Pediatric Respiratory Conditions: Clinical History and Diagnostic Findings

Pediatric Respiratory Condition

This app is a comprehensive collection of pediatric respiratory conditions, carefully organized with specific clinical diagnostic findings. It serves as a valuable tool for medical students and pediatricians, helping them identify, differentiate, and understand various respiratory illnesses in children. Each condition is presented with key examination features, aiding in accurate and timely diagnosis.

With detailed clinical insights, this app enhances learning and supports clinical practice by providing up-to-date and practical information on pediatric respiratory conditions. Whether used for study purposes or as a reference in clinical settings, it helps streamline the diagnostic process and improves patient care outcomes.

1. Acute Bronchiolitis

Acute Bronchiolitis

Clinical History: Typically affects infants under 2 years, with peak incidence at 3-6 months. Usually begins with rhinorrhea and low-grade fever, progressing to cough, tachypnea, and increased work of breathing over 2-3 days. Often preceded by exposure to individuals with upper respiratory infections. Seasonal pattern with peak in winter months.

Diagnostic Findings: Tachypnea, nasal flaring, subcostal and intercostal retractions. Auscultation reveals diffuse fine crackles and/or high-pitched wheezes. Hyperinflation of the chest may be observed. Pulse oximetry may show hypoxemia. Viral testing (e.g., rapid RSV antigen) often positive.

2. Pneumonia (Community-Acquired)

Pneumonia (Community-Acquired)

Clinical History: Acute onset of fever, cough (often productive in older children), dyspnea, and sometimes pleuritic chest pain. May be accompanied by fatigue, decreased appetite, and abdominal pain. History of exposure to sick contacts or recent travel can be relevant. Vaccination status important to assess risk for specific pathogens.

Diagnostic Findings: Tachypnea (WHO criteria based on age), fever, decreased breath sounds, crackles, or bronchial breath sounds on auscultation. Dullness to percussion over affected area. Chest radiograph showing lobar consolidation, patchy infiltrates, or interstitial patterns. Laboratory findings may include elevated white blood cell count, C-reactive protein, and procalcitonin.

3. Asthma

Asthma

Clinical History: Recurrent episodes of wheezing, shortness of breath, chest tightness, and coughing, particularly at night or early morning. Symptoms often triggered by viral infections, exercise, allergens, or irritants. Family history of asthma or atopy is common. Pattern of symptoms worsening seasonally or with environmental changes.

Diagnostic Findings: During exacerbations: wheezing on auscultation, prolonged expiratory phase, use of accessory muscles, tachypnea. Spirometry shows reversible airflow obstruction (FEV1 improvement ≥12% after bronchodilator). In children ≥5 years, consider bronchial challenge testing if spirometry is normal. Elevated fractional exhaled nitric oxide (FeNO) may indicate eosinophilic airway inflammation.

4. Cystic Fibrosis

Cystic Fibrosis

Clinical History: Chronic cough with thick, sticky mucus production from early infancy. Recurrent respiratory infections, including pneumonia and sinusitis. Failure to thrive, malabsorption with steatorrhea, and salty-tasting skin. Family history of CF or carrier status. Infertility in males (absence of vas deferens) and reduced fertility in females.

Diagnostic Findings: Positive newborn screening test (elevated immunoreactive trypsinogen). Sweat chloride test ≥60 mmol/L confirms diagnosis. Genetic testing showing two disease-causing mutations in CFTR gene. Chest X-ray may show hyperinflation, bronchial wall thickening, and later bronchiectasis. Spirometry demonstrates obstructive pattern with reduced FEV1 and FVC. Sputum cultures often positive for Pseudomonas aeruginosa or Staphylococcus aureus.

5. Pertussis (Whooping Cough)

Pertussis (Whooping Cough)

Clinical History: Initial catarrhal stage with mild cough and rhinorrhea for 1-2 weeks. Progresses to paroxysmal stage with severe coughing fits, often followed by characteristic inspiratory "whoop" and/or post-tussive vomiting. Cough persists for weeks to months. More severe in young infants, often with apnea and cyanosis. Incomplete vaccination history or waning immunity in adolescents/adults.

