Sandbox: Bronchiolitis DD

Bronchiolitis should be differentiated with other diseases that cause cough and dysnea.

Diseases	Symptoms			Signs		Diagosis
	Fever	Cough	Chest pain	Wheezes	Crackles	Lab tests	Imaging
Bronchiolitis	+/-	Dry		+	+	No specific lab findings Viral tests like ELISA and immunoassays may be done in case of RSV infection. Pulmonary function test is performed to exclude other lung diseases.	No specific imaging findings.
Asthma	-	Dry/Productive		+	-	Lab tests are not specific for asthma but they are performed to exclude other diseases. Serum examination shows elevated level of esoinophils due to allergy.	CT scan shows dilated bronchi, bronchial wall thickening and air trapping.
COPD	+	Productive
Bacterial pneumonia	+	Productive
Pulmonary embolism	-	Bloody	+
Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia	-	Dry	-	+	-	Pulmonary function test shows obstructive lung disease	CT scan shows multiple nodules , ground glass appearance and bronchiectasis.
Tuberculosis	+	Bloody
Interstitial pneumonitis (Hamman - Rich syndrome)	+	Productive
Foreign body aspiration	-	Dry
Sarcoidosis	-	Dry
Pertussis	+	Dry		-	-	Nasopharyngeal swab Culture Serology to detect pertussis toxin.	No remarkable imaging findings.
Congestive heart failure	-	Dry/Productive

Differential diagnosis of bronchiolitis: Asthma, COPD, sarcoidosis, pneumonia, heart failure, DIPNECH, foreign body inhalation, pulmonary embolism and GERD (in case it is associated with asthma).