Asthma differential diagnosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Philip Marcus, M.D., M.P.H. [2] Associate Editor(s)-in-Chief:

## Overview[edit | edit source]

Asthma must be clinically differentiated from other conditions that cause recurrent cough and wheezing such as viral bronchiolitis, chronic obstructive pulmonary disease, congestive heart failure, vocal cord dysfunction, ACE inhibitors use and allergic rhinitis.[1][2]

## Differentiating Asthma from other Diseases[edit | edit source]

* Asthma must be differentiated from other respiratory and cardiac diseases that can cause the same clinical manifestations like cough and dyspnea. These diseases include Bronchiolitis, COPD, pneumonia, congestive heart failure, diffuse idiopathic neuroendocrine cell hyperplasia, tuberculosis, pertussis, foreign body aspiration, pulmonary embolism and Harmann-Rich syndrome.[1][3][4][5][6]

Diseases  | Symptoms  |  | Signs  | Diagosis

|
|
|
|

Fever  | Cough  | Chest pain  | Wheezes  | Crackles  | Tachycardia  | Lab tests  | Imaging
Asthma | \-  | Dry/Productive  | \-  | \+  | \-  | \-  |

* Lab tests to exclude other diseases
* Serum examination shows elevated level of eosinophils due to allergy

* CT scan shows:
* Dilated bronchi
* Bronchial wall thickening
* Air trapping

Bronchiolitis | +/-  | Dry  | \-  | \+  | \+  | +/-  |

* ELISA and immunoassays may be done in case of RSV infection
* Pulmonary function test to exclude other lung diseases[7]

* CT scan shows:
* Intense bronchiolar mural inflammation
* bronchial wall thickening
* Centrilobular nodules with tree-in-bud pattern

COPD | \+  | Productive  | \-  | \+  | \+  | \+  |

* Spirometry: FEV1/FVC < 70%
* Arterial blood gases: hypoxemia and hypercapnia
* Sputum culture

* EKG may show:
* P pulmonale
* right ventricular hypertrophy
* Narrow QRS[8]
* CT scan is more sensitive in diagnosing COPD than X ray

Bacterial pneumonia | \+  | Productive  | \+  | \+  | \+  | +/-  |

* Diagnosis depends on presentation and physical examination
* Laboratory tests
* arterial blood gases may show hypoxia and acidosis
* Sputum culture

* X ray is performed to detect:
* pleural effusion
* Inflitrates within the lungs.
* CT scan shows:
* Consolidation
* Ground glass appearance

Pulmonary embolism | +/-  | Bloody  | \+  | \+  | \+  | \+  |

* Arterial blood gases may show:[9]
* Hypoxemia
* Hypocapnia
* Respiratory alkalosis
* Increased alveolar-arterial gradient
* D-dimer assay to rule out other diseases like DVT
* Hypercoagulability tests for patients with:
* Unprovoked venous thrombosis at an early age (< 40 years)
* Family history of VTE syndromes
* Routine blood tests are non specific

* CT pulmonary angiography is the gold standard imaging to diagnose pulmonary embolism. CT may show:
* Acute:Centrally located thrombus occluding the vessel
* Chronic:Eccentric changes in the vessel wall, recanalization in the thrombous and arterial web
* EKG is not specific or sensitive in PE diagnosis but it may show:
* T wave inversion
* P pulmonale
* sinus tachycardia
* Chest X ray to exclude other differentials

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia[10] | \-  | Dry  | \-  | \+  | \-  | \-  |

* Pulmonary function test shows obstructive lung disease

* CT scan may show:
* Multiple nodules
* Ground glass appearance
* Bronchiectasis.

Tuberculosis | \+  | Bloody  | \+  | \-  | \-  | \-  |

* Sputum culture:
* Three successive positive culture for M. tuberculosis confirms the diagnosis[11]
* Presence of acid fast bacilli in sputum smear indicates high extent tuberculosis

* Chest X ray is an important diagnostic imaging procedure in TB diagnosis. X ray may show:[12]
* Parenchymal infilration
* Hilar adenopathy
* Nodules
* Pleural effusion

* CT scan may show:[13]
* Micronodules
* Cavitation
* Consolidation
* Interlobular septal thickening
* EKG may have abnormalities in case pleural effussion associated with TB.