Diagnostic Findings: Leukocytosis with lymphocytosis, especially in infants. PCR of nasopharyngeal swab positive for Bordetella pertussis. Culture on special media (e.g., Regan-Lowe) may be positive early in illness. Chest X-ray can show perihilar infiltrates or atelectasis. In classic cases, observation of paroxysmal cough with inspiratory whoop is diagnostic.

6. Respiratory Syncytial Virus (RSV) Infection

Respiratory Syncytial Virus (RSV) Infection

Clinical History: Most common in infants and young children, especially <2 years. Starts with upper respiratory symptoms (rhinorrhea, cough) progressing to lower respiratory involvement. Fever may be present. Increased work of breathing, poor feeding, and irritability in infants. Seasonal occurrence with peak in winter months. Higher risk in premature infants, those with chronic lung disease, or congenital heart disease.

Diagnostic Findings: Tachypnea, nasal flaring, chest retractions. Auscultation reveals wheezing and/or crackles. Hypoxemia on pulse oximetry. Rapid antigen detection tests or PCR of nasopharyngeal secretions positive for RSV. Chest X-ray may show hyperinflation, patchy infiltrates, or atelectasis.

7. Foreign Body Aspiration

Foreign Body Aspiration

Clinical History: Sudden onset of cough, choking, or respiratory distress, often while eating or playing with small objects. Common in children 6 months to 4 years. May have a clear episode of aspiration witnessed by caregiver, or present with persistent cough or recurrent pneumonia in same location. Types of aspirated objects vary by age and cultural practices.

Diagnostic Findings: Unilateral decreased breath sounds, wheezing, or stridor. Chest X-ray may show unilateral hyperinflation, atelectasis, or radio-opaque foreign body. Decubitus films can demonstrate air trapping. Bronchoscopy is both diagnostic and therapeutic, allowing visualization and removal of the foreign body.

8. Bronchopulmonary Dysplasia (BPD)

Bronchopulmonary Dysplasia (BPD)

Clinical History: Occurs in premature infants, especially those born at <32 weeks gestation or with birth weight <1500g. History of mechanical ventilation and oxygen therapy in neonatal period. Persistent oxygen requirement beyond 36 weeks postmenstrual age. Increased respiratory rate and work of breathing. Frequent respiratory infections and poor growth.

Diagnostic Findings: Tachypnea, retractions, and crackles on auscultation. Chest X-ray shows hyperinflation, areas of atelectasis, and cystic changes. Echocardiogram may show pulmonary hypertension. Oxygen requirement to maintain SpO2 >90%. Abnormal pulmonary function tests with decreased FEV1 and increased residual volume.

9. Primary Ciliary Dyskinesia (PCD)

Primary Ciliary Dyskinesia (PCD)

Clinical History: Chronic wet cough from early infancy. Recurrent otitis media and sinusitis. Neonatal respiratory distress in full-term infants. Recurrent pneumonia. Bronchiectasis developing in childhood or early adulthood. Male infertility. Approximately 50% have situs inversus (Kartagener syndrome).

Diagnostic Findings: Low nasal nitric oxide levels (<77 nL/min). Abnormal ciliary beat frequency and pattern on high-speed video microscopy. Electron microscopy of ciliary ultrastructure showing defects. Genetic testing revealing biallelic mutations in PCD-associated genes. Chest CT showing bronchiectasis, often in middle and lower lobes.

10. Vocal Cord Dysfunction (VCD)

Vocal Cord Dysfunction (VCD)

Clinical History: Episodes of dyspnea, throat tightness, and/or stridor, often misdiagnosed as asthma. Symptoms typically worse on inspiration. May be triggered by exercise, strong odors, or stress. More common in adolescents, particularly females. Often coexists with asthma but poorly responsive to standard asthma treatments.

Diagnostic Findings: Inspiratory stridor heard over the larynx during attacks. Flattening of inspiratory loop on flow-volume curves. Direct visualization of paradoxical vocal cord movement (adduction during inspiration) on laryngoscopy during symptomatic episodes. Normal pulmonary function tests between episodes. Methacholine challenge test may be negative, distinguishing from asthma.

