Differentials
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Astma bij volwassenen: diagnose en monitoring in de eerste lijnPublished by: Werkgroep Ontwikkeling Richtlijnen Eerste Lijn (Worel)Last published: 2020Asthme chez l’adulte : diagnostic et surveillance en soins de santé primairesPublished by: Groupe de Travail Développement de recommmandations de première ligneLast published: 2020Cystic fibrosis
SIGNS / SYMPTOMS
Chronic, sometimes productive cough with a possible family history of cystic fibrosis.
Nasal polyposis at or before 12 years of age and symptoms related to other organ involvement, such as diarrhea, malabsorption, or failure to thrive.
INVESTIGATIONS
Sweat chloride testing: level of sweat chloride ≥60 mEq/L.
Consider repeat testing.
Chronic rhinosinusitis
SIGNS / SYMPTOMS
May present with nocturnal cough and dyspnea from postnasal discharge.
May coexist with asthma.
INVESTIGATIONS
Anterior rhinoscopy or nasal endoscopy may show inflammation, purulent discharge, edema, or frank polyps.
CT may show opacification of involved sinuses, mucosal thickening, air-fluid levels, or anatomic abnormalities such as polyps.
Tracheomalacia
SIGNS / SYMPTOMS
Symptoms are usually positionally dependent.
Expiratory stridor and a barking brassy cough, wheezing, and possibly additional breath sound at the end of expiration (the bagpipe sign) are common. Less common findings are inspiratory stridor, episodes of holding of breath, anoxia, recurrent respiratory infections, retraction of intercostal and subcostal muscles, failure to thrive, and respiratory and cardiac arrest.[69]
INVESTIGATIONS
Dynamic CT using volumetric analysis may be helpful in the initial diagnosis of tracheomalacia, with reported accuracy rates as high as 97%.[70] Confirmatory testing with bronchoscopy may be performed as indicated, which remains the gold standard for diagnosis. For diagnosis, bronchoscopy must demonstrate ≥50% decrease in airway lumen size on forced expiration.
Vascular ring
SIGNS / SYMPTOMS
Wheezing, shortness of breath, occasional stridor.
INVESTIGATIONS
CT chest with contrast: double aortic arch, abnormal take-off of the innominate artery, anomaly of left pulmonary artery, right aortic arch, aberrant right subclavian, enlarged pulmonary veins.[69]
Foreign body aspiration
SIGNS / SYMPTOMS
Wheezing, shortness of breath, occasional stridor are common.
If the foreign body is in the peripheral airway, localized one-sided wheezing or collapse of the distal lung tissue is found.
INVESTIGATIONS
CXR, CT chest, or bronchoscopy shows the foreign body.
Recurrent retrograde aspiration
SIGNS / SYMPTOMS
Gastroesophageal reflux disease (GERD) may lead to aspiration. GERD is a clinical diagnosis that presents with heartburn and regurgitation. Prevalent in patients with poorly controlled asthma.[46]
The link between GERD and the development of asthma remains unclear, but could be related to chronic irritation and inflammation of the airways following exposure to gastric contents.[47][48]
Treating symptomatic GERD can moderately improve lung function and use of rescue medication in patients with moderate-to-severe asthma.[49]
INVESTIGATIONS
Symptomatic improvement after treating GERD; focal signs of pneumonitis or pneumonia on chest radiography.
Vocal cord dysfunction
SIGNS / SYMPTOMS
Inspiratory and expiratory wheezing is often difficult to differentiate.
Should be considered in steroid-resistant asthma patients, but is often coexistent with asthma.
INVESTIGATIONS
Direct visualization of the vocal cords with rhinolaryngoscopy during a spell. Inspiratory flow volume loop is helpful when abnormal (flattened).
Alpha-1 antitrypsin deficiency
SIGNS / SYMPTOMS
Wheezing, resistant to management.
May have a family history of parents or grandparents dying of lung disease.
Often early diagnosis of COPD (e.g., under 40 years) or severity of radiographic disease out of proportion to smoking history.
INVESTIGATIONS
Testing for the alpha-1 antitrypsin phenotype.
