Fever– A Clinical approach

Fever– A Clinical approachDr Sabir

Definitionan oral temperature exceeding 37.2°C in the early

morning and 37.7°C in the late afternoon or evening

(Rectal temperatures are higher by approximately 0.6°C )

Diurnal variationthe mean diurnal temperature oscillation is

approximately 0.5°C, with women generally having slightly higher normal temperatures than men. Temperature is lowest in the early morning and highest in the late afternoon or early evening

The diurnal rhythm is usually preserved with a fever

What is fever ?

FEVER is a Diagnostic ClueIt is an essential host defense mechanismAssociated with or without localizing signs It can be due to Infection, inflammation or neoplasm

HyperthermiaHyperthermia—not mediated by cytokines—occurs

when body metabolic heat production or environmental heat load exceeds normal heat loss capacity or when there is impaired heat loss; heat stroke is an example. Body temperature may rise to levels (> 41.1 °C) capable of producing irreversible protein denaturation and resultant brain damage; no diurnal variation is observed.

Antipyretics are effective in treating fever but are unlikely to affect hyperthermia.

Neuroleptic malignant syndrome is a rare and potentially lethal idiosyncratic reaction to major tranquilizers( haloperidol, fluphenazine)

Treatment: dantrolene ± bromocriptine or levodopa Serotonin syndrome: occurs within hours of ingestion of

agents that increase levels of serotonin in the CNS, including serotonin reuptake inhibitors, monoamine oxidase inhibitors, tricyclic antidepressants, pethidine, dextromethorphan, bromocriptine, tramadol, and lithium.

Treatment: central serotonin receptor antagonist—cyproheptadine or chlorpromazine ± a benzodiazepine.

Fever- Patternso Intermittent type – temp return to normal once during most days

o Remittent type – temp do not return to normal each day

o Sustained/Continuous – temp do not vary more than 1 degree F /day

o Relapsing - recurrent over days to weeks

Fever - types

Classical PUO1. FEVER – more than 38.3º C2. At least 3 wk3. Cause not diagnosed after 3 OP visits or 3 days of

hospitalization.

TYPES OF PUO: ACUTE, NOSOCOMIAL, HIV ASSOCIATED NEUTROPENIC PUO

PUO – causes

INFECTIONS – 40%MALIGNANCY –30%CONNECTIVE TISSUE D- 20 %UNDIAGNOSED – 10 %

DDxInfection: amoebic liver abscess, brucellosis, TB,

Typhoid, IE….etcMalignancy: soild tumors (pancreas, lung, sarcoma,

colon…etc)Systemic dis: SLE, Reiter’s, granulomatous

hepatitis…etcMiscellaneous: drug fever, factitious fever,

hyperthyroidism, Behcet’s dis, FMF…etc

Drug feverAny drug may be responsibleExamples: nitrofurantoin, phenytoin, hydralazine,

methyldopa, quinidine, quinine, procainamideVery rarely caused by: digoxin, aminoglycosidesPeripheral eosinophilia is a clue but present only in

25%

FEVER WITH HEPATOSPLENOMEGALY MALARIATYPHOID LYMPHOMALEUKEMIADISSEMINATED TBINFECTIVE ENDOCARDITISBRUCELLOSISKALA AZAR

HIGH ESR TBTEMPORAL ARTERITISCARCINOMALYMPHOMASABSCESSMYELOPROLIFERATIVE DISORDER

FEVER & LOW PLATELETS

VIRAL FEVERSLEUKEMIALYMPHOMAMYELOPROLIFERATIVE DISORDERDRUG FEVERSLEHIV INFECTION

DIAGNOSTIC TESTS

ANA,ANTI- Ds DNA – SLEBONE SCAN- OSTEOMYELITIS, METASTASISECHO HEART – ATRIAL MYXOMA, IESMEAR TEST + VE – MALARIA,VIRAL CULTURE + IN EBV, CMV INFECTIONSBLOOD CULTURE + IN IE, SEPSISAGGLUTININ TEST + IN SALMONELLA , BRUCELLOSIS