Editing Croup (section)

===Viral===
Viral croup or acute laryngotracheitis is most commonly caused by [[parainfluenza virus]] (a member of the [[Paramyxoviridae|paramyxovirus]] family), primarily types 1 and 2, in 75% of cases.<ref name=Croup09/> Other viral causes include [[influenza]] A and B, [[measles]], [[adenovirus]] and [[respiratory syncytial virus]] (RSV).<ref name=Cherry08/> Spasmodic croup is caused by the same group of viruses as acute laryngotracheitis, but lacks the usual signs of infection (such as fever, sore throat, and increased [[white blood cell count]]).<ref name=Cherry08/>  Treatment, and response to treatment, are also similar.<ref name=Croup09/>