viral infections (e.g., respiratory syncytial virus [RSV], rhinovirus). Other, less well-established environmental influences in the development of asthma include tobacco smoke, air pollution, and obesity.

15

When does asthma usually have its onset of symptoms?

About 50% of childhood asthma develops before the age of 3 years, and nearly all has developed by the age of 7 years. The signs and symptoms of asthma, including chronic cough, may be evident much earlier than the actual diagnosis, but may be erroneously attributed to recurrent pneumonia.

16

Which children with wheezing at an early age are likely to develop chronic asthma?

Although about one-third of children will have an episode of wheezing before they are 1 year of age, most (80%) do not develop persistent wheezing after age 3 years. Risks factors for persistence include the following:

• Positive family history of asthma (especially maternal)

• Increased IgE levels

• Atopic dermatitis

• Rhinitis not associated with colds

• Secondhand smoke exposure

17

What historical points are suggestive of an allergic basis for asthma?

• Seasonal nature with concurrent rhinitis (suggesting pollen)

• Symptoms worsen when visiting a family with pets (suggesting animal dander)

• Wheezing occurs when carpets are vacuumed or bed is made (suggesting mites)

• Symptoms develop in damp basements or barns (suggesting molds)

18

What are other potential triggers for asthma?

• Upper airway infections (rhinitis, sinusitis)

• Cold air

• Weather changes

• Exercise

• Environmental (pollutants, cigarette smoke)

• Irritants (strong odors, paint fumes, chlorine)

• Emotional extremes (stress, fear, crying, laughing)

• Medications (nonsteroidal anti-inflammatory drugs, aspirin, beta blockers)

• Foods, food additives

• Gastroesophageal reflux disease

• Hormonal (menstrual, premenstrual)

19

What is the time course of EIB?

EIB is condition in which there is an acute onset of bronchoconstriction that typically occurs after (sometimes during) exercise. Five percent to 20% of the general population may have EIB compared with up to 90% of those diagnosed with symptomatic persistent asthma. Symptoms are most commonly cough (although these can include wheezing, chest tightness, and unusual shortness of breath or excess mucus) with a peak 5 to 10 minutes after the conclusion of exercise and with resolution within 30 to 60 minutes.

20

How is EIB diagnosed?

Exercise challenge is the preferred method. EIB is likely if the peak flow rate or FEV ₁ drops by 10% after 6 minutes of vigorous exercise, either in a laboratory or field setting. This exercise can include jogging on a motor-driven treadmill (15% grade at 3 to 4 mph), riding a stationary bicycle, or running up and down a hallway or around a track in field testing. The greatest reduction in FEV ₁ is usually seen 5 to 10 minutes after exercise. As further verification of the diagnosis, if the patient has developed a decreased peak flow (and possibly wheezing), two puffs of a beta-2 agonist should be administered to attempt to reverse the bronchospasm.

21

What is the likely mechanism that causes EIB?

The leading theory is an osmotic one. Increased ventilation during the hyperventilation of exercise (especially in dry air) causes water loss from airway surfaces through evaporation. This reduction in epithelial liquid volume causes osmotic changes, which in turn lead to mast cell degranulation. Mast cells release prostaglandins (especially prostaglandin D2), leukotrienes, histamine, and tryptase. Many of these are signaling molecules, which mediate airway smooth muscle contraction and increase mucus production, microvascular permeability, and sensory nerve activation. The release of these mast cell components, initially generated by osmotic changes, are thought to be the main stimulus for bronchoconstriction and airway edema.

22

What are other bronchoprovocation tests for assessing airway reactivity?

• Eucapnic voluntary hyperventilation (EVH) involves breathing a dry gas at an increased respiratory rate in an effort to induce bronchospasm and a decrease of FEV ₁ of > 10%.

• Pharmacologic challenge by inhalation of agents that act on smooth muscle (e.g., methacholine or histamine) or osmotic provocation (mannitol). The threshold concentration required to induce bronchospasm (decline in FEV ₁ by 20%) is determined and compared with that required in healthy controls.