Interstitial pneumonitis (Hamman - Rich syndrome)  | \+  | Productive  | \-  | \-  | \+  | \-  |

* Arterial blood gases may show:
* hypoxemia
* PaO2/FiO2 less than 200 mmHg indicating acute respiratory distress syndrome
* Other lab tests are done to exclude other diseases

* Chest X ray may show:
* Bilateral airway opacification
* CT scan may show
* Ground glass appearance.
* Bronchoscopy to exclude other causes such as:
* alveolar hemorrhage
* lymphoma.
* Lung biopsy is done:
* In unclear cases; to confirm acute interstitial pneumonitis
* Exclude other causes of ARDS

Foreign body aspiration | \+  | Bloody  | \+  | \+  | \-  | \-  |

* Lab tests to evaluate the ventilation function

* Chest X ray shows:
* Hyperinflation
* Mediastinal shift
* Aatelectasis

Pertussis | \+  | Dry  |  | \-  | \-  | \-  |

* Nasopharyngeal swab for PCR testing
* Sputum culture
* Serology to detect pertussis toxin[14][15]

* No remarkable imaging findings

Congestive heart failure | \-  | Dry/Productive  | \+ while walking  | \-  | \-  | \+  |

* Routine lab tests to identify the cause of the heart failure:
* Renal function tests including urinalysis and electrolytes
* Complete blood count
* Thyroid studies in patients being treated with concomitant therapy such as amiodarone
* Biomarkers:
* BNP or NT-proBNP[16]
* Cardiac Troponin T or I
* Carbohydrate Antigen 125[17]

* EKG to detect underlying cause
* Chest x ray shows cardiomegaly
* Echocardiography is done:
* To determine stroke volume
* To assess type of heart failure[18]

* Although, many cases of recurrent cough and wheezing in children and adults are due to asthma, other conditions are often misdiagnosed as asthma.[1][6][5][4][3]

### Adults[edit | edit source]

* Chronic obstructive pulmonary disease (COPD)
* Hyperventilation syndrome and panic attacks
* Congestive heart failure
* Pulmonary embolism
* Laryngeal dysfunction
* Pulmonary aspiration
* Mechanical obstruction of the airways (benign and malignant tumors)
* Pulmonary infiltration with eosinophilia
* Diffuse parenchymal lung diseases
* Cough, secondary to drugs (ACE inhibitors)[2]
* Vocal cord dysfunction[6]
* Pharyngitis

### Infants & Children[edit | edit source]

##### Upper airway diseases[edit | edit source]

* Allergic rhinitis and sinusitis[6]

##### Obstructions involving large airways[edit | edit source]

* Foreign body in trachea or bronchus
* Vocal cord dysfunction
* Vascular rings or laryngeal webs
* Laryngotracheomalacia, tracheal stenosis, or bronchostenosis
* Enlarged lymph nodes or tumor[6]

##### Obstructions involving small airways[edit | edit source]

* Viral bronchiolitis or obliterative bronchiolitis
* Cystic fibrosis
* Bronchopulmonary dysplasia[6]

##### Other causes[edit | edit source]

* Congenital heart diseases
* Recurrent cough not due to asthma
* Aspiration from swallowing mechanism
* Gastroesophageal reflux[6]

