FEVER CHEN SHU nfectious disease division Huashan Hospital, Fudan University
FEVER CHEN SHU Infectious Disease Division Huashan Hospital, Fudan University
Fever o Normal body temperature 口37C( set point D Circadian variation oral T 0. 40C> axillary T ● Definition of fever O An elevation of core body temperature above the normal range
Fever Normal body temperature: 37oC (set point) Circadian variation oral T 0. 4oC > axillary T Definition of fever: An elevation of core body temperature above the normal range
Fever(with pyrogens) Pyrogens数热原 Elevated set-point Maintaining an abnormally elevated Temperature BMR(basal metabolic rate) increases BMR个10% =T个0.6°c T个= Elevated set-point
Fever(with pyrogens) Pyrogens 致热原 Elevated set-point Maintaining an abnormally elevated Temperature BMR(basal metabolic rate) increases T = Elevated set-point BMR 10% = T 0.6oC
PATHOGENESIS OF FEVER Antigens HYPOTHALAMUS Antigen antibody T-lymphocyte complex Bacteria and Prostaglandin E bacterial products Lymphokines Endogenous Increase in body pyrogens temperature -k(interleukin 1)-+"set point (Tumor necrosis factor) Viruses (Interferon a) Heat generation Mononuclear Heat conservation phagocyte Crystals (eg. urate) Fever
PATHOGENESIS OF FEVER
EXP Macrophage EnP hypothalamus lymphocyte Heat lossy Fever Set point个 Heat production↑
Set point↑ hypothalamus Heat loss Heat production↑ Fever ExP Macrophage lymphocyte EnP
FEVER Without pyrogens Excessive heat Decreased Loss of production dissipation regulation TA>unchanged set-point
FEVER(without pyrogens) Excessive heat production T > unchanged set-point Decreased dissipation Loss of regulation
ACUTE FEBRILE ILLNESS a always represents a common problem a Acute onset with localizing sumptoms easy to get diagnosis a gradual onset without toxic r---only need follow-up are required a gradual onset with toxic -----hospitalization should be considered
ACUTE FEBRILE ILLNESS always represents a common problem Acute onset with localizing sumptoms -------easy to get diagnosis gradual onset without toxic -----only need follow-up are required gradual onset with toxic ------hospitalization should be considered
FEVER OF UNKNOWN ORIGIN Old definition 1. Fever higher than 383C on several occasions 2. Duration of fever -3 weeks 3. Uncertain diagnosis after one week of study in hospital New Definition D Eliminated the in-hospital evaluation requirements>3 outpatient visits, or 3 days in hospital.. Ambulatory as well as in hospital
FEVER OF UNKNOWN ORIGIN Old Definition: 1. Fever higher than 38.3oC on several occasions. 2. Duration of fever – 3 weeks 3. Uncertain diagnosis after one week of study in hospital New Definition: Eliminated the in-hospital evaluation requirements → 3 outpatient visits, or 3 days in hospital. … Ambulatory as well as in hospital
Epidemiology and etiology Categories of Illness Causing PUo Infections 30-40% Malignancies 20-25% Collagen Vascular disease 25-30% Undiagnosed 10-15%
Epidemiology and Etiology Infections 30 - 40 % Malignancies 20 – 25 % Collagen Vascular Disease 25 – 30 % Undiagnosed 10 – 15 % Categories of Illness Causing PUO
The Age ■ Children→ infection is the most frequent 口EB∨,CMV.. others ■Elde!y→ Neoplasm&CT- Disorders 口 Giant cell arteritis }>50yr(30%) a Polymyalgia Rheumatica y
The Age Children → infection is the most frequent. EBV, CMV… others Elderly → Neoplasm & CT-Disorders Giant cell arteritis } > 50 yr (30%) Polymyalgia Rheumatica }