• Antigen challenge can be used for specific identification of a suspected allergen or occupational trigger. This is done only at specialized centers and may require prolonged observation (> 24 hr) to identify and potentially treat a late-phase response.

• Aspirin challenge is performed in patients with suspected aspirin-exacerbated respiratory disease (AERD) who have a medical indication for treatment with aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs).

23

A 15-year-old with repeated shortness of breath after track practice has suspected EIB, but pulmonary function tests are normal, bronchoprovocation testing is negative, and he has no response to treatment with asthma medications. What is a likely alternative?

Exercise-induced laryngeal obstruction (EILO). This group of diagnoses includes vocal cord dysfunction and exercise-induced laryngomalacia . In the former, during exercise, the vocal cords adduct during inspiration to cause shortness of breath, chest tightness, cough, or stridor. In the latter, there is inspiratory prolapse of supraglottic structures, which causes dyspnea and/or stridor. In both cases, there is paradoxical laryngeal motion—narrowing occurs when a bigger breath is taken. The precise reasons are unclear but may be related to smaller airway dimensions, inhibition of laryngeal reflexes, or impaired innervation and/or power of the laryngeal muscles. The gold-standard test for diagnosis is flexible nasoendoscopy with continuous video recording of the larynx throughout exercise.

24

What mechanisms lead to airway obstruction during an acute asthma attack?

The main causes of airflow obstruction in acute asthma are airway inflammation , including edema , bronchospasm , and increased mucus production . Chronic inflammation may eventually result in airway remodeling, which may not be clinically apparent without pulmonary function testing.

25

All that wheezes is not asthma. What are other noninfectious causes?

• Aspiration pneumonitis: especially in a neurologically impaired infant or an infant with gastroesophageal reflux, and especially if there is coughing, choking, or gagging with feedings. If there is a clear association with feedings, consider the possibility of a tracheoesophageal fistula.

• Bronchiolitis obliterans: chronic wheezing often after infection (e.g., Mycoplasma or viral illnesses, especially adenovirus)

• Bronchopulmonary dysplasia: especially if there has been prolonged oxygen therapy or a ventilatory requirement during the neonatal period

• Ciliary dyskinesia: especially if recurrent otitis media, sinusitis, or situs inversus is present

• Congenital malformations: including tracheobronchial anomalies, tracheomalacia, lung cysts, and mediastinal lesions

• Cystic fibrosis (CF): if wheezing is recurrent and associated with failure to thrive, chronic diarrhea, or recurrent respiratory infections

• Congenital cardiac anomalies: especially lesions with large left-to-right shunts

• Foreign-body aspiration: if associated with an acute choking episode in an infant > 6 months

• Vascular rings, slings, or airway compression

26

How is the severity of an acute asthma attack estimated?

See Table 16.1 .

27

Is a chest radiograph necessary for all children who wheeze for the first time?

A chest radiograph should be considered for a first-time wheezing patient in the following situations:

• Findings on physical examination that may suggest other diagnoses

• Marked asymmetry of breath sounds (suggesting a foreign-body aspiration)

• Suspected pneumonia

• History suggestive of foreign-body aspiration

• Hypoxemia or marked respiratory distress

• Older child with no family history of asthma or atopy

• Suspected congestive heart failure (CHF)

• History of trauma that may have caused injury to the airway (e.g., burns, scalds, blunt or penetrating injury)

28

What are the usual findings on arterial blood gas sampling during acute asthma attacks?

The most common finding is hypocapnia (i.e., low Pa co ₂ ) because hypoxemia intensifies respiratory drive, resulting in hyperventilation (unless the child is being treated with oxygen). Hypercapnia is a serious sign that suggests the child is nearing respiratory failure. This finding should prompt consideration of ventilatory support by noninvasive means (bilevel positive airway pressure [BiPAP]) or endotracheal intubation and mechanical ventilation.

29

What are the indications for hospital admission in children with asthma?

