Fever Li Shuang

Definition An elevation of core body temperature above the normal range

Normal temperature Normal temperature 36~37 ℃ Core body temperature varies throughout the day <1 ℃ Fever: Oral>37.3 ℃ Rectal> 37.6 ℃ difference>1.2 ℃

Pathogenesis Anteror hypothalamus thermostat Heat gain effector system Heat loss effector system Organ:skin Organ: skeletal muscle, liver Set-point theory

pathogenesis Endogenous pyrogens Exogenous pyrogens Bacteria,viruses, immune complexes Interleukin,TNF Interferon Fever Hypothalamic set point Disruption of hypo- thalamic thermostat Production of heat↑ Loss of heat↓ Failure of body`s temperature- regulating mechanisms CNS disease Inherited malignant hyperthermia Strenous exercise or other stress Chills Thyrotoxicosis Heat stroke Heart failure Skin conditions

Etiology and classification Infective fever various microorganisms, such as bacteria, virus, mycoplasma, fungus

None-infective fever Absorption of necrotic substances: injury; ischemic necrosis; Endocrine and metabolic disturbances: hyperthyroidism and dehydration Decreased elimination of heat from skin: heat failure Dysfunction of central heat regulation: a: Physical, as heat stroke; b: chemical, as barbiturate poisoning; c: Mechanical, as cerebral hemorrhage. Dysfunction of vegetative nervous system; as the cases of sympathetic overactivity. Etiology and classification

The effects of Fever Enhanced neutrophil migration Increased production of antibacterial substances by neutrophils Increased production of interferon Increased antiviral and antitumor activity of interferon Increased T-cell proliferation Decrased growth of microorganisms in iron-poor environment

Clinical manifestation Grade of fever Hyperthermia fever: over 41 ℃ High fever: 39.1~41 ℃ Moderate fever: 38~39 ℃ Low grade fever: 37.3~38 ℃ 37 ℃ 38 ℃ 39 ℃ 40 ℃ 41 ℃

The clinical course and character of fever Clinical manifestation 37 ℃ onset persistence subsidence

Patterns of Fever Continued Fever Above normal throughout the day Fluctuate less than 1 ℃ in 24 hours Lobar pneumonia, typhoid

Remittent Fever Patterns of Fever Temperature above 39 ℃ Fluctuate more than 2 ℃ in 24 hours Sapraemia, acute infectious endocarditis

Intermittent Fever Patterns of Fever Episodes of fever separated by days of normal temperature Malaria

Undulant Fever Patterns of Fever Increase to 39 ℃ in several days and then slowly return to the normal Brucellosis, tumor

Irregular Fever Patterns of Fever No regular pattern tuberclosis

Caution Using Antibiotic Using antipyretic or glucocorticoid Individual difference. e.g. medically frail elderly people with pneumonia

Associated symptoms Chills or rigor acute infective disease, transfusion reaction Lymph node enlargement infectious mononucleosis, lymphoma, leukemia

Enlargement of liver and spleen infectious mononucleosis. lymphoma. Leukemia.hepatitis Coma cerebritis. Cerebral hemorrhage Associated symptoms

Rash measles. Connective tissue diseases. Drug fever

History taking When, acute or chronic, fever grade, pattern Chilly, sweating Systemic symptoms: respiratory system, digestive system, urinary system General condition Treatment course (antibiotic? antipyretic?)

Diagnostic points Other symptoms besides Fever Duration and magnitude of Fever Close contact with similar illness Occupational, travel, recreational exposure History of disease Current medication Allergy

Case Repeated chill then fever bacteremia Local infection Seek for Infection site History taking and examination

Case 2 Patient with hepatitis Chill and fever leukocytosis Local infection abdominal infection? ultrasonic testing 1st normal 1week, hiccup,position change aggravation diaphragm subphrenic abscess

Summary Definition Pathogeneses Etiology Clinical course Patterns Associated symptoms Diagnosis points

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