11. Bronchiectasis (Non-Cystic Fibrosis)

Bronchiectasis (Non-Cystic Fibrosis)

Clinical History: Chronic productive cough with purulent sputum. Recurrent respiratory infections. Hemoptysis may occur. History of severe pneumonia, pertussis, or tuberculosis. Associated with immunodeficiencies, primary ciliary dyskinesia, or aspiration syndromes. Gradual onset of symptoms, often with delayed diagnosis.

Diagnostic Findings: Coarse crackles on auscultation, often localized. Digital clubbing in advanced cases. Chest CT shows bronchial dilation, bronchial wall thickening, and lack of bronchial tapering. Sputum culture often positive for Haemophilus influenzae, Pseudomonas aeruginosa, or other pathogens. Pulmonary function tests may show obstructive pattern.

12. Allergic Rhinitis

Allergic Rhinitis

Clinical History: Nasal congestion, clear rhinorrhea, sneezing, and itching of nose, eyes, and palate. Symptoms may be seasonal (e.g., pollen-related) or perennial (e.g., dust mites, pets). Often associated with allergic conjunctivitis. Family history of atopy common. May exacerbate asthma symptoms. Sleep disturbance and decreased quality of life in severe cases.

Diagnostic Findings: Pale, boggy nasal mucosa on anterior rhinoscopy. Transverse nasal crease in children who frequently rub their nose ("allergic salute"). Conjunctival injection and eyelid swelling may be present. Positive skin prick tests or serum-specific IgE to relevant allergens. Elevated total serum IgE. Nasal smear showing eosinophilia.

13. Obstructive Sleep Apnea (OSA)

Obstructive Sleep Apnea (OSA)

Clinical History: Snoring, observed apneas, gasping or choking during sleep. Restless sleep, enuresis, morning headaches, daytime sleepiness (more common in adolescents), or behavioral problems. Risk factors include obesity, craniofacial abnormalities, and neuromuscular disorders. Failure to thrive may occur in severe cases.

Diagnostic Findings: Adenotonsillar hypertrophy on oropharyngeal examination. Polysomnography shows recurrent episodes of complete or partial upper airway obstruction with oxygen desaturation and/or arousal. Apnea-Hypopnea Index (AHI) ≥1 event/hour in children. Elevated end-tidal or transcutaneous CO2. Systemic hypertension may be present in severe cases.

14. Acute Epiglottitis

Acute Epiglottitis

Clinical History: Rapid onset of high fever, sore throat, and progressive respiratory distress. Difficulty swallowing with drooling. Child often prefers to sit leaning forward with neck extended (tripod position). Less common since Hib vaccine but still occurs. Can affect any age but more severe in young children.

Diagnostic Findings: Toxic appearance, stridor, and respiratory distress. Muffled voice ("hot potato" voice). Reluctance to speak or swallow. Lateral neck X-ray shows thickened epiglottis ("thumb sign"). Direct visualization of cherry-red, swollen epiglottis on careful laryngoscopy in controlled setting. Blood cultures may be positive for causative organism (often Haemophilus influenzae type b in unvaccinated children).

15. Croup (Laryngotracheobronchitis)

Clinical History: Typically affects children 6 months to 3 years. Begins with coryzal symptoms, progressing to barking cough, hoarseness, and inspiratory stridor. Symptoms often worsen at night. Usually self-limiting but can be recurrent. More common in fall and winter months. Viral etiology, most commonly parainfluenza virus.

Diagnostic Findings: Inspiratory stridor, barking cough. Mild tachypnea and retractions in more severe cases. "Steeple sign" on anteroposterior neck X-ray (narrowing of the subglottic airway). Westley Croup Score used to assess severity. Pulse oximetry may show hypoxemia in severe cases. Viral studies may identify causative agent.

16. Tracheomalacia

Clinical History: Noisy breathing (stridor or wheeze), barking cough, recurrent respiratory infections. Symptoms worsen with crying, feeding, or upper respiratory infections. May have history of prolonged intubation or tracheostomy. Can be primary (congenital) or secondary (acquired).

