Internal Medicine: Head and Neck Examination

Head Examination

• Examination of eyebrows and lids is crucial
• Sclera, cornea, and pupils are key areas to inspect

Neck Examination

• Three main areas to focus on:
• Thyroid gland
• Lymph nodes (L.N)
• Pulsations

Measuring Body Temperature

• The lecturer, Dr. Mohamed Farouk, is a Lecturer of Tropical Medicine and Gastroenterology at New Valley University.

Importance of Measuring Body Temperature

• Identify the instruments used in measuring body temperature.
• Identify the normal range of body temperature.
• Describe the different abnormalities of body temperature.

Technique of Measuring Body Temperature

• The right approach: stand at the patient's right-hand side.
• Preparing for the examination and precautions:
  • Greet the patient, introduce yourself, take permission, and explain the procedure.
  • Ask the patient to sit comfortably.
  • Maintain confidentiality and respect for the patient.
  • The patient must not have hot or cold drinks or exercise 15 minutes before measuring temperature.

Instruments Used in Measuring Body Temperature

• Medical Thermometers:
  • Mercury Thermometer (Advantages: Gold standard, Accurate, Cheap; Disadvantage: Mercury toxicity if broken in the mouth).
  • Digital Electronic Thermometer (Advantages: Easy to use, Rapid, Cheap; Disadvantage: Less Accurate compared to Mercury type).
  • Digital Infrared Thermometer (Advantages: Very Rapid; Disadvantage: Expensive, Less Accurate compared to Mercury type).
  • Non-contact Infrared Thermometer (Thermometer Gun) (Advantages: Very Rapid, Non-Contact, useful in outbreak of emerging diseases; Disadvantage: Expensive, not 100% accurate compared to Mercury type).

Sites of Measuring Body Temperature

• Mouth (Standard Method)
• Axilla
• Rectum
• Ear (external auditory meatus)
• Forehead

Oral Temperature (from the mouth)

• Place the clinical thermometer after sterilization and shaking under the tongue for at least 3 minutes.
• The patient must breathe through the nose and keep the lips firmly closed during the observation.
• False low reading: mouth breathing, incomplete closure of mouth, leave the thermometer for too short time, ingest cold substances just before recording the temperature.
• False high reading: incomplete shaking of the thermometer, ingest hot drinks just before recording the temperature.
• Contraindications: infants, mouth breathing, convulsions, and coma.

Axillary Temperature

• The underarm must be dry prior to measurement.
• Sterilized clinical thermometer bulb or tip is inserted in the axilla with adducted arm for 3 minutes.
• The recorded temperature is 0.5°C lower than oral temperature.

Rectal Temperature

• Rectal temperature is the best approximation to core temperature.
• The lubricated sterilized thermometer tip or bulb is inserted into the rectum for 2 minutes.
• Indications: infant, comatose patient, unconscious, extremely ill patient, mouth breather.
• Do not use the same thermometer for both oral and rectal readings.

Normal Range of Body Temperature

• Normal range of body temperature (mouth): (36.5-37.2) °C.
• Rectal and ear temperature are 0.5 °C higher than in the mouth (oral temperature).
• In the axilla is 0.5 °C lower than in the mouth (oral temperature).
• Diurnal variation in temperature: lowest values are recorded in the early morning between 2 and 4 AM, with a maximum between 4 and 6 pm.

Abnormalities of Body Temperature

• Fever (Pyrexia): body temperature above normal (>37.2 °C).
• Causes of fever: infection, immunological disturbance, malignancy, drugs, brain injury, endocrine disturbances.
• Physiological causes of fever: after vigorous exercise, after hot water bath, after meals, ovulation, pregnancy, hot weather, infants.
• Hyperpyrexia: temperature > 41.5 °C.
• Causes of Hyperpyrexia: heat stroke, encephalitis, others.
• Hypothermia: core (rectal) temperature below 35 °C.
• Causes of Hypothermia: shock state, starvation, water immersion or near-drowning, alcohol intoxication, others.

Temperature Ranges in Centigrade and Grades of Fever

• Normal body temperature: (36.5-37.2) °C.
• Febrile: > 37.2 °C.
• Mild/low grade fever: 37.3-38 °C.
• Moderate grade fever: 38.1-39 °C.
• High-grade fever: 39.1-41.5 °C.
• Hypothermia: < 35 °C.
• Hyperpyrexia/hyperthermia: > 41.5 °C.

Types and Pattern (Course) of Fever

• Fevers can be classified into 3 types based on duration: acute, subacute, chronic fever.
• The course of fever has several patterns.