When fever is not under control even after 3- or 4-day rest, then one should not neglect that fever. It requires a proper clinical examination, and also based on the symptomatology, a set of blood tests has to be performed, starting from a simple total and differential leucocyte count, a blood smear for malaria, and a urine examination to detect any pus cells. The leucocyte counts straightaway divide the fevers into two groups, (i) those in which there is polymorph nuclear leucocytosis as in pneumonia, septic infections, etc., (ii) those in which the count is normal or low as in typhoid fever and common virus infections. And while making the differential count, one should also look for the malarial parasite. If leukaemia or infectious mononucleosis is the cause of the fever, this will also be revealed by the count. Other laboratory investigations should be made if necessary, according to the dictates of the differential diagnosis.
For giving a basic knowledge on simple blood tests to the readers that a total leukocyte count (TLC) measures the overall number of white blood cells (leukocytes) in a blood sample. A differential leukocyte count (DLC), or white blood cell differential, provides the percentage and absolute number of each type of white blood cell. These tests are crucial for assessing immune system health and diagnosing various conditions, including infections, inflammation, and blood disorders. Total Leukocyte Count (TLC): Normal Range: Typically, 4,000 to 11,000 cells per microliter for adults. Abnormal Results: Leucocytosis (high WBC count): Can indicate infection, inflammation, or certain blood disorders. Leukopenia (low WBC count): Can indicate bone marrow disorders, certain infections, or immune system issues. Next differential leukocyte count (DLC): Normal Ranges (approximate percentages) neutrophils: (55-70%), lymphocytes: (20-40%), monocytes: (2-8%), eosinophils: (1-4%), basophils: (0.5-1%). Interpretation of the results of the blood tests, changes in the percentages of specific white blood cell types, can indicate different types of infections or inflammatory conditions. For example, elevated neutrophils may suggest bacterial infection. Elevated lymphocytes may suggest viral infection. Elevated eosinophils may suggest allergic reactions or parasitic infections. Like this, various blood tests help doctors to make a diagnosis of a variety of conditions and also help to monitor treatment effectiveness.
In summary, the TLC and DLC provide complementary information about the immune system. The TLC gives a general overview of white blood cell numbers, while the DLC provides a more detailed look at the specific types of white blood cells present. Together, these tests are valuable tools for diagnosing and managing a wide range of health conditions.
Sometimes we come across a very high fever, typically defined as a body temperature above 106.7°F (41.5°C), which is called hyperpyrexia.
Hyperpyrexia
Hyperpyrexia is a medical emergency that happens when the body temperature is higher than 106.7 degrees Fahrenheit. Hyperpyrexia is life-threatening if untreated or not treated immediately. In other words, hyperpyrexia is an emergency and requires immediate medical attention. The expected temperature of an adult human is 98.6°F. The temperature for a healthy person can range from 97.8 F to 99.1 F. This range is the desired temperature. It’s known as the “hypothalamic set point.” When there is hyperpyrexia, part of the brain changes the thermostat’s set point to increase the body temperature. How does the hypothalamus affect hyperpyrexia? The hypothalamus is an organ in the brain that regulates temperature. When hyperpyrexia sets in, the hypothalamus increases the body temperature above what’s expected. The hyperpyrexia can be called “hypothalamic fever.” This is because the part of the brain that manages the temperature isn’t working correctly.
What is the difference between hyperpyrexia vs. a fever, vs. hyperthermia? Hyperpyrexia is a body temperature above 106.7°F. A fever is a body temperature above 100.4 F. The hypothalamus increases the body temperature during a fever to fight off an illness or an infection. Hyperthermia is a body temperature higher than 99 or 100°F. It happens when the body absorbs more heat than it can release. It doesn’t affect the temperature set point. Also, hypothermia is the opposite of hyperthermia, when the body temperature drops below 95°F.
Hyperpyrexia symptoms
The main symptom of hyperpyrexia is a body temperature higher than 106.7 degrees F. A high body temperature can make a person dizzy or lightheaded, flushed or pale, nauseated, sweaty, thirsty, tired, or weak. Further when the temperature stays high, there can be severe symptoms like confusion, dehydration, and fast heart rate, loss of consciousness, seizures, Stiff muscles, or muscle cramps.
Causes of hyperpyrexia
An increase in the body’s expected temperature (hypothalamic set point) causes hyperpyrexia. The temperature increase can sometimes happen due to a brain haemorrhage. A negative reaction to anaesthesia or some medication or antipsychotic drugs or a tumour, use of addictive substances, an overactive thyroid (thyroid storm), brain trauma,a or severe bacterial or viral infections like sepsis or COVID-19 can also cause hyperpyrexia.
Complications of hyperpyrexia
Patients present initially with sweating, nausea, muscle cramps, and dizziness, followed in the severe cases by high-grade fever, shock, and coma, with high mortality. Sepsis, coagulopathy, and renal failure are also complications. The diagnosis and the management of hyperpyrexia and other unusual fevers will be discussed in the next issue. (To be concluded)
