This is one of the most common and difficult calls in general practice, emergency medicine and acute paediatrics: when to treat a child as a lower respiratory tract infection.
It’s important because we don’t want to miss a diagnosis of LRTI/ pneumonia, yet overtreating is bad medicine. It’s difficult because most children with an upper respiratory tract infection will have a cough and fever, and because the parents will be worried about the possibility of LRTI.
To make things worse, any child with uncomplicated URTI could later develop LRTI. Not often, but often enough that it can influence our decision making. So how do we get it right?
I think that it is a question of rule in/ rule out. There are many elements to the assessment but there is one feature that determines whether the default is to assume that there is no LRTI and whether the default is to assume that there is a LRTI. That feature is respiratory abnormality.