After therapy in the emergency department, admission is advisable if a child has any of the following:

• Depressed level of consciousness

• Incomplete response with moderate retractions and/or wheezing, peak flow of < 50% predicted, pulsus paradoxus of > 15 mm Hg, Sa o ₂ of ≤ 90%, Pa co ₂ ≥ 42 mm Hg

• Breath sounds diminished significantly

• Evidence of dehydration

• Pneumothorax

• Residual symptoms and history of severe attacks involving prolonged hospitalization (especially if intubation was required)

• Parental unreliability

An equally difficult (and very unpredictable) challenge relates to predicting which patients will relapse after responding to therapy and subsequently require hospitalization. This is a major problem because rates of relapse in asthma can approach 20% to 30%.

30

What are the possible acute side effects of albuterol and other beta agonists?

• General: hypoxemia, tachyphylaxis

• Renal: hypokalemia

• Cardiovascular: tachycardia, palpitations, premature ventricular contractions, atrial fibrillation

• Neurologic: headache, irritability, insomnia, tremor, weakness

• Gastrointestinal: nausea, heartburn, vomiting

31

What is the role of magnesium sulfate in acute asthma attacks?

Magnesium sulfate is a known smooth muscle relaxant most commonly used in the treatment of preeclampsia. In asthmatic patients, when used in conjunction with standard bronchodilators and corticosteroids, intravenous magnesium sulfate can provide additional bronchodilation, with a reduced likelihood of hospital admission. It is most commonly used when severely ill patients have failed to respond to conventional therapy. Inhaled magnesium sulfate as an adjuvant therapy in children is currently under study. Adult studies have demonstrated significant improvements in respiratory function and lower hospital admission rates.

32

How is chronic asthma severity classified among children 5 to 11 years of age?

The National Heart, Lung, and Blood Institute and National Asthma Education and Prevention Program (NAEPP) define severity in terms of impairment and risk. Four categories are listed: intermittent , mild persistent , moderate persistent , and severe persistent . Categorization, which is also separately done for 0 to 4 years and ≥ 12 years, helps guide therapy ( Table 16.2 ).

Table 16.2

Classifying Asthma Severity and Initiating Therapy in Children

Adapted from the National Asthma Education and Prevention Program: Expert panel report III: Guidelines for the diagnosis and management of asthma. Bethesda, MD: National Heart, Lung, and Blood Institute, 2007. (NIH publication no. 08-4051).

Components of Severity		Classifying Asthma Severity and Initiating Therapy in Children
			Persistent
		Intermittent		Mild		Moderate		Severe
		Ages 0-4	Ages 5-11	Ages 0-4	Ages 5-11	Ages 0-4	Ages 5-11	Ages 0-4	Ages 5-11
Impairment	Symptoms	≤ 2 days/week		> 2 days/week but not daily		Daily		Throughout the day
	Nighttime awakenings	0	≤ 2 ×/month	1-2 ×/month	3-4 ×/month	3-4 ×/month	> 1 ×/week but not nightly	> 1 ×/week	Often 7 ×/week
	Short-acting beta-2 agonist use for symptom control	≤ 2 days/week		> 2 days/week but not daily		Daily		Several times per day
	Interference with normal activity	None		Minor limitation		Some limitation		Extremely limited
	Lung function	N/A	Normal FEV 1 between exacerbations	N/A	> 80% >80%	N/A	60%-80% 75%-80%	N/A	< 60% <75%
	FEV 1 (predicted) or peak flow (personal best) FEV 1 /FVC		> 80% >85%
Risk	Exacerbations requiring oral systemic corticosteroids (consider severity and interval since last exacerbation)	0-1/year		≥ 2 exacerbations in 6 months requiring oral synthetic corticosteroids or ≥ 4 wheezing episodes/1 year lasting > 1 day and risk factors for persistent asthma.	≥ 2 ×/year (see notes) Relative annual risk risk may be related to Fev 1

FEV _1, Forced expiratory volume in 1 second; FVC, forced expiratory capacity; ICS, inhaled corticosteroids; ICU, intensive care unit; N/A, not applicable.

