Download 07_-_Fever

Fever– A Clinical approach
Dr Sabir
Definition
 an 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 variation
 the 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 Clue
 It is an essential host defense mechanism
 Associated with or without localizing signs
 It can be due to Infection, inflammation or neoplasm
Hyperthermia
 Hyperthermia—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- Patterns
o 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 PUO
1. FEVER – more than 38.3º C
2. At least 3 wk
3. 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 %
DDx
 Infection: amoebic liver abscess, brucellosis, TB,
Typhoid, IE….etc
 Malignancy: soild tumors (pancreas, lung, sarcoma,
colon…etc)
 Systemic dis: SLE, Reiter’s, granulomatous
hepatitis…etc
 Miscellaneous: drug fever, factitious fever,
hyperthyroidism, Behcet’s dis, FMF…etc
Drug fever
 Any drug may be responsible
 Examples: nitrofurantoin, phenytoin, hydralazine,
methyldopa, quinidine, quinine, procainamide
 Very rarely caused by: digoxin, aminoglycosides
 Peripheral eosinophilia is a clue but present only in
25%
FEVER WITH HEPATOSPLENOMEGALY
MALARIA
TYPHOID
LYMPHOMA
LEUKEMIA
DISSEMINATED TB
INFECTIVE ENDOCARDITIS
BRUCELLOSIS
KALA AZAR
HIGH ESR
TB
TEMPORAL ARTERITIS
CARCINOMA
LYMPHOMAS
ABSCESS
MYELOPROLIFERATIVE DISORDER
FEVER & LOW PLATELETS
VIRAL FEVERS
LEUKEMIA
LYMPHOMA
MYELOPROLIFERATIVE DISORDER
DRUG FEVER
SLE
HIV INFECTION
DIAGNOSTIC TESTS
 ANA,ANTI- Ds DNA – SLE
 BONE SCAN- OSTEOMYELITIS, METASTASIS
 ECHO HEART – ATRIAL MYXOMA, IE
 SMEAR TEST + VE – MALARIA,
 VIRAL CULTURE + IN EBV, CMV INFECTIONS
 BLOOD CULTURE + IN IE, SEPSIS
 AGGLUTININ TEST + IN SALMONELLA , BRUCELLOSIS