Acute Fever (DDX)

Definition

• Defined as Temp >37.8 C (100.4 F)
• >41.0 C (105 F) needs urgent Tx (damage neurons)

DDX

Infectious

1. Critical
   1. Sepsis
   2. PNA w/ resp failure
   3. Peritonitis
   4. Meningitis
   5. Cavernous sinus thrombosis
   6. Necrotizing Fasciitis
2. Emergent
   1. PNA
   2. Peritonsillar abscess
   3. Retropharyngeal abscess
   4. Epiglottitis
   5. Endocarditis
   6. Pericarditis
   7. Appendicitis
   8. Cholecystitis
   9. Diverticulitis
   10. Intra-abdominal abscess
   11. Pyelonephritis
   12. Tubo-ovarian abscess
   13. Encephalitis
   14. Brain abscess
   15. Cellulitis
   16. Abscess
   17. Malaria
3. Non-emergent
   1. OM
   2. Sinusitis
   3. Pharyngitis
   4. Influenza
   5. Tb
   6. UTI
   7. Epididymitis
   8. Prostatitis

Non-infectious

1. Critical
   1. AMI
   2. PE
   3. Intracranial hemorrhage
   4. CVA
   5. NMS
   6. Thyroid storm
   7. Acute adrenal insufficiency
   8. Transfusion Rx
   9. Pulmonary edema
   10. Heatstroke
   11. Malignant Hyperthermia
2. Emergent
   1. CHF
   2. Dehydration
   3. Recent Seizure
   4. Sickle cell dz
   5. Transplant rejection
   6. Pancreatitis
   7. DVT
   8. Serotonin Syndrome
3. Non-emergent
   1. Drug fever (except as in NMS, Serotonin syndrome)
   2. Malignancy
   3. Gout
   4. Sarcoidosis
   5. Crohn's dz
   6. Postmyocardiotomy sy

DDx by Heart Rate

Fever 0.55 C increases HR ~10bts/min

1. Relative bradycardia
   1. Concomitant medication
   2. Drug fever
   3. Typhoid
   4. Brucellosis
   5. Leptospirosis
2. Frank bradycardia
   1. Rheumatic fever
   2. Lyme dz
   3. Viral myocarditis
   4. Endocarditis

Source

2/26/06 DONALDSON (adapted from Rosen)