Fever: What you need to know

1. The body’s response when the body temperature is high (fever state)?

When body temperature exceeds the normal range, the body will react to increase the body temperature to fight against pathogens. This mechanism happens through two ways:

• Increased heat production: The body increases metabolic activities, and increases heat production through activities such as shivering, muscle contraction, and increased breathing.
• Heat retention: The body reduces heat loss through the skin by constricting blood vessels under the skin, reducing sweat production, and reducing water evaporation.

2. How do endogenous pyrogens affect the body?

Endogenous pyrogens, mainly prostaglandin E2 (PGE2), are released from immune cells when the body encounters pathogens. PGE2 will affect the hypothalamus, the body’s thermoregulatory center, leading to:

• Increased heat production: Stimulates the body to produce more heat.
• Set point adjustment: Change the normal body temperature threshold, bringing the body to a higher temperature to kill pathogens.

3. Characteristics of thermoregulation in children:

Children have an immature thermoregulation system, easily affected by external factors. This leads to some distinct characteristics:

• Immature thermoregulatory center: The ability to regulate body temperature is not stable and is easily changed.
• Large skin surface area compared to body weight: Easily lose heat through the skin, especially in cold weather.
• Strong heat loss through evaporation: Due to a large skin surface area, children are easily dehydrated when they have a fever, leading to a serious risk of dehydration.
• Always active, produce a lot of heat: Children are usually more active than adults, produce more heat, and are easily febrile when infected.
• Easy to have endocrine-nervous disorders, especially during puberty: Affecting the ability to regulate body temperature.
• Congenital diseases causing thermoregulation disorders: Some congenital diseases can affect the child’s ability to regulate body temperature.

4. When is body temperature considered elevated?

• Rectal temperature > 38 degrees Celsius.
• Oral temperature > 37.6 degrees Celsius.
• Axillary temperature > 37.4 degrees Celsius.

5. What is hyperthermia?

Hyperthermia is a condition where the body temperature exceeds the normal range.

6. What is hypothermia?

Hypothermia is a condition where the body temperature is lower than the normal range.

7. What is fever?

Fever is a condition where the body temperature is elevated, exceeding the normal range, often due to the body’s response to infection or other pathogens.

8. Fever classification:

According to the temperature measured rectally:

• Mild fever: 38 – 39 degrees Celsius.
• Moderate fever: 39.1 – 40 degrees Celsius.
• High fever: 40.1 – 41 degrees Celsius.
• Very high fever: > 41.1 degrees Celsius – This is an emergency situation and needs to be treated immediately.

According to the course of time:

• Short-term fever: Fever for a short time, usually due to benign viruses, self-healing after 2-3 days. No special treatment is needed.
• Long-term fever: Continuous fever every day for 2 weeks or more, usually due to chronic infections, autoimmune diseases, malignancies.
• Persistent fever: Fever for many days but not continuously, there are days without fever.
• Continuous high fever (plateau fever): Temperature is always > 39 degrees Celsius, morning-evening fluctuation is not more than 1 degree Celsius.
• Cyclic fever: Similar fever episodes occur periodically, completely normal between episodes.
• High fluctuating fever: Intermittent high fever, sometimes without fever.
• Undulating fever: Body temperature gradually increases, gradually decreases to normal, then fever recurs after a period of time. Fever due to spirochetes.
• Relapsing fever: After each fever episode of 3-7 days, there is a non-fever episode, followed by a fever episode.

9. Benefits of fever:

• Increases immune response and immune response: Fever helps the body strengthen its ability to fight pathogens.
• Increases bone marrow cell activity: Stimulates the production of white blood cells, strengthens resistance.
• Inhibits bacterial growth and kills pathogens: High temperature can inhibit bacterial growth and kill pathogens.

10. Harmful effects of fever:

• Increases hypersensitivity reactions, shock: Can cause anaphylactic shock, life-threatening.
• Increases the process of degeneration, destruction, reduces zinc and iron in the blood: Causes weakness, reduced resistance.
• Dehydration, electrolyte disturbance: Due to increased sweating, the body is easily dehydrated and electrolyte disturbance.
• Febrile seizures: Especially dangerous for young children.
• Neurological disorders: Can cause confusion, delirium, coma.
• Loss of appetite, exhaustion: Causes weakness, reduced resistance.
• Heart failure, respiratory failure when fever is high and prolonged: Causes damage to internal organs.

11. How to measure temperature:

Axilla:

• Dry the armpit.
• Shake the thermometer down below 35 degrees Celsius.
• Place in the armpit, hold firmly for 10 minutes.

Mouth:

• Do not eat or drink for at least 10 minutes before measuring.
• Shake the thermometer down below 35 degrees Celsius.
• Place under the tongue, for young children place at the corner of the mouth.
• Read after 5 minutes.

12. Causes of fever:

• Infection: The most common cause of fever.
• Blood diseases, malignancies: Cause prolonged fever.
• Connective tissue diseases: Cause prolonged fever.
• Allergies, drugs, nervous disorders: Can cause fever.

