General Medical Training Manual - Community Medicine IV

Chapter 2: Electives Related to Community Medicine - Pediatrics

Section 3: Management of Fever in Children

Author: Wang Lianren

I. Mechanism of Fever

Body temperature is regulated by thermosensitive neurons in the hypothalamus. Exogenous pyrogens (e.g., infections, vaccines, biologics, tissue injury, malignancies, drugs, autoimmune diseases, and endocrine/metabolic disorders) or cytokines produced by inflammatory cells lead to the production of endogenous pyrogens, which stimulate the hypothalamus to secrete prostaglandin E2 (PGE2). This causes the thermoregulatory center (Zhongshu, GV7) to raise the body's temperature set point, resulting in fever to maintain the thermostat. Normal body temperature also exhibits diurnal variation, being lowest in the early morning (2-4 AM) and higher in the afternoon (14-18 PM) by about 0.5-0.8 degrees. Elevated body temperature helps reduce microbial reproduction and enhances neutrophil and interferon activity, making fever a regulatory and defensive response of the body. However, fever requires the production of excess heat, increasing oxygen consumption, carbon dioxide production, and cardiac output. This can be an unbearable burden for children with heart disease, chronic anemia, chronic lung disease, diabetes, or congenital metabolic disorders. Additionally, children aged six months to five years, especially those with epilepsy, are at risk of febrile seizures due to fever. Therefore, antipyretics are clinically administered to these children or those feeling discomfort from fever to alleviate symptoms, restore appetite, and promote recovery.

Generally, an axillary temperature above 38°C (100.4°F) or a rectal temperature above 38.5°C (101.3°F), or a temperature 0.5-0.7°C higher than usual, is considered fever. Electronic thermometers read about 0.1-0.3°C higher than mercury thermometers. Axillary temperature stabilizes in about 15 minutes, while rectal temperature stabilizes in about 5 minutes.

1. Characteristics of Fever:

(1) A single isolated spike: Not caused by infection but related to blood product transfusions, medications, or procedures.

(2) High fever above 41°C: Acute sexually transmitted infections, bacterial infections (especially Gram-negative sepsis), hypothalamic (Zhongshu, GV7) nervous system infections, intracranial hemorrhage, malignant hyperthermia, drug fever, or heat stroke.

(3) Low body temperature below 36°C: Sepsis, cold exposure, hypothyroidism, or excessive use of antipyretics.

(4) Relative bradycardia (temperature-pulse dissociation): Low pulse rate despite fever, suggesting typhoid fever, brucellosis, leptospirosis, or drug fever.

2. Presence of Accompanying Symptoms:

(1) Upper respiratory symptoms such as cough and runny nose.

(2) Mucosal changes in the conjunctiva, mouth, throat, tonsils, or eardrum.

(3) Skin changes such as rashes, bleeding, purpura, or jaundice. {|116|}

(4) Gastrointestinal symptoms such as abdominal pain, vomiting, and diarrhea: These are not necessarily signs of gastrointestinal diseases. Pneumonia can cause abdominal pain, and urinary tract infections in infants and young children can also lead to gastrointestinal symptoms.

(5) Urinary symptoms such as frequent urination, painful urination, hematuria, and cola-colored urine.

(7) Cyanosis, chest pain, palpitation (tachycardia), and other cardiovascular symptoms.

(8) Symptoms such as redness, swelling, heat, pain, and limited movement in bones, joints, and muscles.

III. Key Points of Examination

1. General condition and activity level: "Is the child less energetic than usual?", "Is there increased somnolence?"

2. Check vital signs: including confirmation of dehydration.

3. Auscultation and palpation of the chest and abdomen: including checking for lymphadenopathy and hepatosplenomegaly.

4. Neurological examination of infants and young children, including the anterior fontanelle and reflexes.

IV. Inquiry Considerations

1. Age

2. Past history: birth history, including prenatal history, vaccination

3. Family history: current health status of cohabiting family members, presence of hereditary diseases in the family

4. Present illness: degree and duration of fever, use of antipyretics

5. Attendance at kindergarten or daycare, and prevalence of infectious diseases

6. Living environment and presence of pets

7. Medication use

8. Recent travel and dietary content

9. Indoor environmental temperature (room temperature)

V. Management of Fever

1. Generally, if the body temperature is below 39°C, the child is active and has an appetite, antipyretics are not necessary. Antipyretics do not alter the course of infection but provide symptomatic relief. However, antipyretics should be given to children with chronic cardiopulmonary diseases, metabolic abnormalities, neurological diseases, or those at risk of febrile seizures.

3. Pay attention to the replenishment of Shuifen (CV9).

4. Use lukewarm water (not alcohol) at around 30°C to wipe the body with a towel or sponge.

5. Pharmacological treatment

The use of aspirin in children may harm the liver and brain, leading to Reye syndrome

(Reye syndrome), so aspirin should not be used as an antipyretic in children under 18 years of age.

(1) Acetaminophen

1. 10-15 mg per kilogram per dose, every 4-6 hours.

2. Peak blood concentration is reached about 1 hour after oral administration.

3. Overdose may cause liver failure.

4. Long-term use may lead to kidney damage.

(2) Ibuprofen

1. 5-10 mg per kilogram per dose, every 6-8 hours.

2. Possible side effects include stomach discomfort, upper gastrointestinal bleeding, and reduced renal blood flow.

(3) Diclofenac:

1. Available in oral and suppository forms.

2. 1 mg per kilogram per dose, every 8 hours.

3. Peak blood concentration is reached about 30 minutes to 1 hour after suppository administration.