An article published in the Clinical Manual of Fever in Children discussed that infection of the upper airways is the most common acute illness evaluated in the outpatient setting. Acute respiratory illness remains a leading cause of death globally—accounting for nearly 1.5-2 million deaths annually in children younger than 5 years of age.Such infections are usually caused by viruses including rhinoviruses, influenza viruses, parainfluenza and respiratory syncytial viruses. Influenza – the only viral infection preventable by vaccination, generally occurs during the winter epidemic season. Whereas, bacterial infection, for example, acute rhinopharyngitis is uncommon and usually presents with either persistent symptoms—lasting over a week—or a worsening course after an initial improvement, or acute onset with high fever and inflammatory changes of the pharynx.

The authors also stated that fever is common in both, bacterial and viral gastroenteritis. High fever is commonly present in many bacterial infections, while it is almost absent or low-grade in others. Meanwhile, several febrile conditions cause diarrhea and need to be differentiated.

In CNS infection, fever is the most common presenting symptom in children who have crossed the neonatal phase. In meningococcal disease (MCD), fever is the first symptom in children under 5 years and the majority, developed fever at some point.

In addition, viral exan thems are common causes of febrile illness in children—more than 50 viral agents are known to cause a rash. 

High fever is associated with a greater incidence of serious bacterial diseases such as pneumonia or meningitis. On the other hand, if fever does not have an evident source, urinary tract infection should be considered. 

This article reported that with the advent of widespread vaccinations against bacterial meningitis, such as Hib, and against meningococci and pneumococci, the incidence of meningitis has markedly reduced. Moreover, young children with malaria may present with irregular fever, unlike typical paroxysms of fever, occurring particularly in early falciparum infection.

Source: Clinical Manual of Fever in Children.2019 Jan 2 : 85–140.doi: 10.1007/978-3-319-92336-9_5