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	Edema	Tachycardia	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.	Ct scan shows Intense bronchiolar mural inflammation of cellular bronchiolitis results in centrilobular nodulesthat are usually associated with the tree-in-bud pattern and bronchial wall thickening
Asthma	-	Dry/Productive	-	+	-	+ Pulmonary edema	-	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	+ while walking	-	-	+	+	Routine lab tests in order to know the cause of the heart failure: Renal function tests including urinalysis and electrolytes assessment Complete blood count Thyroid studies specially in patients who are being treated with concomitant therapy with an agent such as amiodarone. Biomarkers: Natriuretic Peptides: BNP or NT-proBNP Biomarkers of myocardial Injury: Cardiac Troponin T or I Carbohydrate Antigen 125	EKG can be performed to detect the underlaying cause. Chest x ray shows cardiomegaly. Echocardiography is used to determine the stroke volume and to assess the heart failure.

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).