Fever is usually a response to infection or inflammation and may form part of the body’s defence against infection. The height of the fever does not necessarily correlate with the severity of the illness and fever can commonly occur in children with minor illnesses. The child often appears flushed as blood vessels in the skin vasodilate in an attempt to lose heat. Some young children experience febrile convulsions if their temperature rises very rapidly (see Chapter 41).
Temperature can be measured rectally, orally or in the axilla using a thermometer, or using a thermal device in the ear canal or skin. Fever is defined as an axillary temperature above 37 °C. It can be treated by undressing the child so heat is lost through the skin. Sponging with tepid water can help. Fever needs treatment with antipyretics such as paracetamol or ibuprofen when it causes discomfort—aspirin should not be used under the age of 12 years as it can lead to severe liver failure (Reye’s syndrome, see Chapter 48). Persistent or recurrent fever is discussed in Chapter 22.
Fever in Young Infants
Fever in infants less than 8 weeks old must be taken seriously as signs of sepsis at this age can be non-specific. Significant fever should always prompt a careful examination and investigations. If ill, infants require a full infection screen including urine culture, chest radiograph and possibly lumbar puncture.
Viral Upper Respiratory Tract Infections
Upper respiratory tract infections (URTIs) are extremely common in children, occurring on average 6–8 times a year. They are especially common when toddlers start nursery and on starting school when children become exposed to a large number of viral infections to which they have no immunity. Symptoms include coryza (runny nose), acute pharyngitis and fever. In acute pharyngitis the tonsillar fauces and palate are inflamed, cervical lymph nodes may be enlarged and the tympanic membranes inflamed. Young infants may have difficulty breathing and feeding because they are obligate nose breathers. Treatment is symptomatic, with antipyretics such as paracetamol. Saline drops may improve nasal congestion in infants. The infection usually lasts 3–4 days. Antibiotics should not be given.
Tonsillitis is usually viral in origin. In older children the commonest bacterial organism is group A beta-haemolytic streptococcus. Symptoms include sore throat or dysphagia and usually a fever. There is often tender cervical lymphadenopathy, which may cause neck stiffness, and associated adenitis in the mesenteric nodes may cause abdominal pain. On examination the tonsils are enlarged and acutely inflamed. In bacterial tonsillitis the breath may smell offensive and there may be a white exudate, although this is not always a reliable sign. Exudates can also occur with infectious mononucleosis (glandular fever) and with diphtheria (now very rare). Acute tonsillitis should be distinguished from hypertrophied but non-inflamed tonsils which are common in preschool children.
Most children do not require antibiotics and can be managed with saline gargles/throat lozenges and paracetamol. If bacterial infection is suspected this should ideally be confirmed by a throat swab. Streptococcal tonsillitis should be treated with benzyl penicillin for 10 days.
Complications of tonsillitis are rare and include otitis media, peritonsillar abscess (quinsy) and poststreptococcal glomerulonephritis. Chronically enlarged tonsils can cause upper airway obstruction and obstructive sleep apnoea. This is an indication for tonsillectomy.
Glandular fever is due to Epstein–Barr virus (EBV) infection and is usually a self-limiting infection in adolescents. It presents with low-grade fever, malaise, pharyngitis and cervical lymphadenopathy. Occasionally, hepatosplenomagaly and jaundice may occur. Peripheral leucocytosis with atypical lymphocytes and a positive agglutination test (monospot) are diagnostic. Most adults show serological evidence of EBV infection. The symptoms may last many weeks. Amoxicillin is contraindicated as it will cause a maculopapular rash in EBV infection.
Acute Otitis Media
Otitis media is very common, especially in young children and can occur in babies. The commonest causes are Streptococcus pneumoniae, Haemophilus influenzae and viruses. It is especially common when there is eustachian tube dysfunction, which occurs as a result of URTIs, obstruction from enlarged adenoids, cleft palate and in Down’s syndrome. Symptoms include fever, deafness and pain in the ear. The child may be irritable and pull at the ear, although infection may also be asymptomatic. Examination shows a red, inflamed and bulging tympanic membrane, with loss of the light reflex. Most cases resolve spontaneously and a trial of symptomatic treatment (paracetamol) for 72 hours is recommended before considering antibiotics. Bacterial otitis media is shortened by treatment with amoxicillin. Prognosis is generally good even if the tympanic membrane has perforated.
Complications include conductive deafness, mastoiditis and secretory otitis media (glue ear)—a thick, glue-like exudate in the middle ear. In secretory otitis media the tympanic membrane looks thickened and retracted with an absent light reflex. If there is significant hearing loss, ventilation tubes (grommets) may be inserted through the tympanic membrane to allow the middle ear to drain. They often fall out after a period of months to years and their use is controversial; but they are indicated if there is language delay secondary conductive deafness due to glue ear.
- Fever is very common in children, and can usually be managed by simple cooling and paracetamol.
- Any ill child with high fever must be examined carefully to exclude serious infections such as meningitis, urinary tract infection or pneumonia.
- Fever in babies less than 8 weeks old must be taken seriously.
- Otitis media and tonsillitis are common causes of fever in young children.
- Most fevers are due to non-specific viral infections or URTIs.