Fever
Fever or Pyrexia means Increase in Body Temperature than Normal. In this Article we will cover the Causes, Mechanism of Fever, Fever Types, Algor Mortis.
Brief Overview of the Articles / Contents Table -
1. Causes of Fever
2. Mechanism of Fever
3. Phases of Fever
4. Types of Fever
5. Algor Mortis
1. Low Pyrexia = 99° - 100° F
2. Moderate Pyrexia = 100° – 103° F
3. High Pyrexia = 103° - 105° F
4. Hyperthermia = Equal or More than
105° F
5. Hyper Pyrexia >105° F
6. Euthermia = 98.6° F
7. Hypothermia <95° F
8. Subnormal Temperature = 95 - 98° F
Causes of Fever –
When there is Some Infection or Inflammation , It causes Pyrogens to release in the body
which causes Hypothalamus to increase the Body Temperature.
Phases of Fever –
1. Onset /
Invasion –
A Period when body temperature rises Suddenly / Gradually
2. Fastigium
/ Stadium –
A Period when body temp. reaches to
maximum level and remain fairly constant.
3. Defervesence –
A Period when body temp. returns to Normal.
It is of 2 types –
A. Crisis – Sudden Return to Normal.
·
True Crisis –
Temp. returns to Normal and Patient’s Condition Improves.
·
False Crisis –
Temp. returns to Normal and Patient’s Condition does not improve.
B. Lysis – Temp. returns in Zig-Zag
manner in 2-3 Days / 1 Week with improvement in Patient’s Condition.
Types of Fever / Febrile Period –
1. Continuous /
Constant Fever –
When Temp. Variation is not more than
2° C in between Morning and Evening Time and does not return normal up to 1
week.
e.g.- UTI, Lobar Pneumonia, Typhoid
(Step Ladder Pattern)
2. Remittent
Fever –
When Temp. variation is more than 2°
in between morning and evening. Temperature does not return to normal up to 1
week.
e.g. Influenza, Brucellosis, Infective
Endocarditis
3. Intermittent
Fever –
When the temperature returns back to
normal at regular intervals.
It is of 3 types –
A. Quotidian-
Fever occurs once in every Second Day
(Periodicity – 24 Hours / 1 Day)
e.g. Plasmodium Knowlesi
B. Tertian –
Fever occurs once in every Third Day
(Periodicity – 48 Hours/ 2 Days)
e.g. P. Ovale (Benign Tertian), P.
Vivax (Benign Tertian), P. Falciparum (Malignant Tertian)
C. Quartan –
Fever occurs once in every Fourth Day
(Periodicy – 72 Hours / 3 Days)
e.g. P. Malarie
4. Inverse Fever
–
Highest Range of Temp. – In Morning
Lowest Range of Temp. – In Evening
e.g. Miliary Tuberculosis (T.B.
Bacteria)
5. Hectic Fever /
Swinging / Septic Fever –
When the temperature variation is very
great (>5°C)
e.g. Septicemia (Infection in Blood)
6. Relapsing
Fever-
A brief febrile period followed by one
or more day Normal Temperature.
(Fever short Time → Normal Temperature
→ Fever → Normal Temperature)
Interval is not regular.
e.g. Borellia Infection
7. Pyrexia of
Unknown Origin (PUO/FUO)-
Illness for at least 3 weeks duration
with body temperature > 38°C and Diagnosis is not established after 1 week
of Hospital Investigation.
8. Rigor-
Sudden Shivering attack followed by
rise in body temperature.
e.g. Malaria
Stages of Rigor -
Cold (Shivering, Cold) → Hot
(Hyperpyrexia, Thirst ↑) → Sweat (Perspiration, Body Temp.↓)
9. Algor Mortis –
Reduction in body temperature after
Death.
Site – Rectal (After Death)
Glaister Equation
Estimation of time of Death (H) = [98.6-
Rectal Temp. (°F)] / 1.5
