Infectious fever

Introduction Infectious fever, infection caused by various pathogens (virus, bacteria, mycoplasma, chlamydia, rickettsia, Helicobacter, fungi, parasites, etc.), whether acute or chronic, localized or systemic, Any fever can occur. The pathogenesis is caused by the metabolites of pathogenic microorganisms or their toxins acting on white blood cells and releasing endogenous pyrogens, which have small molecular mass and can directly act on the body temperature regulating center through the blood-brain barrier, so that the body temperature The set point moves up, causing fever.

Cause

Various infectious diseases such as bacteria, viruses, fungi, spirochetes, and malaria parasites act on the body temperature regulation center, body temperature center dysfunction or excessive heat production caused by various causes, and heat dissipation is reduced, resulting in a situation in which the body temperature rises beyond the normal range.

1. Respiratory viral infections.

2. Severe acute respiratory syndrome.

3, hemorrhagic fever with renal syndrome.

4. Infectious mononucleosis.

5, epidemic encephalitis.

6, acute viral hepatitis.

7, typhus.

8, acute focal bacterial infections.

9, sepsis.

an examination

Related inspection

Body temperature measurement tissue factor pathway inhibitor liquid gas chest sign blood donor health check hepatitis E antibody (anti-HEIgM)

Infectious fever tests have the following characteristics:

1. Onset of illness with or without chills.

2, systemic and localized symptoms and signs.

3. Blood: The white blood cell count is higher than 1.2x10 ⁹ /L, or lower than 0.5x10 ⁹ /L.

4, tetrazolium blue test (NBT): such as neutrophil reduction NBT more than 20%, suggesting bacterial infection, help with the identification of viral infection and non-infectious fever (normal value 5C reaction protein determination (CRP ): Positive indicates bacterial infection and rheumatic fever, and negative is mostly viral infection.

5, neutrophil alkaline phosphatase score increased: normal value is 0 ~ 37, the higher the higher the higher the more favorable for the diagnosis of bacterial infection, when the exclusion of pregnancy cancer, malignant lymphoma more meaningful. It can be raised or false positive after application of hormones.

Differential diagnosis

Identification:

Unexplained fever: The concept of generalized unexplained fever refers to all fevers of unknown origin. However, in the clinic, the narrow concept of fever is also adopted, that is, fever of unknown cause. The fever lasted for more than 3 weeks, the body temperature was above 38.5 °C, and the diagnosis was not confirmed by detailed medical history, physical examination and routine laboratory tests.

Central fever: refers to fever caused by abnormalities in the body temperature regulation center caused by central nervous system diseases. The fever caused by systemic or local inflammation should be strictly excluded before diagnosis, and other causes of fever should be excluded. Most cases of intracranial disease with fever are critical cases, most of which are caused by intracranial inflammation, intrapulmonary infection, and urinary tract infection. For the unexplained increase in moderate body temperature, the source of infection or the cause of infection cannot be found at one time, and it cannot be easily considered as central fever. The cause of systemic or local infection should be repeatedly searched for, and attention should be paid to the cause of drug fever and other fevers.

Persistent fever: When the mouth temperature is higher than 37.3 ° C or the anus temperature is higher than 37.6 ° C, the change in one day exceeds 1.2 ° C, which is called fever. According to the level of fever, it can be divided into the following clinical classifications: low heat 37.4 ° C ~ 38 ° C moderate heat 38.1 ° C ~ 39 ° C high heat 39.1 ° C ~ 41 ° C ultra high heat 41 ° C or more, lasting more than 4 weeks, for continuous fever .

Relaxation heat: The body temperature continues to be above 39 degrees, and the fluctuation range is large. The body temperature fluctuation range exceeds 2 degrees within 24 hours, but both are above the normal level.

Non-infectious fever: caused by various infectious diseases, aseptic substances or various inflammatory effects on the body temperature regulation center, body temperature central dysfunction or excessive heat production caused by various causes, reduced heat dissipation, resulting in increased body temperature The normal range of situations. Non-infectious fever has the following characteristics: 1. The heat course is longer than 2 months, and the longer the heat course, the greater the possibility. 2, long-term fever is generally good, no obvious symptoms of poisoning. 3, anemia, painless multi-site lymphadenopathy, hepatosplenomegaly.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.