Diferencia entre revisiones de «Acute fever»

m (Rossdonaldson1 moved page Fever to Acute fever)
(Add to Category:Symptoms - common EM chief complaint)
 
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==Background==
==Background==
===Definition===
===Definition===
*Defined as [[Celsius Fahrenheit Temperature Conversion|temperature]] ≥38°C (100.4°F)  
*Defined as [[Celsius Fahrenheit Temperature Conversion|temperature]] ≥38°C (100.4°F).
*>41.0°C (105°F) needs urgent treatment (damage neurons)
*Peripheral temperature is not clinically accurate and central measurements are the preferred means of determining fever.
**Rectal or oral
**Rectal temperatures should not be performed in neutropenic patients<ref>Niven DJ, Gaudet JE, Laupland KB, Mrklas KJ, Roberts DJ, Stelfox HT. Accuracy of Peripheral Thermometers for Estimating Temperature: A Systematic Review and Meta-analysis. Ann Intern Med. 2015;163(10):768-777. doi:10.7326/M15-1150.</ref>


==Acute Fever Differential Diagnosis==
==Clinical Features==
{{Template:Acute Fever DDX}}
*Fever directly causes an increase in:<ref>Davies P, Maconochie I. The relationship between body temperature, heart rate and respiratory rate in children. Emerg Med J. 2009 Sep;26(9):641-3. doi: 10.1136/emj.2008.061598.</ref>
**Heart rate: 10 beats per minute per degree centigrade
**Respiratory rate


==DDx by Heart Rate==
==Differential Diagnosis==
Fever 0.55 C increases HR ~10bts/min
{{Acute Fever DDX}}


#Relative bradycardia
===DDx by Heart Rate===
## Concomitant medication
''Every 0.55°C increase in temperature should → increase HR by ~10BPM
## Drug fever
*If patient has relative bradycardia, consider:
## [[Typhoid Fever]]
**Concomitant medication
## Brucellosis
**Drug fever
## [[Leptospirosis]]
**[[Typhoid Fever]]
#Frank bradycardia
**Brucellosis
## [[Rheumatic Fever]]
**[[Leptospirosis]]
## [[Lyme Disease]]
*If patient has frank bradycardia, consider:
## Viral Myocarditis
**[[Rheumatic Fever]]
## [[Endocarditis]]
**[[Lyme Disease]]
**Viral Myocarditis
**[[Endocarditis]]


==Evaluation==
===General Approach===
*History: duration, recent travel, sick contacts, immunocompromised status, medications, recent procedures/hospitalizations, indwelling devices
*Physical exam: systematic search for source — HEENT (sinuses, pharynx, ears, dental), lungs, heart, abdomen, skin/wounds, GU, joints, spine
*Not all fevers require a workup — well-appearing immunocompetent adults with clear viral URI symptoms may need only supportive care
===Workup (when indicated)===
*Basic: CBC with differential, BMP, urinalysis, blood cultures (x2 if concern for bacteremia), CXR
*Additional based on suspicion:
**Lactate, procalcitonin — if sepsis suspected
**[[Lumbar puncture]] — if meningitis/encephalitis suspected
**CT imaging — guided by suspected source (abdomen/pelvis for abdominal source, CT chest for pulmonary, CT head if AMS)
**LFTs, lipase — if hepatobiliary or pancreatic source suspected
**Joint aspiration — if septic arthritis suspected
**Wound cultures — if skin/soft tissue infection
===Special Populations Requiring Lower Threshold for Workup===
*See [[Pediatric fever of uncertain source]] for infants and children
*See [[Neutropenic fever]] for oncology patients
*See [[AIDS fever of unknown origin]] for HIV/AIDS patients
*See [[Fever in traveler]] for returned travelers
*See [[Fever and rash]] for fever with associated rash


==Workup==
==Management==
See individual notes for specific workup:
*Antipyretics:
*[[Fever and Rash]]
**[[Acetaminophen]] 650-1000 mg PO/IV q4-6h (max 4g/day)
*[[Fever of Unknown Origin]]
**[[Ibuprofen]] 400-800 mg PO q6-8h
*[[Neutropenic Fever]]
**Antipyretics improve comfort but do not treat the underlying cause
*[[AIDS Fever of Unknown Origin]]
**Fever itself is generally not harmful in immunocompetent adults (except in [[hyperthermia]] where temperature >41C/106F can cause organ damage)
*[[Heat Emergencies]]
*Treat the underlying condition:
*[[Fever in Traveler]]
**Empiric antibiotics if bacterial infection suspected — do not delay for cultures
**Source control (I&D of abscesses, removal of infected lines/devices)
**See specific disease pages for targeted management
*Fluid resuscitation: Fever increases insensible losses; ensure adequate hydration
*Avoid "fever phobia": In immunocompetent patients, aggressive fever treatment is not required and may mask clinical trends
 