Diagnostic Findings: Expiratory stridor or wheeze that worsens with agitation or feeding. Dynamic airway collapse seen on bronchoscopy or dynamic CT. Pulmonary function tests may show reduced peak expiratory flow. Fluoroscopy may demonstrate excessive airway collapse during expiration.

17. Bronchiolitis Obliterans

Clinical History: Persistent wheezing, cough, and dyspnea following severe lower respiratory tract infection (often adenovirus) or in post-transplant patients. Gradual onset over weeks to months. Poor response to bronchodilators. History of stem cell or lung transplantation increases risk.

Diagnostic Findings: Obstructive pattern on pulmonary function tests with reduced FEV1 and FEF25-75%. Chest CT shows mosaic attenuation, air trapping, and bronchial wall thickening. Lung biopsy may show constrictive bronchiolitis. Normal or near-normal total lung capacity distinguishes from restrictive diseases.

18. Alpha-1 Antitrypsin Deficiency

Clinical History: Early-onset emphysema, particularly in lower lobes. Chronic cough and dyspnea, often misdiagnosed as asthma. Liver disease may be present (elevated liver enzymes, hepatomegaly). Family history of early emphysema or liver disease. More severe in smokers.

Diagnostic Findings: Low serum alpha-1 antitrypsin levels (<11 μmol/L). Genetic testing shows homozygous PiZZ genotype or other severe deficiency state. Chest CT demonstrates panlobular emphysema, predominantly in lower lobes. Pulmonary function tests show obstructive pattern with reduced DLCO.

19. Pulmonary Embolism

Clinical History: Sudden onset of dyspnea, pleuritic chest pain, and/or hemoptysis. Risk factors include recent surgery, immobilization, oral contraceptive use, obesity, and inherited thrombophilias. Less common in children than adults but can occur, especially in adolescents.

Diagnostic Findings: Tachypnea, tachycardia, hypoxemia. ECG may show sinus tachycardia, right heart strain (S1Q3T3 pattern). Elevated D-dimer (high sensitivity, low specificity). CT pulmonary angiography shows filling defects in pulmonary arteries. V/Q scan may be used if CT contraindicated. Echocardiography may show right ventricular strain in larger emboli.

20. Pulmonary Hypertension

Clinical History: Progressive dyspnea on exertion, fatigue, chest pain, and syncope. In infants, may present with failure to thrive. Various etiologies including idiopathic, congenital heart disease, chronic lung disease, and connective tissue disorders. Family history may be present in heritable forms.

Diagnostic Findings: Loud P2 on cardiac auscultation, right ventricular heave. ECG shows right axis deviation and right ventricular hypertrophy. Echocardiography demonstrates elevated right ventricular systolic pressure and right ventricular hypertrophy. Cardiac catheterization confirms elevated mean pulmonary artery pressure ≥25 mmHg at rest. 6-minute walk test shows decreased exercise capacity.

21. Bronchopulmonary Sequestration

Clinical History: May be asymptomatic or present with recurrent pneumonia in the same location. Hemoptysis can occur. Intralobar type more common than extralobar. May be detected prenatally on routine ultrasound. Can be associated with other congenital anomalies.

Diagnostic Findings: Chest CT shows a mass of lung tissue with its own systemic arterial supply, usually from the aorta. Angiography can delineate the aberrant blood supply. Bronchoscopy typically normal. Surgical resection is both diagnostic and therapeutic.

22. Congenital Diaphragmatic Hernia (CDH)

Clinical History: Often diagnosed prenatally or presents with respiratory distress shortly after birth. Left-sided defects more common than right-sided. Associated pulmonary hypoplasia and pulmonary hypertension. May have scaphoid abdomen and shifted heart sounds to right side in left CDH.

Diagnostic Findings: Prenatal ultrasound or MRI shows abdominal organs in chest cavity. Postnatal chest X-ray demonstrates bowel loops in thorax with mediastinal shift. Echocardiography to assess for pulmonary hypertension. CT or MRI can provide detailed anatomy for surgical planning.

23. Bronchogenic Cyst

Clinical History: Often asymptomatic and discovered incidentally. May cause compression symptoms such as cough, dyspnea, or recurrent infections. Can enlarge over time. Rarely, may become infected or rupture.

