Paediatric Fever & Infections

Fever is the body raising its own temperature in response to an infection. It is a sign that the immune system is working, and it is a symptom instead of an illness in itself. In children a temperature at or above 38 degrees Celsius is treated as a fever.

The great majority of childhood fevers are caused by viruses affecting the nose, throat, chest or gut, and those settle over three to five days without antibiotics. Bacterial infections are less common but matter more, and the two can look identical in the first day. Your doctor's task is to decide which is in front of them and to spot the small number of children who are becoming seriously unwell.

How high the temperature goes is a poor guide to how serious the cause is. A child with 39 degrees who drinks, plays between spikes and settles with paracetamol is usually less worrying than a child with 38 degrees who is limp, refusing fluids and breathing fast. Age changes the rules entirely: in a baby under three months, any fever is assessed urgently and in person, however well the baby looks.

Your doctor examines your child for two things at once: where the infection is, and how unwell your child is regardless of where it is.

Finding the source means looking at the ears, the throat and the tonsils, listening to the chest, feeling the abdomen, checking the neck for stiffness, examining the skin over the whole body with the clothes off, and looking at joints and limbs for anything your child will not move. In younger children the urine is often checked, since an infection there can present with fever and nothing else.

Judging how unwell your child is has its own set of observations: how alert and interested they are, whether they make eye contact and respond to you, the rate and effort of breathing, the colour of the skin and lips, how quickly colour returns after pressing on a fingertip, how moist the mouth is, and how many wet nappies there have been. Your doctor will ask how many days the fever has run, since a fever beyond five days changes the approach, and will ask about immunisations, recent travel and what is going around at home and at school. Tell them if a rash does not fade when a glass is pressed onto it.

A viral fever typically peaks for two to three days and is gone by day five. Appetite returns after the temperature does, and it may take a further week to come back fully. A cough often outlasts everything else by two to three weeks and can be entirely normal in a child who is otherwise well and active again.

Paracetamol and ibuprofen are given for discomfort instead of for the number on the thermometer. A child who is comfortable at 38.5 degrees does not need medicine. Fluids matter more than food in the first few days, and small amounts offered often work better than large amounts occasionally.

Where antibiotics are prescribed for a bacterial infection, expect improvement within forty-eight to seventy-two hours, and complete the course as directed. Your child can go back to school once they have been free of fever for twenty-four hours without medicine and are eating and playing normally.