13. Etiology of acute fever:

Organ infections:

• Viruses: Dengue fever, influenza, measles, chickenpox, viral hepatitis.
• Bacteria: Pneumonia, otitis media, pharyngitis.
• Fungi: Skin fungal infections, vaginal fungal infections.

14. Infections causing prolonged fever:

• Infective endocarditis: Inflammation of the inner lining of the heart.
• Tuberculosis: Bacterial infection caused by Mycobacterium tuberculosis.
• Typhoid fever: Bacterial infection caused by Salmonella Typhi.
• CMV, EBV: Common viruses causing infection, can cause prolonged fever.

15. Autoimmune diseases causing prolonged high fever:

• Lupus: Autoimmune disease affecting many organs.
• Rheumatoid arthritis: Autoimmune disease affecting joints.

16. Malignancies causing prolonged high fever:

• Leukemia: Cancer of the blood.
• Lymphoma: Cancer of the lymphatic system.

17. Principles of treatment and care for children with fever:

• Dress lightly, loosely, and lie in a cool place: Avoid wearing too many clothes, keep the child cool.
• Warm compress: Warm compress forehead, armpit, groin to reduce body temperature.
• Give liquid food and drink plenty of water: Supplement water and electrolytes to prevent dehydration.
• Antipyretics: Not the first solution, but should be used when axillary temperature > 38.5 degrees Celsius.
  • Paracetamol: Dosage 10-15 mg/kg/dose, every 4-6 hours, maximum 60 mg/kg/day.
  • Ibuprofen: Dosage 5-10 mg/kg/dose, every 6-8 hours.

18. Things to avoid when a child has a fever:

• Place the child in front of a fan or air conditioner: Can cause the child to get cold, increasing the risk of getting cold.
• Let the child get cold: Avoid letting the child get cold, keep the child warm.
• Wake the child up to measure temperature, unless the child sleeps unusually long: Can cause the child to be startled and scared.

19. How to use paracetamol to reduce fever:

• Oral: Give the child paracetamol according to the appropriate dosage.
• Rectal: Give the child rectal antipyretics, suitable for young children.

20. Children are at risk of paracetamol poisoning when using:

• >= 30 mg/kg/dose or >= 60 mg/kg/24h or high dose for a long time.

21. How to use ibuprofen to reduce fever:

• Dosage 5-10 mg/kg/dose, every 6-8 hours.
• Use paracetamol and ibuprofen alternately every 4-6 hours for good effect.

22. Side effects of ibuprofen:

• Dyspepsia, gastrointestinal bleeding, reduced renal perfusion, aseptic meningitis, liver toxicity.

23. Warning signs to watch out for when a child has a fever:

• Unable to drink, refuses to breastfeed: Signs of dehydration, weakness.
• Cold hands and feet, fast pulse, difficult to catch, less urination: Signs of dehydration, shock.
• Difficulty breathing: Signs of respiratory infection.
• Severe vomiting, severe diarrhea: Signs of dehydration, gastrointestinal infection.
• Seizures: Dangerous signs, need immediate treatment.
• Lethargy, difficult to wake up: Signs of severe infection.
• Rash, blisters, heavy bleeding: Signs of blood infection, shock.
• Headache, fussiness, agitation: Signs of meningitis.

24. Note when children live in or travel to a malaria area within:

• The last 6 months.

25. Note when children live in or travel to a dengue fever area:

• 2 weeks.

26. Note when children have measles within:

• The last 3 months.

27. Age group commonly encountered with aseptic meningitis:

• Under 3 years old.

28. Types of bacteria causing aseptic meningitis most commonly encountered:

• Pneumococcus, Hib, meningococcus.

29. Newborns and young children commonly have aseptic meningitis due to infection:

• Intestinal bacteria (E.Coli), Proteus, Klebsiella, Listeria, Group B Streptococcus.

30. Risk factors due to constitutional causes:

• Male > Female: Males are more susceptible to meningitis than females.
• Premature infants, malnutrition: Premature infants and malnutrition are more susceptible to meningitis.
• Splenectomy: Susceptible to pneumococcal, Hib, gram-negative bacilli meningitis.

31. Routes of entry of bacteria causing aseptic meningitis:

• Blood, lymph, contiguous.

32. Mechanism to overcome resistance of bacteria causing aseptic meningitis:

• Able to adhere and localize on the surface of the mucosal epithelium of the patient: Bacteria have the ability to adhere to the mucosa.
• Penetrate and survive in the bloodstream: Bacteria can penetrate the blood and survive.
• Overcoming the blood-brain barrier: Bacteria can cross the blood-brain barrier and enter the brain.
• Able to live in cerebrospinal fluid: Bacteria can survive and reproduce in cerebrospinal fluid.

Note:

• This article provides general information about fever and aseptic meningitis.
• This information cannot replace the advice of a doctor.
• When a child has a fever, it is necessary to take the child to the doctor for timely diagnosis and treatment.

Let me know if you would like me to clarify anything else.