Fever and hyperthermia

Rationale

Fever is an elevation of body temperature above the normal range for an individual and is induced by cytok ine activation. Fever is often due to infection but can be associated with malignancy, inflammatory disease, or other causes. In contrast, hyperthermia is an elevation in core body temperature due to thermoregulation failure.

Elevated body temperature is a common presentation that can be due to a mild, self-limited illness or to a life-threatening medical emergency.

Causal Conditions

(list not exhaustive)

1. Infections
   1. Bacterial (e.g., group A Streptococcus, Escherichia coli)
   2. Viral (e.g., influenza virus, measles virus)
   3. Parasitic (e.g., Plasmodium)
   4. Fungal (e.g., Cryptococcus)
2. Inflammatory and malignant conditions (e.g., systemic lupus erythematosus, lymphoma)
3. Drugs and toxins (e.g., bleomycin, interferon)
4. Drug-induced syndromes (e.g., neuroleptic malignant syndrome, serotonin syndrome )
5. Increased heat load (e.g., due to exertion in hot environments)
6. Diminished heat dissipation (e.g., due to medication effects or substance use)
7. Factitious presentations

Key Objectives

Given a patient with fever or hyperthermia, the candidate will diagnose the cause, severity, and complications, and initiate appropriate management. In particular, the candidate will rule out life-threatening conditions (e.g., meningococcal meningitis).

Enabling Objectives

Given a patient presenting with fever or hyperthermia, the candidate will

1. list and interpret critical clinical findings, including those derived from
   1. a relevant history that includes
      1. infectious symptoms (e.g., productive cough, dysuria, diarrhea),
      2. travel history (e.g., locations, timing, use of chemoprophylaxis),
      3. host factors (e.g., immunocompromised state due to HIV, previous splenectomy),
      4. noninfectious symptoms (e.g., weight loss, night sweats, arthralgias),
      5. environmental factors (e.g., heat exposure, exertion),
      6. drug therapy (e.g., corticosteroids), and
   2. a relevant physical examination aimed at determining the cause;
2. list critical investigations and interpret the results of the investigations, including
   1. targeted initial investigations if required to determine the cause (e.g., chest radiography, urinalysis, blood cultures, lumbar puncture), and
   2. additional investigations for fever of unknown origin (e.g., bone marrow biopsy, echocardiography, targeted imaging);
3. construct an effective initial management plan based on the presentation, including
   1. initiating measures to reduce body temperature (e.g., acetaminophen, evaporative cooling),
   2. treating the underlying cause (e.g., antimicrobials),
   3. determining whether specialized care is required, including taking measures to protect others (e.g., isolation), and
   4. determining whether further preventive measures, such as immunizations, should be recommended.