COPD
SIGNS / SYMPTOMS
History of smoking or long-standing asthma.
Dyspnea occurs with or without wheezing and coughing.
Examination may show barrel chest, hyper-resonance to percussion, and distant breath sounds.
INVESTIGATIONS
Pulmonary function tests (PFTs) with elevated residual volume (RV), total lung capacity (TLC), and a flow volume loop with bronchodilator showing an obstructive pattern with an increase in TLC and RV and a reduction in forced expiratory flow at one second (FEV₁), FEV₁/forced vital capacity (FVC) ratio <70%; total absence of reversibility is neither required nor the most typical result, but PFTs must not return to normal after administration of aerosolized bronchodilator.
CXR showing hyperinflation of the lungs.
Bronchiectasis
SIGNS / SYMPTOMS
Dyspnea, cough, and wheezing and, if severe, recurrent pulmonary infections.
INVESTIGATIONS
High-resolution CT chest: dilated airways, bronchial wall thickening.
Can occasionally be seen on CXR.
Pulmonary embolism
SIGNS / SYMPTOMS
Patients have a wide variety of presentations but most common is shortness of breath and pleuritic pain.
INVESTIGATIONS
Risk stratification with appropriate scoring systems and serum D-dimer measurements should be done.
Confirmation of pulmonary embolism can be done using CT pulmonary angiography. Alternative tests include the less sensitive ventilation-perfusion (V/Q) scan.
Congestive heart failure
SIGNS / SYMPTOMS
History of coronary artery disease or uncontrolled hypertension.
Exam shows dependent edema, elevated jugular venous pressure, and basal pulmonary crepitations.
INVESTIGATIONS
CXR may show increased alveolar markings, fluid in fissures, and pleural effusions.
Echocardiogram may show reduced or preserved left ventricular ejection fraction. Serum B-natriuretic peptide may be elevated.
Common variable immunodeficiency
SIGNS / SYMPTOMS
History of recurrent, usually sinopulmonary, infections.
INVESTIGATIONS
Serum IgG level <500 mg/dL. Generally presents with bronchiectasis on imaging.
Exercise-induced laryngeal obstruction
SIGNS / SYMPTOMS
In athletes, there should be a low threshold for ruling out exercise-induced laryngeal obstruction (EILO). Symptoms associated with EILO typically include noisy breathing and upper chest/throat discomfort or restriction, and are amplified during intense exercise.[54]
INVESTIGATIONS
Continuous laryngoscopy during exercise is the gold-standard test for assessing exercise-related laryngeal conditions.[54]
Breathing pattern disorder
SIGNS / SYMPTOMS
Breathing pattern disorder (BPD) is a common cause of unexplained dyspnea in athletes with variable symptoms and normal investigations.[54][71]
Breathlessness, light-headedness, and peripheral tingling are common.
BPD may be comorbid with exercise-induced laryngeal obstruction and exercise-induced bronchoconstriction. Hyperventilation syndrome is the most common BPD, but other forms may coexist or appear in isolation.
In athletes, there should be a low threshold for ruling out BPD.
INVESTIGATIONS
Cardiopulmonary exercise testing may be helpful in differentiating BPD.[54]
Pertussis
SIGNS / SYMPTOMS
History and exam reveal prolonged paroxysms of barking cough, sometimes with stridor.
These symptoms usually warrant further investigation.
INVESTIGATIONS
Diagnosis can usually be confirmed by culture of a nasopharyngeal aspirate or swab from the posterior nasopharynx (e.g., with or without nucleic acid amplification testing).
Serology and complete blood count testing can be useful.
Important to diagnose and treat early.
Tuberculosis
SIGNS / SYMPTOMS
Chronic cough, hemoptysis, dyspnea.
Fatigue, fever, (night) sweats, anorexia, weight loss.
These symptoms warrant further investigation.
INVESTIGATIONS
CXR is almost always abnormal, typically showing fibronodular opacities in upper lobes, with or without cavitation.
Other tests include sputum acid-fast bacilli smear, sputum culture, complete blood count, and nucleic acid amplification tests (on at least one respiratory specimen).
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