33

What is the first-line pharmacologic treatment for patients with persistent asthma?

Inhaled corticosteroids. Daily administration significantly improves symptoms, reduces exacerbations, and allows healing of the chronic inflammatory changes that have taken place in the airways over time. Dosing and the use of adjunctive medications (e.g., long-acting inhaled beta-2 agonists, leukotriene-receptor antagonists) depend on frequency and severity of symptoms and exacerbations.

34

What are the four main components of optimal asthma care?

According to the NAEPP, optimal asthma care should cover all of the following domains:

• Assessment and monitoring of symptoms

• Education

• Control of environmental factors and comorbidities

• Review and adjustment of medications

35

Do inhaled steroids affect growth in children?

Results are conflicting but tend to indicate that mild growth suppression occurs among children receiving moderate to high doses, particularly in children with more severe asthma and primarily during the first year of therapy (about 1 cm). The reduction in growth is generally not progressive. It is important that children who require the extended use of inhaled steroids are monitored for height and height velocity and for cataracts.

36

What is anti-IgE treatment for asthma?

Omalizumab is a humanized monoclonal anti-IgE antibody approved for adjunctive therapy of severe persistent asthma in patients aged 6 years and older with an elevated total IgE and sensitivity to perennial allergens. It prevents free serum IgE from binding to its high-affinity receptors on mast cells and basophils. Omalizumab has been shown to reduce asthma exacerbations. It should be considered as an add-on for children > 6 years of age who have inadequately controlled, severe, persistent allergic IgE-mediated asthma who require continuous or frequent oral corticosteroids. Rarely, symptoms of anaphylaxis may develop up to 24 hours after administration, so the clinician administering the drug should be prepared to treat anaphylaxis, and the patient should carry self-injectable epinephrine for 1 day after administration.

37

Is there a role for complementary and alternative medicines in the treatment of asthma?

There are no clear directions or guidelines for the use of complementary and alternative medicines for children with asthma, although these therapies are often independently used by families. Hypnosis, yoga, relaxation techniques, acupuncture, and massage have shown benefit in some studies, but a review of studies involving mind–body techniques, relaxation, manual therapies, and diet has found a tendency to little or no significant difference between sham (placebo) and active therapy.

38

Is a nebulizer more effective than a metered-dose inhaler (MDI) with a spacer for the treatment of asthma?

For the treatment of exacerbations of asthma, nebulizers are primarily used in children < 2 years of age because of the ease of administration. Although an MDI with a spacer is used more commonly among older children, several studies in emergency rooms indicate that they are equally or more effective than nebulizers among young children, even those with moderate or severe acute asthma. Furthermore, the MDI with a spacer requires less treatment time, has fewer side effects, and often preferred by patients and parents. Children < 5 years typically require a facemask attached to the MDI/spacer device.

39

How useful are pulmonary function tests when evaluating and following children with asthma?

Spirometry is used for both the diagnosis and monitoring of asthma in children ≥ 5 years of age. The diagnosis of asthma requires airflow obstruction with at least a 12% improvement, or reversibility, in FEV ₁ from baseline with the inhalation of a short-acting beta agonist. Patient history and physical examination do not adequately predict the degree of a patient’s airflow obstruction. Spirometry is also used to monitor asthma after diagnosis and treatment. The goals of asthma therapy include normal or near-normal lung function with treatment. Spirometry should be performed on the patient after treatment has been initiated or changed, based on abnormal lung function, to assess improvement. It should also be performed during periods of prolonged loss of asthma control. Otherwise, in symptomatically controlled patients, it should be repeated at least yearly to monitor the patient long term. Handheld peak flow measurements are useful for monitoring patients, but not for initial diagnosis.

40

What proportion of children with asthma “outgrow” their symptoms?