==Disposition==
*Admit:
**Suspected sepsis or bacteremia
**Immunocompromised with fever (neutropenic fever)
**Hemodynamic instability
**Identified source requiring IV antibiotics or surgical intervention
**Unreliable follow-up with concerning clinical picture
*Discharge:
**Well-appearing with clear viral syndrome
**Identified source amenable to outpatient treatment (uncomplicated UTI, mild cellulitis)
**Reliable follow-up with clear return precautions
**Return precautions: worsening symptoms, inability to tolerate PO fluids, rigors, altered mental status


==See Also==
==See Also==
*[[Fever (Peds)]]
*[[Pediatric fever of uncertain source]]
*[[FUO (Peds)]]
*[[Fever and rash]]
*[[Fever and Rash]]
*[[Fever of unknown origin]]
*[[Fever of Unknown Origin]]
*[[Neutropenic fever]]
*[[Neutropenic Fever]]
*[[AIDS fever of unknown origin]]
*[[AIDS Fever of Unknown Origin]]
*[[Environmental heat diagnoses]]
*[[Heat Emergencies]]
*[[Fever in traveler]]
*[[Fever in Traveler]]
 
==External Links==
 
==References==
<references/>


[[Category:Symptoms]]
[[Category:ID]]
[[Category:ID]]

Revisión actual - 09:41 22 mar 2026

Background

Definition

  • Defined as temperature ≥38°C (100.4°F).
  • Peripheral temperature is not clinically accurate and central measurements are the preferred means of determining fever.
    • Rectal or oral
    • Rectal temperatures should not be performed in neutropenic patients[1]

Clinical Features

  • Fever directly causes an increase in:[2]
    • Heart rate: 10 beats per minute per degree centigrade
    • Respiratory rate

Differential Diagnosis

<translate>

Fever

Infectious


Non-infectious

</translate>

DDx by Heart Rate

Every 0.55°C increase in temperature should → increase HR by ~10BPM

Evaluation

General Approach

  • History: duration, recent travel, sick contacts, immunocompromised status, medications, recent procedures/hospitalizations, indwelling devices
  • Physical exam: systematic search for source — HEENT (sinuses, pharynx, ears, dental), lungs, heart, abdomen, skin/wounds, GU, joints, spine
  • Not all fevers require a workup — well-appearing immunocompetent adults with clear viral URI symptoms may need only supportive care

Workup (when indicated)

  • Basic: CBC with differential, BMP, urinalysis, blood cultures (x2 if concern for bacteremia), CXR
  • Additional based on suspicion:
    • Lactate, procalcitonin — if sepsis suspected
    • Lumbar puncture — if meningitis/encephalitis suspected
    • CT imaging — guided by suspected source (abdomen/pelvis for abdominal source, CT chest for pulmonary, CT head if AMS)
    • LFTs, lipase — if hepatobiliary or pancreatic source suspected
    • Joint aspiration — if septic arthritis suspected
    • Wound cultures — if skin/soft tissue infection

Special Populations Requiring Lower Threshold for Workup

Management

  • Antipyretics:
    • Acetaminophen 650-1000 mg PO/IV q4-6h (max 4g/day)
    • Ibuprofen 400-800 mg PO q6-8h
    • Antipyretics improve comfort but do not treat the underlying cause
    • Fever itself is generally not harmful in immunocompetent adults (except in hyperthermia where temperature >41C/106F can cause organ damage)
  • Treat the underlying condition:
    • Empiric antibiotics if bacterial infection suspected — do not delay for cultures
    • Source control (I&D of abscesses, removal of infected lines/devices)
    • See specific disease pages for targeted management
  • Fluid resuscitation: Fever increases insensible losses; ensure adequate hydration
  • Avoid "fever phobia": In immunocompetent patients, aggressive fever treatment is not required and may mask clinical trends

Disposition

  • Admit:
    • Suspected sepsis or bacteremia
    • Immunocompromised with fever (neutropenic fever)
    • Hemodynamic instability
    • Identified source requiring IV antibiotics or surgical intervention
    • Unreliable follow-up with concerning clinical picture
  • Discharge:
    • Well-appearing with clear viral syndrome
    • Identified source amenable to outpatient treatment (uncomplicated UTI, mild cellulitis)
    • Reliable follow-up with clear return precautions
    • Return precautions: worsening symptoms, inability to tolerate PO fluids, rigors, altered mental status

See Also

External Links

References

  1. Niven DJ, Gaudet JE, Laupland KB, Mrklas KJ, Roberts DJ, Stelfox HT. Accuracy of Peripheral Thermometers for Estimating Temperature: A Systematic Review and Meta-analysis. Ann Intern Med. 2015;163(10):768-777. doi:10.7326/M15-1150.
  2. Davies P, Maconochie I. The relationship between body temperature, heart rate and respiratory rate in children. Emerg Med J. 2009 Sep;26(9):641-3. doi: 10.1136/emj.2008.061598.