Persistent fever

Introduction Sustained fever can be caused by a variety of diseases. It is a fever activator acting on the body, which causes the endogenous pyrogen (EP) to be incorporated into the brain to act on the body temperature regulation center, which in turn causes the release of the fever central medium to cause changes in the set point, eventually causing fever and fever. Do not retreat, maintain a relatively smooth high heat or low heat. Persistent fever is mainly divided into infectious fever and non-infectious fever caused by pathogens. When people can't maintain normal body temperature, many physiological functions will be impeded.

Cause

Continuous high fever

(1) Infectious diseases

1 tuberculosis: patients with fever onset have acute hematogenous disseminated tuberculosis, tuberculous meningitis, invasive tuberculosis and other unexplained long-term fever.

2 typhoid paratyphoid: more common in summer and autumn, in case of persistent fever for more than 1 week, should pay attention to the possibility of typhoid.

3 bacterial endocarditis: persistent fever for more than 1 week, accompanied by skin and mucous membrane defects, heart murmur changes splenomegaly, anemia, microscopic hematuria and other blood cultures have pathogenic bacteria growth.

4 bacterial liver abscess: chills and high fever, liver pain, hepatomegaly, tenderness, sputum pain, typical diagnosis is easier.

5 amebic liver abscess: intermittent or persistent fever, liver pain, hepatomegaly, tenderness, weight loss and anemia.

(2) Non-infectious diseases

1 primary liver cancer: general diagnosis is easier. When the fever is the main complaint, it is difficult to diagnose, such as persistent fever or relaxation heat, or irregular low fever, a small number of people with high fever (such as inflammatory or diffuse liver cancer) can be mistaken for liver swelling or infectious diseases.

2 malignant lymphoma: any unexplained lymph node enlargement according to inflammation or tuberculosis treatment for 1 month invalid, unexplained fever, should consider the possibility of this disease, the diagnosis depends mainly on pathology.

3 malignant histiocytosis: fever is a common symptom. The cause of long-term fever is unknown, accompanied by hepatosplenomegaly, and the epidemiological data, symptoms and signs do not support acute infection and hematopoietic dysfunction, the possibility of this disease must be considered.

4 acute leukemia: may have fever, blood smear, bone marrow examination can confirm the diagnosis of atypical leukemia.

5 vascular-connective tissue disease:

(1) Systemic lupus erythematosus: long-term fever accompanied by more than two organ damage blood leukopenia should consider this disease. SLE can always have no typical rash during the course of the disease, only characterized by high fever.

(2) nodular polyarteritis: manifested as long-term fever with myalgia, joint pain, subcutaneous nodules (lower limbs along the vascular line distribution, or into a strip of cord-like), high blood pressure of kidney damage, gastrointestinal symptoms.

(3) rheumatoid arthritis: may have chills, fever, transient rash, joint pain is not obvious, lymphadenopathy, hepatosplenomegaly, iridocyclitis, myocarditis, increased white blood cells, increased erythrocyte sedimentation rate, rheumatoid factor Negative, antinuclear antibodies and lupus cells were negative.

(4) mixed connective tissue disease: more common in women is characterized by lupus erythematosus, hardness disease, dermatomyositis clinical manifestations of less kidney involvement, with fever symptoms.

Continuous low heat

1 tuberculosis: a common cause of low fever, more common pulmonary tuberculosis, low fever and anorexia, should promptly check tuberculosis (smear or TB-PCR) and chest X-ray examination.

2 chronic renal nephritis: a common cause of low fever in female patients. There can be no obvious symptoms, signs or even urine tests without abnormalities, with low heat as the only performance.

3 chronic lesions infection: irregular irregular hypothermia often accompanied by local symptoms and signs, when the lesions cleared, the symptoms disappeared.

4 AIDS (AIDS): manifested as long-term irregular fever, chronic diarrhea more than 1 month, no general weight loss for general antibiotic treatment, unexplained systemic lymphadenopathy, repeated bacterial fungi, protozoal infections, combined with epidemiological data in time HlVP24 shake antigen detection.

5 cytomegalovirus infection: sustainable low fever, similar to infectious mononucleosis, viral hepatitis based on anti-CMVIgM detection diagnosis.

6 hyperthyroidism: early low fever with palpitations, rapid pulse, excessive appetite, weight loss, hand tremor goiter, local murmur. Detection of T3T4, rT3, and the like.

7 malignant tumors: middle-aged and above have unexplained low fever, increased erythrocyte sedimentation rate, should pay attention to tumor examination such as primary liver cancer. Lung cancer, kidney cancer and colon cancer.

8 neurological hypothermia: more common in young women, obvious in summer. Differences in body temperature during the day can be self-healing due to ineffective drug treatment.

9 low fever after infection: after the control of acute bacterial or viral infection, there is still low fever, lack of appetite, etc., and is related to the patient's autonomic dysfunction.

an examination

Laboratory examinations must be summarized and analyzed based on objective data learned from medical history and physical examination, from which several diagnostic possibilities may be proposed, and further consideration should be given to those examinations to confirm the diagnosis. Therefore, continuous fever can be performed blood routine, urine routine, erythrocyte sedimentation rate, blood potassium, sodium, chloride examination, liver function, renal function, CO2 binding force determination, blood culture and drug sensitivity test, blood fat reaction, external fever reaction, blood Smear to find malaria parasites, cerebrospinal fluid routine, biochemical and culture.

Differential diagnosis

Irregular heat: There is no regularity in fever, and the duration is not necessarily. Can be seen in a variety of lung diseases, heart pleurisy.

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.

Excessive heat: body temperature lasts from 39 °C to 40 °C, for several days or weeks, and the 24-hour fluctuation range does not exceed 1 °C. Found in the extreme stage of fever such as pneumococcal pneumonia, typhoid fever, typhus and typhus.

Intermittent heat: alternating between high heat period and no heat period, body temperature fluctuations can reach several degrees, and no heat period (intermittent period) can last for 1 day to several days, repeated attacks. Found in malaria, acute pyelonephritis and so on.

Regression heat: The body temperature suddenly rose to above 39 °C, and then suddenly dropped to a normal level after a few days. The high-heat period and the no-heat period continued to alternate regularly after several days. Seen in the return to heat, Hodgkin's disease, cycle heat and so on.

Wave-like heat: The body temperature gradually rises to 39 ° C or above, and gradually drops to a normal level after a few days, and then gradually increases after several days, so repeated several times. Found in Brucellosis.

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