Differential diagnosis project
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Instructions
Differentiating Legionnaires' disease from other diseases
The following conditions must be considered in the differential diagnosis of Legionnaires' disease:
DDx [1][2][3][4][5][6][7]- Acute interstitial pneumonia
DDx - Mycoplasma pneumonia
DDx - Pneumococcal pneumonia
DDx - Pneumocystis carinii pneumonia
DDx - Pulmonary embolism
DDx - Streptococcal pneumonia
DDx - Viral pneumonia
DDx
Findings suggestive of Legionnaires' disease
Clinical manifestations
- High grade fever
- Dry cough
- Progressive dyspnea
- Bronchial breath sounds
- Adult respiratory distress syndrome
Laboratory abnormalities
- Legionella urinary antigen positive
- Alveolar consolidation on chest radiograph
- Lobar consolidation on chest radiograph
Findings suggestive of Acute interstitial pneumonia
Clinical manifestations
- Dry cough
- Progressive dyspnea
- Adult respiratory distress syndrome
Laboratory abnormalities
- Disseminated consolidation on chest radiograph
- Interstitial infiltrate on chest radiograph
- Increased uptake on Gallium scan
Findings suggestive of Mycoplasma pneumonia
Clinical manifestations
- Dry cough
- Pleuritic chest pain
- Inflammed, opaque, hypomobile tympanic membrane
- Bronchial breath sounds
Laboratory abnormalities
- Lymphocytosis
- Cold agglutinins positive
- Alveolar consolidation on chest radiograph
- Interstitial infiltrate on chest radiograph
- Lobar consolidation on chest radiograph
Findings suggestive of Pneumococcal pneumonia
Clinical manifestations
- Hemoptysis
- Fine rales
- Pleuritic chest pain
- Increased breath sounds
- Bronchial breath sounds
- Dullness on chest percussion
- Purulent sputum
- Shallow respiration
- Pectoriloquy
- Increased tactile fremitus
- Productive cough
- Egophony
- High grade fever
Laboratory abnormalities
- Pleural effusion (exudative)
- Respiratory alkalosis
- Parenchymal hyperlucency on chest radiograph
- Increased uptake on Gallium scan
- Unilateral diaphragm elevation on chest radiograph
- Alveolar consolidation on chest radiograph
- Lobar consolidation on chest radiograph
- Gram positive diplococci on sputum Gram stain
Findings suggestive of Pneumocystis carinii pneumonia
Clinical manifestations
- Immunosuppressive state
- Mediastinal emphysema
- Subcutaneous emphysema
- Hacking cough
- Progressive dyspnea
Laboratory abnormalities
- Respiratory alkalosis
- Serum beta-D-glucan elevated
- Alveolar consolidation on chest radiograph
- Lobar consolidation on chest radiograph
- Interstitial infiltrate on chest radiograph
Findings suggestive of Pulmonary embolism
Clinical manifestations
- Calf pain / swelling
- Decreased pulse pressure
- Dyspnea with normal chest X-ray
- Hemoptysis
- Hyperventilation
- Immobility
- Increased pulmonic component of heart sound
- Pleuritic chest pain
- Prior DVT
- Pulmonary hypertension
- Right ventricular heave
- Right ventricular hypertrophy
- Right-to-left shunt
- Substernal chest pain
- Tachypnea
- Thrombophlebitis
- Unilateral lower extremity edema
- Venous stasis
Laboratory abnormalities
- Atrial fibrillation
- Bone fracture
- Atelectasis on chest radiograph
- Lobar consolidation on chest radiograph
- Prominent pulmonary artery on chest radiograph
- Hampton's hump on chest radiograph
- D-dimer elevated
- Right ventricular enlargement on echocardiography
- Thrombus on echocardiography
- Hypocapnia
- Hypoxia
- Segmental perfusion defect on lung scan
- V/Q mismatch on lung scan
- Pleural effusion (exudative / bloody)
- RVH on ECG
- Right axis deviation on ECG
Findings suggestive of Streptococcal pneumonia
Clinical manifestations
- Pectoriloquy
- Bronchial breath sounds
- Empyema
- Erythema nodosum
- Purulent sputum
- Shallow respiration
- Increased tactile fremitus
- Pleuritic chest pain
- Egophony
Laboratory abnormalities
- Respiratory alkalosis
- Pleural effusion (exudative)
- Increased uptake on Gallium scan
- Gram-positive cocci in chains on sputum Gram stain
- Alveolar consolidation on chest radiograph
- Lobar consolidation on chest radiograph
Findings suggestive of Viral pneumonia
Clinical manifestations
- Pleuritic chest pain
- Bronchial breath sounds
- Influenza
- Fine rales
- Bronchovesicular breath sounds
Laboratory abnormalities
- Lymphocytosis
- Respiratory alkalosis
- Lobar consolidation on chest radiograph
- Interstitial infiltrate on chest radiograph
- ↑ Ferri, Fred (2011). Ferri's differential diagnosis: a practical guide to the differential diagnosis of symptoms, signs, and clinical disorders. Philadelphia, PA: Elsevier/Mosby. ISBN 978-0323076999.
- ↑ Siegenthaler, Walter (2007). Differential diagnosis in internal medicine: from symptom to diagnosis. Stuttgart New York: Thieme. ISBN 978-1588905512.
- ↑ Mesko, Dusan (2002). Differential diagnosis by laboratory medicine: a quick reference for physicians. Berlin New York: Springer-Verlag. ISBN 978-3540430575.
- ↑ Reeder and Felson's gamuts in radiology: comprehensive lists of roentgen differential diagnosis. Place of publication not identified: Springer. 2014. ISBN 978-1475781229.
- ↑ Burgener, Francis (2008). Differential diagnosis in conventional radiology. Stuttgart New York: Thieme. ISBN 978-1588902757.
- ↑ Gattuso, Paolo (2015). Differential diagnosis in surgical pathology. Philadelphia, PA: Saunders/Elsevier. ISBN 978-1455770137.
- ↑ "DXplain".