## References[edit | edit source]

1. ↑ 1.0 1.1 1.2 Liu WY, Yu Q, Yue HM, Zhang JB, Li L, Wang XY; et al. (2016). "[The distribution characteristics of etiology of chronic cough in Lanzhou]". Zhonghua Jie He He Hu Xi Za Zhi. 39 (5): 362–7. doi:10.3760/cma.j.issn.1001-0939.2016.05.006. PMID 27180590.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
2. ↑ 2.0 2.1 Wrona W, Budka K, Filipiak KJ, Niewada M, Wojtyniak B, Zdrojewski T (2016). "Health outcomes and economic consequences of using angiotensin-converting enzyme inhibitors in comparison with angiotensin receptor blockers in the treatment of arterial hypertension in the contemporary Polish setting". Kardiol Pol. 74 (9): 1016–24. doi:10.5603/KP.a2016.0055. PMID 27112942.CS1 maint: Multiple names: authors list (link)
3. ↑ 3.0 3.1 Lin L, Chen Z, Cao Y, Sun G (2017). "Normal saline solution nasal-pharyngeal irrigation improves chronic cough associated with allergic rhinitis". Am J Rhinol Allergy. 31 (2): 96–104. doi:10.2500/ajra.2017.31.4418. PMID 28452705.CS1 maint: Multiple names: authors list (link)
4. ↑ 4.0 4.1 Jiang S, Li J, Zeng Q, Liang J (2017). "Pulmonary artery intimal sarcoma misdiagnosed as pulmonary embolism: A case report". Oncol Lett. 13 (4): 2713–2716. doi:10.3892/ol.2017.5775. PMC 5403205. PMID 28454456.CS1 maint: Multiple names: authors list (link)
5. ↑ 5.0 5.1 Mosley JD, Shaffer CM, Van Driest SL, Weeke PE, Wells QS, Karnes JH; et al. (2016). "A genome-wide association study identifies variants in KCNIP4 associated with ACE inhibitor-induced cough". Pharmacogenomics J. 16 (3): 231–7. doi:10.1038/tpj.2015.51. PMC 4713364. PMID 26169577.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
6. ↑ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 Environmental Triggers of Asthma. Differential Diagnosis of Asthma. Environmental Health and Medicine Education. Agency for Toxic Substances and Disease Registry. Available at: http://www.atsdr.cdc.gov/csem/csem.asp?csem=32&po=5. Accessed on February 25, 2016
7. ↑ Ghanei M, Tazelaar HD, Chilosi M, Harandi AA, Peyman M, Akbari HM; et al. (2008). "An international collaborative pathologic study of surgical lung biopsies from mustard gas-exposed patients". Respir Med. 102 (6): 825–30. doi:10.1016/j.rmed.2008.01.016. PMID 18339530.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
8. ↑ Lazović B, Svenda MZ, Mazić S, Stajić Z, Delić M (2013). "Analysis of electrocardiogram in chronic obstructive pulmonary disease patients". Med Pregl. 66 (3–4): 126–9. PMID 23653989.CS1 maint: Multiple names: authors list (link)
9. ↑ Cvitanic O, Marino PL (1989). "Improved use of arterial blood gas analysis in suspected pulmonary embolism". Chest. 95 (1): 48–51. PMID 2491801. Retrieved 2012-04-30. Unknown parameter `|month=` ignored (help)
10. ↑ Nassar AA, Jaroszewski DE, Helmers RA, Colby TV, Patel BM, Mookadam F (2011). "Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia: a systematic overview". Am J Respir Crit Care Med. 184 (1): 8–16. doi:10.1164/rccm.201010-1685PP. PMID 21471097.CS1 maint: Multiple names: authors list (link)
11. ↑ Drobniewski F, Caws M, Gibson A, Young D (2003). "Modern laboratory diagnosis of tuberculosis". Lancet Infect Dis. 3 (3): 141–7. PMID 12614730.CS1 maint: Multiple names: authors list (link)
12. ↑ Riccardo Piccazzo, Francesco Paparo & Giacomo Garlaschi (2014). "Diagnostic accuracy of chest radiography for the diagnosis of tuberculosis (TB) and its role in the detection of latent TB infection: a systematic review". The Journal of rheumatology. Supplement. 91: 32–40. doi:10.3899/jrheum.140100. PMID 24788998. Unknown parameter `|month=` ignored (help)
13. ↑ Jeong Min Ko, Hyun Jin Park & Chi Hong Kim (2014). "Pulmonary Changes of Pleural Tuberculosis: Up-to-Date CT Imaging". Chest. doi:10.1378/chest.14-0196. PMID 25086249. Unknown parameter `|month=` ignored (help)
14. ↑ Pertussis (whooping coug). Diagnosis confirmation. CDC.gov. Accessed on June 22, 2017
15. ↑ Pertussis (whooping cough). Specimen collection. CDC.gov. Accessed on June 22, 2017
16. ↑ Yancy CW, Jessup M, Bozkurt B, Butler J, Casey DE, Drazner MH, Fonarow GC, Geraci SA, Horwich T, Januzzi JL, Johnson MR, Kasper EK, Levy WC, Masoudi FA, McBride PE, McMurray JJ, Mitchell JE, Peterson PN, Riegel B, Sam F, Stevenson LW, Tang WH, Tsai EJ, Wilkoff BL (2013). "2013 ACCF/AHA guideline for the management of heart failure: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines". J. Am. Coll. Cardiol. 62 (16): e147–239. doi:10.1016/j.jacc.2013.05.019. PMID 23747642.
17. ↑ D'Aloia A, Vizzardi E, Metra M (2016). "Can Carbohydrate Antigen-125 Be a New Biomarker to Guide Heart Failure Treatment?: The CHANCE-HF Trial". JACC Heart Fail. 4 (11): 844–846. doi:10.1016/j.jchf.2016.09.001. PMID 27810078.CS1 maint: Multiple names: authors list (link)
18. ↑ Agha SA, Kalogeropoulos AP, Shih J, Georgiopoulou VV, Giamouzis G, Anarado P, Mangalat D, Hussain I, Book W, Laskar S, Smith AL, Martin R, Butler J (2009). "Echocardiography and risk prediction in advanced heart failure: incremental value over clinical markers". J. Card. Fail. 15 (7): 586–92. doi:10.1016/j.cardfail.2009.03.002. PMID 19700135.

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