Differential Diagnosis of Asthma: Adults and Pediatrics

Summary Tables

Differential Diagnosis in Adults

Condition	Key Differences	Diagnostic Tests
COPD	History of smoking, chronic cough, sputum	Spirometry, FEV1/FVC ratio <0.70 post-bronchodilator
Heart Failure	Fluid overload symptoms, cardiac history	Echocardiogram, BNP/NT-proBNP, chest X-ray
Vocal Cord Dysfunction (VCD)	Inspiratory stridor, voice changes	Laryngoscopy, spirometry
Pulmonary Embolism (PE)	Acute pleuritic chest pain, hemoptysis	D-dimer, CT pulmonary angiography
Bronchiectasis	Chronic productive cough, recurrent infections	High-resolution CT scan
GERD	Heartburn, regurgitation	Esophageal pH monitoring, endoscopy
Upper Airway Cough Syndrome	Postnasal drip, throat clearing	Sinus CT, allergy testing

Differential Diagnosis in Pediatrics (Ages 6 months - 14 years old)

Condition	Key Differences	Diagnostic Tests
Viral Bronchiolitis	Wheezing, viral infection	Nasopharyngeal swab, clinical presentation
Croup	Barking cough, inspiratory stridor	Clinical diagnosis, neck X-ray
Foreign Body Aspiration	Sudden distress, localized wheezing	Chest X-ray, bronchoscopy
Cystic Fibrosis (CF)	Chronic cough, failure to thrive	Sweat chloride test, genetic testing
Congenital Heart Disease	Poor feeding, cyanosis, murmur	Echocardiogram, chest X-ray, ECG
Primary Ciliary Dyskinesia	Chronic cough, recurrent infections	Nasal nitric oxide, ciliary biopsy
GERD	Regurgitation, failure to thrive	pH probe study, esophageal manometry

This detailed approach should provide a comprehensive guide for residents in both internal medicine and pediatrics, ensuring accurate differential diagnosis and effective management of asthma in different patient populations.

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Asthma can present with symptoms that overlap with many other conditions, making differential diagnosis crucial. Here is a detailed approach to differentiating asthma from other conditions in both adults and pediatric patients, tailored for residents in internal medicine and pediatrics.

Differential Diagnosis in Adults

1. Chronic Obstructive Pulmonary Disease (COPD)

   • Key Differences: COPD is typically seen in older adults with a history of smoking. Symptoms include chronic cough, sputum production, and progressive dyspnea.

   • Diagnostic Tests: Spirometry showing irreversible airflow limitation; FEV1/FVC ratio <0.70 post-bronchodilator.

2. Heart Failure

   • Key Differences: Presents with symptoms of fluid overload such as peripheral edema, orthopnea, and paroxysmal nocturnal dyspnea. A history of cardiac disease is often present.

   • Diagnostic Tests: Echocardiogram, BNP/NT-proBNP levels, chest X-ray showing cardiomegaly and pulmonary edema.

3. Vocal Cord Dysfunction (VCD)

   • Key Differences: Inspiratory stridor, voice changes, and symptoms triggered by stress. Symptoms do not improve with asthma medications.

   • Diagnostic Tests: Laryngoscopy during symptoms, spirometry may show a normal expiratory flow-volume loop with flattening of the inspiratory loop.

4. Pulmonary Embolism (PE)

   • Key Differences: Acute onset of pleuritic chest pain, hemoptysis, and dyspnea. Risk factors include recent surgery, immobilization, and history of thromboembolism.

   • Diagnostic Tests: D-dimer, CT pulmonary angiography, V/Q scan.

5. Bronchiectasis

   • Key Differences: Chronic productive cough with large volumes of sputum, recurrent respiratory infections. Often associated with underlying conditions like cystic fibrosis.

   • Diagnostic Tests: High-resolution CT scan showing bronchial dilation and wall thickening.

6. Gastroesophageal Reflux Disease (GERD)

   • Key Differences: Symptoms include heartburn, regurgitation, and chronic cough. Asthma symptoms may worsen postprandially or at night.

   • Diagnostic Tests: Esophageal pH monitoring, endoscopy.

7. Upper Airway Cough Syndrome (UACS)

   • Key Differences: Chronic cough with postnasal drip, throat clearing, and rhinitis symptoms. Often associated with allergies or sinusitis.

   • Diagnostic Tests: Sinus CT scan, allergy testing, clinical response to antihistamines and nasal corticosteroids.
     

Differential Diagnosis in Pediatrics (Ages 6 months - 14 years)

1. Viral Bronchiolitis

   • Key Differences: Common in infants and young children. Symptoms include wheezing, cough, and difficulty breathing typically associated with a viral infection.

   • Diagnostic Tests: Nasopharyngeal swab for respiratory syncytial virus (RSV) and other viruses, clinical presentation.

2. Croup (Laryngotracheobronchitis)

   • Key Differences: Barking cough, inspiratory stridor, and hoarseness. Symptoms worsen at night and may follow an upper respiratory infection.

   • Diagnostic Tests: Clinical diagnosis, neck X-ray may show “steeple sign” indicating subglottic narrowing.

3. Foreign Body Aspiration

   • Key Differences: Sudden onset of respiratory distress, coughing, and localized wheezing or decreased breath sounds. Often occurs in toddlers.

   • Diagnostic Tests: Chest X-ray, bronchoscopy for definitive diagnosis and removal.

4. Cystic Fibrosis (CF)

   • Key Differences: Chronic cough, failure to thrive, greasy stools, and recurrent lung infections. Family history may be positive for CF.

   • Diagnostic Tests: Sweat chloride test, genetic testing for CFTR mutations.

5. Congenital Heart Disease

   • Key Differences: Symptoms of heart failure such as poor feeding, failure to thrive, cyanosis, and murmur.

   • Diagnostic Tests: Echocardiogram, chest X-ray, ECG.

6. Primary Ciliary Dyskinesia

   • Key Differences: Chronic cough, recurrent sinus and ear infections, situs inversus in some cases.

   • Diagnostic Tests: Nasal nitric oxide measurement, electron microscopy of ciliary biopsy.

7. Gastroesophageal Reflux Disease (GERD)

   • Key Differences: Recurrent regurgitation, failure to thrive, and chronic cough. Symptoms may worsen when lying down or post feeding.

   • Diagnostic Tests: pH probe study, esophageal manometry.