Historia de la Fiebre

Historical Overview of Fever

• Ancient civilizations (6th century BC) documented fever as a sign of illness, associating it with redness and heat.
• Hippocrates (5th century BC) linked fever to an imbalance of bodily humors, specifically the yellow bile.
• Galen (2nd century AD) believed fever arose from a restoration of balance among humors.
• The Middle Ages attributed fever to demonic possession.
• William Harvey (18th century) studied blood circulation in relation to fever.
• Claude Bernard (19th Century) recognized fever as a metabolic response.
• Carl Reinhold Wunderlich (1868) measured body temperature, demonstrating circadian rhythms and disease-specific fevers.

Fever Definition

• Fever is an elevated body temperature, typically a defensive response to invading microorganisms.
• It indicates immune system activity.
• A temperature greater than 37.8°C is considered fever.
• Normal body temperature is around 35-35°C, regulated by the hypothalamus.

Fever Mechanisms

• Microbial products trigger the immune system, activating pyrogenic cytokines (like PGE2).
• Cytokines cross the blood-brain barrier, influencing the hypothalamus.
• The hypothalamus regulates body temperature through mechanisms like shivering (increasing heat production) and vasoconstriction (minimizing heat loss).

Fever Treatment Considerations

• Fever treatment aims to relieve symptoms, not cure the underlying cause.
• Treatment decisions depend on severity and underlying medical conditions.
• Fever in the elderly, those with cardiovascular or respiratory issues, can significantly impact their well-being, so requires close monitoring.
• In some cases, fever might be a positive sign (e.g., indicating a strong immune response to infection), while in others it could signify a severe or potentially life-threatening illness.

Types of Fever

• Fever presentations are classified based on temperature curve patterns (e.g., intermittent, constant, remitting, recurrent).
• Patterns are helpful in diagnostic considerations.
• Fever duration (e.g., less than a week, several weeks) aid in differential diagnosis.

Fever Causes

• Fever has multiple causes, ranging from infections, tumors, autoimmune diseases, and side effects of medications.
• Assessing a patient with fever involves thoroughly exploring their medical history.
• Infectious causes should be prioritized in diagnosis.

Diagnosing Fever of Unknown Origin

• Fever of unknown origin (FUO) describes cases where the cause of fever remains unidentified in a patient despite investigation for a week or more.
• Differential diagnoses for FUO include various infectious and non-infectious diseases.
• Diagnostic strategies include thorough patient history, physical exam, blood tests, lab testing for specific infectious agents, imaging scans, and biopsies for more severe concerns.
• Determining the underlying cause of FUO is crucial for appropriate treatment and management of the patient.

Fever and Sepsis

• Sepsis is a life-threatening condition resulting from a severe body reaction to an infection (a serious infection spreads outside of the original site).
• The condition can cause organ damage and even death, if not acted upon promptly.
• Early diagnosis and treatment are vital for managing sepsis patients.

Fever in Specific Populations (e.g., Children, Elderly)

• Infants and children may have different fever presentations and require specific monitoring and treatment approaches.
• Elderly patients might exhibit atypical symptoms or have other underlying medical problems influenced by fever.

Fever and Medications

• Certain medications can cause fever as a side effect.
• This is crucial when considering underlying causes of fever.