Diagnostic Findings: Chest CT shows a well-circumscribed, homogeneous, fluid-filled lesion, typically in the mediastinum or lung parenchyma. MRI can help differentiate from other cystic lesions. If large, may cause tracheal or bronchial compression visible on bronchoscopy.

24. Pneumothorax

Clinical History: Sudden onset of chest pain and dyspnea. May be spontaneous (more common in tall, thin adolescents) or secondary to trauma, asthma exacerbation, or mechanical ventilation. History of previous pneumothorax increases risk. Tension pneumothorax presents with rapid respiratory distress and hemodynamic compromise.

Diagnostic Findings: Decreased breath sounds and hyperresonance to percussion on affected side. Chest X-ray shows visible visceral pleural line and absence of lung markings peripheral to this line. CT can detect small pneumothoraces missed on X-ray. Tension pneumothorax shows mediastinal shift away from affected side.

25. Pulmonary Interstitial Glycogenosis (PIG)

Clinical History: Rare interstitial lung disease of infancy. Presents with tachypnea and hypoxemia in neonatal period or early infancy. Often associated with other developmental lung abnormalities. May have history of prematurity or be small for gestational age.

Diagnostic Findings: Chest CT shows diffuse ground-glass opacities and septal thickening. Lung biopsy demonstrates expanded interstitium with immature mesenchymal cells containing abundant glycogen (PAS-positive, diastase-sensitive). Genetic testing to rule out surfactant protein deficiencies.

26. Primary Pulmonary Lymphangiectasia

Clinical History: Congenital disorder presenting with severe respiratory distress at birth or in early infancy. Poor feeding, failure to thrive. Recurrent chylothorax may occur. High mortality in neonatal period, but some cases have more indolent course.

Diagnostic Findings: Chest X-ray shows bilateral interstitial infiltrates. CT demonstrates diffuse thickening of interlobular septa and patchy ground-glass opacities. Lymphangiography may show abnormal pulmonary lymphatics. Lung biopsy shows dilated lymphatic channels in pleura, interlobular septa, and peribronchial areas.

27. Plastic Bronchitis

Clinical History: Recurrent episodes of dyspnea and cough productive of branching bronchial casts. Often associated with congenital heart disease (especially after Fontan procedure), asthma, or cystic fibrosis. Can cause life-threatening airway obstruction.

Diagnostic Findings: Chest X-ray may show atelectasis or infiltrates. Bronchoscopy reveals bronchial casts, which can be removed for diagnosis and treatment. Histology of casts varies depending on etiology (inflammatory vs. lymphatic). Lymphatic imaging (e.g., dynamic contrast MR lymphangiography) may show abnormal pulmonary lymphatic flow in cardiac cases.

28. Pulmonary Alveolar Proteinosis (PAP)

Clinical History: Gradual onset of dyspnea and cough. Can occur at any age but rare in children. May be primary (autoimmune or genetic) or secondary to various conditions. Often indolent course with periods of spontaneous improvement and worsening.

Diagnostic Findings: Chest CT shows crazy-paving pattern (ground-glass opacities with superimposed septal thickening). Bronchoalveolar lavage yields milky fluid with PAS-positive material. Elevated serum GM-CSF autoantibodies in autoimmune PAP. Genetic testing for SFTPB, SFTPC, or ABCA3 mutations in congenital cases.

29. Laryngomalacia

Clinical History: Most common cause of stridor in infants. Inspiratory stridor worse when supine, feeding, or agitated. Usually presents within first few weeks of life. Often resolves spontaneously by 18-24 months. Severe cases may have feeding difficulties, failure to thrive, or obstructive sleep apnea.

Diagnostic Findings: Flexible laryngoscopy shows omega-shaped or tubular epiglottis, short aryepiglottic folds, and prolapse of supraarytenoid tissue during inspiration. Polysomnography may be needed to assess for obstructive sleep apnea in severe cases. Airway fluoroscopy can demonstrate dynamic airway collapse.

30. Pulmonary Langerhans Cell Histiocytosis (PLCH)

Clinical History: Rare in children, more common in adolescents and young adults. Nonproductive cough, dyspnea, chest pain, and constitutional symptoms. Strong association with cigarette smoking in adults. May be part of multisystem LCH in children.