Popular pediatric teaching has been that most children with asthma outgrow their symptoms. However, studies suggest that this is erroneous, and that only 30% to 50% become free of symptoms, primarily those with milder disease. Many children who appear to outgrow symptoms have recurrences during adulthood. Studies also indicate that many infants who wheeze with viral infections and are asymptomatic between illnesses tend to outgrow their asthma. Children with (1) early-onset asthma (age < 3 years) with a positive parental history for asthma, (2) atopic dermatitis, or (3) sensitization to aeroallergens are more likely to have persistent or recurrent bronchospasm. Although the overall trend is for asthma to become milder, a large percentage of adults have persistent obstructive disease, both recognized and unrecognized.

41

What diagnosis should be considered in a patient with poorly controlled asthma with recurrent infiltrates who has central bronchiectasis on a chest computed tomography (CT) scan along with peripheral blood eosinophilia?

Allergic bronchopulmonary aspergillosis . This is a T-cell–mediated hypersensitivity response to Aspergillus fumigatus (a ubiquitous fungus) that can cause migrating pulmonary infiltrates and central bronchiectasis. The condition occurs as a complication primarily in patients with asthma and CF. Diagnosis relies on an abnormal chest radiograph and CT scan, skin prick reactivity to A. fumigatus , elevated total serum IgE > 417 IU/L, and positive serum antibodies to A. fumigatus (IgE and/or IgG).

42

What are the typical features of bronchiolitis?

Bronchiolitis is a clinical diagnosis, identifying a syndrome that occurs in children under 2 years of age, characterized by upper respiratory symptoms (rhinorrhea), usually with fever, followed by lower respiratory tract signs (tachypnea, wheezing, crackles). This is typically caused by infection with a viral pathogen. In young children, the presentation may overlap with recurrent virus-induced wheezing and asthma.

43

What are the most common causes of bronchiolitis?

Respiratory syncytial virus (RSV ) is estimated to cause 50% to 80% of cases of bronchiolitis in children. Up to 100,000 children are hospitalized annually in the United States as a result of this pneumovirus, which is different from—but closely related to—the paramyxoviruses. Disease most commonly occurs during outbreaks in winter or spring in the United States and during the winter months of July and August in the Southern Hemisphere. In the first 2 years of life, 90% of children will become infected with RSV and up to 40% will develop some lower respiratory disease. Other agents responsible for bronchiolitis include human metapneumovirus (second most common cause), parainfluenza virus, influenza virus types A and B, adenovirus, rhinovirus, and coronavirus.

44

What are the predictors of severe bronchiolitis?

The single best predictor at an initial assessment appears to be oxygen saturation , which can be determined by pulse oximetry. An Sa o ₂ of < 95% correlates with more severe disease; a low Sa o ₂ is often not clinically apparent, and objective measurements are necessary. An arterial blood gas with a Pa o ₂ ≤ 65 mm Hg or a Pa co ₂ of > 40 mm Hg is particularly worrisome. Other predictors of increased severity include the following:

• An ill or “toxic” appearance

• History of prematurity (gestational age < 34 weeks)

• Atelectasis on chest radiograph

• Respiratory rate of > 60 breaths per minute

• Infant < 3 months old

• Presentation with apnea

45

What are the typical findings on a chest radiograph in a child with bronchiolitis?

The picture is varied . Most commonly, there is hyperinflation of the lungs. About 25% of hospitalized infants have atelectasis or infiltrates. Bilateral interstitial abnormalities with peribronchial thickening are common, or patients may have lobar, segmental, or subsegmental consolidation that can mimic bacterial pneumonia. Bacteremia or secondary bacterial pneumonia, however, is unusual in patients with bronchiolitis. With the possible exception of atelectasis, the chest radiograph findings do not correlate well with the severity of the disease. American Academy of Pediatrics (AAP) clinical practice guidelines recommend against routine chest x-rays for evaluation of infants presenting with classic features of bronchiolitis, as unnecessary chest x-rays contribute to health care costs, radiation exposure, and antibiotic overuse and provide no clinical benefit. However, radiography in the evaluation of bronchiolitis continues to be overused.