Chapter 32 Foreign Body: Ingestion and Aspiration ) Foreign-body aspiration is typically seen in toddlers, although older infants may aspirate solid food particles or small objects placed within their reach Rarely, an older child may also aspirate food particles or other objects The aspiration of a small object or food substance may not be witnessed, and thus, may go unrecognized for weeks or months until persistent lower respiratory symptoms (e.g., persistent cough, wheezing, possibly recurrent fever) trigger a search for an underlying cause Evaluation often shows an area of consolidation and/or collapse on radiograph If aspiration history is not known and the patient is treated for routine pneumonia, the symptoms typically fail to resolve despite seemingly appropriate medical therapy TABLE 84.1 LIFE-THREATENING CAUSES OF WHEEZING Asthma Bronchiolitis Foreign-body aspiration Pulmonary hemorrhage Mediastinal tumor Congestive heart failure Chemical pneumonitis Anaphylaxis Recurrent aspiration of food or gastric contents is usually seen in infants younger than year of age, or in older patients with severe intellectual disability or neuromuscular disease Disordered swallowing and gastroesophageal (GE) reflux typically contribute in varying degrees to the recurrent aspiration that occurs in these patients Repeated aspiration is also seen in children with tracheostomies and in children with structural anomalies of the tracheolaryngeal complex or an H-type tracheoesophageal fistula, which is rare Patients with chronic recurrent aspiration may develop wheezing and respiratory distress in the absence of a well-defined episode of choking or severe coughing because many such patients have depressed cough reflexes or experience “microaspiration.” Fever often accompanies pulmonary aspiration, reflecting associated chemical inflammation or infection of the tracheobronchial tree Wheezing attributable to anaphylaxis is also of sudden onset and may be accompanied by one or more other clinical findings including urticaria, angioedema, stridor, hypotension, abdominal pain, vomiting, and diarrhea When wheezing is the only finding, anaphylaxis may be suspected when the onset of respiratory difficulty is associated with Hymenoptera envenomation, medication or food ingestion, or another allergic precipitant Wheezing in this context typically responds promptly to epinephrine administration and/or to bronchodilator therapy The development of chronic respiratory problems in the neonatal period, due to complications such as prematurity, assisted ventilator support, and oxygen dependence, all leads to a common condition referred to as CLD This condition is the childhood equivalent of chronic obstructive pulmonary disease and represents a pathophysiologic continuum that includes varying degrees of structural damage and airway inflammation Although gradual improvement in lung function occurs during infancy and early childhood, bronchial hyperactivity and recurrent episodes of wheezing may persist until later in childhood Transient wheezing may also occur with smoking and air pollutant exposures It is important to note that 90% of cigarette smokers start before the age of 21 years Wheezing and bronchiolitis have also been associated with passive smoke exposure Air pollution containing particulate matter less than or equal to 10 microns in diameter, which is small enough to travel into the distal airways, nitrogen dioxide, nitrogen oxide, and carbon monoxide have been associated with wheezing, and can exacerbate other causes of wheezing TABLE 84.2 CLINICAL CLASSIFICATION OF WHEEZING: AGE AT DIAGNOSIS AND DISEASE PREVALENCE Disease 3 yrs Common Bronchiolitis Asthma Pneumonia Asthma Pulmonary aspiration Anaphylaxis CLD Anaphylaxis Bronchiolitis Less Pneumonia common Pulmonary aspiration GE reflux CLD Rare Swallowing disorders Congenital heart disease CLD Smoking/air pollution Psychogenic wheezing (vocal cord dysfunction) Tracheobronchomalacia Mediastinal Mediastinal lymphadenopathy lymphadenopathy Cystic fibrosis Congenital heart Cystic fibrosis disease Immunodeficiency Cystic fibrosis Immunodeficiency Tracheoesophageal Sarcoidosis Tuberculosis fistula Cystic malformations GE reflux Sarcoidosis of lung Primary ciliary Bronchiectasis Bronchiectasis dyskinesia Vascular rings/slings Pulmonary edema Pulmonary edema Congenital lobar Parasitic infections Pulmonary emphysema aspiration Parasitic and fungal infections GE, gastroesophageal; CLD, chronic lung disease Rare Conditions Immunodeficiency Pneumonia