Diagnostic Findings: Chest CT shows cystic and nodular lesions predominantly in upper and middle lung zones, sparing costophrenic angles. Lung biopsy shows Langerhans cell infiltrates (CD1a and S100 positive). Pulmonary function tests may show restrictive, obstructive, or mixed pattern with reduced DLCO.

31. Pulmonary Arteriovenous Malformation (PAVM)

Clinical History: May be asymptomatic or present with dyspnea, hemoptysis, or neurological symptoms from paradoxical embolism. Often associated with hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome). Increased risk of brain abscess and stroke.

Diagnostic Findings: Chest CT with contrast shows direct communication between pulmonary artery and vein. Contrast echocardiography demonstrates right-to-left shunt. Pulmonary angiography is gold standard for diagnosis and can guide treatment. Genetic testing for ENG, ACVRL1, or SMAD4 mutations in suspected hereditary hemorrhagic telangiectasia.

32. Congenital Lobar Emphysema

Clinical History: Usually presents in neonatal period or early infancy with progressive respiratory distress. Left upper lobe most commonly affected, followed by right middle lobe. May be asymptomatic and discovered incidentally on chest imaging.

Diagnostic Findings: Chest X-ray shows hyperinflation of affected lobe with mediastinal shift away from affected side. CT confirms lobar hyperinflation and can identify any extrinsic compression or intrinsic obstruction. Ventilation-perfusion scan shows decreased perfusion to affected lobe.

33. Primary Ciliary Dyskinesia (PCD)

34. Respiratory Distress Syndrome (RDS)

Clinical History: Primarily affects premature infants, especially those born at <34 weeks gestation. Presents shortly after birth with tachypnea, grunting, nasal flaring, and intercostal retractions. Risk increases with decreasing gestational age. Maternal diabetes and male sex are additional risk factors.

Diagnostic Findings: Chest X-ray shows diffuse ground-glass opacities with air bronchograms and decreased lung volumes. Blood gases reveal hypoxemia and may show respiratory acidosis. Surfactant protein B and C levels may be decreased in tracheal aspirates. Lung ultrasound demonstrates diffuse B-lines and pleural line abnormalities.

35. Meconium Aspiration Syndrome

Clinical History: Occurs in term or post-term infants with history of meconium-stained amniotic fluid. Presents with respiratory distress immediately after birth. May have history of fetal distress or low Apgar scores. Risk factors include maternal hypertension, diabetes, and post-term delivery.

Diagnostic Findings: Chest X-ray shows patchy infiltrates, areas of hyperinflation, and possible pneumothorax. Presence of meconium below the vocal cords on direct laryngoscopy. Blood gases may show hypoxemia and respiratory acidosis. Persistent pulmonary hypertension may complicate severe cases, detectable on echocardiography.

36. Transient Tachypnea of the Newborn (TTN)

Clinical History: Typically affects term or late preterm infants. Presents within hours of birth with tachypnea, mild respiratory distress. Often follows cesarean section or precipitous delivery. Usually self-resolves within 24-72 hours. More common in males and infants of diabetic mothers.

Diagnostic Findings: Chest X-ray shows fluid in fissures, perihilar streaking, and sometimes mild cardiomegaly. Lung ultrasound demonstrates a "double lung point" sign. Blood gases usually show mild hypoxemia without significant CO2 retention. Symptoms improve rapidly with minimal intervention.

37. Bronchopulmonary Dysplasia (BPD)

Clinical History: Develops in premature infants, especially those born at <32 weeks gestation. History of mechanical ventilation and oxygen therapy in neonatal period. Persistent oxygen requirement beyond 36 weeks postmenstrual age. Increased respiratory rate and work of breathing. Frequent respiratory infections and poor growth.

Diagnostic Findings: Chest X-ray shows hyperinflation, areas of atelectasis, and cystic changes. Echocardiogram may show pulmonary hypertension. Oxygen requirement to maintain SpO2 >90%. Abnormal pulmonary function tests with decreased FEV1 and increased residual volume. Graded based on oxygen requirement at 36 weeks postmenstrual age or 56 days of life, whichever comes first.

