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37°C( set point D Circadian variation oral t0.40C>aⅫ illary T ● Definition of fever D 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 lymphocyte complex Bacteria and Prostaglandin E bacterial products m Endogenous Increase in body pyrogens temperature -(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 e hypothalamus lymphocyte Heat lossy Fever Set point↑ Heat production个
Set point hypothalamus Heat loss Heat production Fever ExP Macrophage lymphocyte EnP
FEVER Without pyrogens) Excessive heat Decreased Loss of production dissipation requlation T>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 Acute onset with localizing symptoms easy to get diagnosis a gradual onset without toxic ---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 ■O| d 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: 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 ■lder!y→ Neoplasm&CT- Disorders 口 Giant cell arteritis }>50y(30%) a Polymyalgia Rheumatica 1
The Age ◼ Children → infection is the most frequent. EBV, CMV… others ◼ Elderly → Neoplasm & CT-Disorders Giant cell arteritis } > 50 yr (30%) Polymyalgia Rheumatica }