About human parainfluenza viruses (HPIVs). Centers for Disease Control and Prevention. https://www.cdc.gov/parainfluenza/about/index.html. Accessed Jan. 7, 2019.

Kimberlin DW, et al. Parainfluenza viral infections. In: Red Book Online. 31st ed. Elk Grove Village, Ill.: American Academy of Pediatrics; 2018. https://redbook.solutions.aap.org. Accessed Jan. 7, 2019.

Petrocheilou A, et al. Viral croup: Diagnosis and a treatment algorithm. Pediatric Pulmonology. 2014;49:421.

Ali S, et al. Prehospital dexamethasone administration in children with croup: A medical record review. Emergency Medicine. 2018;10:141.

Ortiz-Alvarez O, et al. Acute management of croup in the emergency department. Pediatrics and Child Health. 2017;22:166.

Smith DK, et al. Croup: Diagnosis and management. American Family Physician. 2018;97:575.

Bagwell T, et al. Management of croup in the emergency department: The role of multidose nebulized epinephrine. Pediatric Emergency Care. In press. Accessed Jan. 7, 2019.

Use caution when giving cough and cold products to kids. U.S. Food and Drug Administration. https://www.fda.gov/drugs/resourcesforyou/specialfeatures/ucm263948.htm. Accessed Jan. 7, 2019.

Diphtheria and the vaccine (shot) to prevent it. Centers for Disease Control and Prevention. https://www.cdc.gov/diphtheria/materials.html. Accessed Jan. 7, 2019.

Protect your child against Hib disease. Centers for Disease Control and Prevention. https://www.cdc.gov/features/hibdisease/. Accessed Jan. 7, 2019.

Baughn JM (expert opinion). Mayo Clinic, Rochester, Minn. Jan. 23, 2019.

Bacterial tracheitis. Merck Manual Professional Version. https://www.merckmanuals.com/professional/pediatrics/respiratory-disorders-in-young-children/bacterial-tracheitis. Accessed Jan. 23, 2019.