38. Congenital Pulmonary Airway Malformation (CPAM)

Clinical History: Often diagnosed prenatally on ultrasound. May be asymptomatic at birth or present with respiratory distress. Risk of recurrent pneumonia if undiagnosed. Malignant transformation possible in some types. Can be associated with other congenital anomalies.

Diagnostic Findings: Prenatal ultrasound or MRI shows cystic or solid lung lesion. Postnatal CT confirms diagnosis and defines anatomy. Classified into 5 types based on histological features. May require surgical resection for definitive diagnosis and treatment.

39. Pulmonary Hypoplasia

Clinical History: Can be primary or secondary to conditions limiting fetal lung growth (e.g., oligohydramnios, congenital diaphragmatic hernia). Presents with severe respiratory distress at birth. Often associated with other congenital anomalies.

Diagnostic Findings: Chest X-ray shows small lung fields and elevated hemidiaphragms. CT demonstrates decreased lung volume and reduced number of airways. Pulmonary function tests show severely reduced lung volumes. Histologically, reduced number of airway generations and alveoli.

40. Acute Chest Syndrome in Sickle Cell Disease

Clinical History: Acute onset of chest pain, fever, tachypnea, and hypoxemia in patient with sickle cell disease. Often triggered by infection, fat embolism, or hypoventilation. Can rapidly progress to acute respiratory failure. Recurrent episodes can lead to chronic lung disease.

Diagnostic Findings: Chest X-ray shows new pulmonary infiltrate involving at least one complete lung segment. Blood tests reveal decreased hemoglobin from baseline. Blood cultures may be positive if infectious etiology. Elevated LDH and sometimes bilirubin. Arterial blood gas may show hypoxemia and new oxygen requirement.

41. Aspiration Pneumonia

Clinical History: Often occurs in children with neurological impairment, gastroesophageal reflux, or swallowing dysfunction. Can be acute (single large aspiration) or chronic (recurrent small aspirations). Symptoms include cough, fever, and respiratory distress. May have history of choking or coughing while feeding.

Diagnostic Findings: Chest X-ray typically shows infiltrates in dependent lung segments (e.g., posterior segments of upper lobes and superior segments of lower lobes when upright). Bronchoscopy may reveal lipid-laden macrophages in BAL fluid. Videofluoroscopic swallow study can demonstrate aspiration during feeding.

42. Pneumocystis jirovecii Pneumonia (PCP)

Clinical History: Occurs in immunocompromised children, particularly those with HIV/AIDS, primary immunodeficiencies, or on immunosuppressive therapy. Presents with progressive dyspnea, nonproductive cough, and fever. Onset can be subacute in HIV-infected children not on prophylaxis.

Diagnostic Findings: Chest X-ray shows bilateral interstitial infiltrates progressing to alveolar infiltrates. High-resolution CT demonstrates ground-glass opacities with upper lobe predominance. Elevated serum LDH. Diagnosis confirmed by identification of P. jirovecii cysts or trophozoites in induced sputum or BAL fluid, often using immunofluorescence techniques.

43. Pulmonary Hemorrhage Syndrome in Infants

Clinical History: Acute onset of respiratory distress, often with hemoptysis or blood-tinged tracheal secretions. Can occur in previously healthy infants or those with underlying conditions. Risk factors include prematurity, coagulation disorders, and cardiovascular disease.

Diagnostic Findings: Chest X-ray shows diffuse, bilateral alveolar infiltrates. Rapid drop in hemoglobin. Bloody return on endotracheal suctioning. BAL demonstrates hemosiderin-laden macrophages. Coagulation studies to rule out bleeding diathesis. Echocardiography to assess for cardiac causes.

44. Congenital Tuberculosis

Clinical History: Rare condition, usually presenting in first few weeks of life. Nonspecific symptoms including fever, poor feeding, failure to thrive, and respiratory distress. Hepatosplenomegaly common. Maternal history of tuberculosis or HIV infection is a key risk factor.

