Fever

Last updated: December 2023

Fever is defined as an axillary temperature higher than 37.5 °C.

Fever is frequently due to infection. In a febrile patient, first look for signs of serious illness then, try to establish a diagnosis.

Signs of severity

• Petechial or purpuric rash, meningeal signs, heart murmur, severe abdominal pain, dehydration.

• Signs of severe bacterial infection or sepsis: critically ill appearanceaCitation a.Critically ill appearing child: weak grunting or crying, drowsiness, difficult to arrouse, does not smile, disconjugate or anxious gaze, pallor or cyanosis, general hypotonia., hypothermia, altered level of consciousness, severe tachycardia, hypotension, tachypnoea, respiratory distress, seizures; a bulging fontanel in young children.
• Signs of circulatory impairment or shock: see Shock, Chapter 1. 

Infectious causes of fever according to signs and symptoms

• If the patient is ill appearingbCitation b.Critically ill appearing child: weak grunting or crying, drowsiness, difficult to arrouse, does not smile, unconjugate or anxious gaze, pallor or cyanosis, general hypotonia.and has a persistent fever, consider HIV infection and tuberculosis, according to clinical presentation.

Laboratory and other examinations

• Malaria rapid diagnostic test in endemic areas.
•  In case of circulatory impairment or shock: see Shock, Chapter 1.  
• Children 1 to 3 months with fever without a focus:
  • urine dipstick and urine culture, if available;
  • blood culture, if available;
  • full blood count (FBC), if available;
  • lumbar puncture (LP) if meningeal signs or signs of severe bacterial infection or sepsis, or failure of prior antibiotic treatment;
  • chest x-ray, if available, in case of signs of respiratory disease or severe infection or sepsis.
• Children > 3 months to 2 years with fever without a focus:
  • urine dipstick and urine culture, if available;
  • LP if meningeal signs or signs of severe bacterial infection or sepsis;

• chest x-ray, if available, if fever > 72 hours or signs of severe bacterial infection or sepsis;
• blood culture, if available, if fever > 72 hours or signs of severe bacterial infection or sepsis;
• FBC, if available, if fever > 72 hours or signs of severe bacterial infection or sepsis;
• other: according to clinical presentation.

• Children over 2 years with fever without a focus:
  • urine dipstick and urine culture, if available, if history of urinary tract infection or fever > 72 hours or signs of severe bacterial infection or sepsis;
  • LP if meningeal signs or signs of severe bacterial infection or sepsis;
  • chest x-ray, if available, if fever > 72 hours or signs of severe bacterial infection or sepsis;
  • blood culture, if available, if fever > 72 hours or signs of severe bacterial infection or sepsis;
  • FBC, if available, if fever > 72 hours or signs of severe bacterial infection or sepsis;
  • other: according to clinical presentation.
• Adults: according to clinical presentation.

Aetiological treatment

• Treat patients with a positive malaria test: see Malaria, Chapter 6.
• If the source of infection has been found: administer antibiotic treatment accordingly.

• If severe infection, sepsis, circulatory impairment or shock: hospitalise and immediately administer an empiric antibiotic treatment (see Shock, Chapter 1). Continue this treatment until the source of infection is found and adapt antibiotic treatment accordingly.

• If no source of infection is found, and there are no signs of severe infection, sepsis, circulatory impairment or shock, hospitalise for further investigations and monitoring:
  • Children 1 to 3 months;
  • Children > 3 months to < 2 years with negative urine dipstick (and negative urine culture if available).

• For malnourished children, see Severe acute malnutrition, Chapter 1.

• For patients with sickle cell disease, see Sickle cell disease, Chapter 12.

Symptomatic treatment

• Undress the patient. Do not wrap children in wet towels or cloths (not effective, increases discomfort, risk of hypothermia).
• Antipyretics may increase the patient’s comfort but they do not prevent febrile convulsions. Do not treat for more than 3 days with antipyretics.

paracetamol PO 
Children 1 month and over: 15 mg/kg 3 to 4 times daily (max. 60 mg/kg daily)
Adults: 1 g 3 to 4 times daily (max. 4 g daily)
or
ibuprofen PO
Children over 3 months and < 12 years: 5 to 10 mg/kg 3 to 4 times daily (max. 30 mg/kg daily)
Children 12 years and over and adults: 200 to 400 mg 3 to 4 times daily (max. 1200 mg daily)
or
acetylsalicylic acid (ASA) PO
Children over 16 years and adults: 500 mg to 1 g 3 to 4 times daily (max. 4 g daily)

Prevention of complications

• Encourage oral hydration. Continue frequent breastfeeding in infants.
• Look for signs of dehydration.
• Monitor urine output.

Notes:

• In pregnant or breast-feeding women use paracetamol only.
• In case of viral haemorrhagic fevers and dengue: acetylsalicylic acid and ibuprofen are contraindicated; use paracetamol with caution in the presence of hepatic dysfunction.