Diagnostic Findings: Chest X-ray may show miliary pattern or focal infiltrates. Liver biopsy often diagnostic, showing caseating granulomas. Tuberculin skin test usually negative in neonatal period. Gastric aspirates or tracheal aspirates positive for acid-fast bacilli on smear or culture. PCR for Mycobacterium tuberculosis on various specimens can provide rapid diagnosis.

45. Pulmonary Edema

Clinical History: Can be cardiogenic (due to heart failure) or non-cardiogenic (e.g., ARDS, neurogenic). Presents with progressive dyspnea, orthopnea, and sometimes frothy sputum. In cardiogenic edema, may have history of congenital heart disease or cardiomyopathy.

Diagnostic Findings: Chest X-ray shows pulmonary vascular congestion, interstitial edema, and sometimes alveolar edema with bat-wing distribution in severe cases. Echocardiography helps differentiate cardiogenic from non-cardiogenic causes. Elevated BNP or NT-proBNP supports cardiogenic etiology. Lung ultrasound demonstrates B-lines.

46. Pulmonary Contusion

Clinical History: Results from blunt chest trauma. Presents with dyspnea, tachypnea, and sometimes hemoptysis. Pain may limit respiratory effort. Can progress over 24-48 hours. Risk of secondary pneumonia or ARDS in severe cases.

Diagnostic Findings: Chest X-ray shows patchy alveolar infiltrates, often not visible immediately after injury. CT more sensitive, demonstrating focal areas of increased lung attenuation. Blood gases may reveal hypoxemia. Bronchoscopy may show mucosal bleeding if performed.

47. Bronchiolitis Obliterans Organizing Pneumonia (BOOP)

Clinical History: Rare in children. Presents with cough, dyspnea, and sometimes fever. Can be idiopathic or associated with connective tissue diseases, infections, or drug reactions. Often subacute onset over weeks to months.

Diagnostic Findings: Chest X-ray shows bilateral patchy alveolar opacities. CT demonstrates characteristic peripheral consolidations and ground-glass opacities with air bronchograms. Pulmonary function tests show restrictive pattern. Lung biopsy reveals characteristic intraluminal buds of granulation tissue in distal airways and alveolar ducts.

48. Pulmonary Lymphangiomatosis

Clinical History: Rare disorder characterized by diffuse proliferation of lymphatic channels in lungs and sometimes other organs. Can present at any age but often in childhood. Symptoms include dyspnea, cough, and recurrent chylothorax. May have associated skeletal involvement.

Diagnostic Findings: Chest CT shows diffuse interstitial thickening, patchy ground-glass opacities, and sometimes cystic changes. Characteristic involvement of mediastinum and pleura. MRI useful for evaluating extent of disease. Lung biopsy shows proliferation of thin-walled lymphatic channels in bronchovascular bundles and interlobular septa.

49. Pulmonary Manifestations of Systemic Lupus Erythematosus (SLE)

Clinical History: Can affect lungs in various ways including pleuritis, acute lupus pneumonitis, diffuse alveolar hemorrhage, and chronic interstitial lung disease. Presents with dyspnea, pleuritic chest pain, cough, and sometimes hemoptysis. Often accompanied by extra-pulmonary manifestations of SLE.

Diagnostic Findings: Chest X-ray findings vary depending on specific manifestation. Pleural effusions common. High-resolution CT may show ground-glass opacities, consolidation, or interstitial changes. Pulmonary function tests often show restrictive pattern. Elevated anti-dsDNA antibodies and low complement levels support active SLE. Lung biopsy may be needed in some cases.

50. High Altitude Pulmonary Edema (HAPE)

Clinical History: Occurs in children and adults ascending to high altitudes (typically >2500m) without proper acclimatization. Presents with dyspnea, cough, and sometimes pink frothy sputum. Often accompanied by symptoms of acute mountain sickness (headache, nausea). Previous episodes increase risk.

Diagnostic Findings: Chest X-ray shows patchy alveolar infiltrates, often with right middle lobe predominance. Hypoxemia on pulse oximetry or arterial blood gas. Elevated pulmonary artery pressure on echocardiography. Lung ultrasound demonstrates multiple B-lines. Clinical improvement with descent to lower altitude or oxygen therapy is diagnostic.