37.5
Pyrexia / Fever: body temp increased 1-4°C. Protective – not fully known*.
- Inflammation is a defence mechanism with local & systemic effects and tissue injury. Also initiate healing process.
- Exogenous Pyrogens: Bacterial products, LPS (lipopolysaccharides)
- Endogenous Pyrogens: IL-1, IL-6, TNF
- Pathogenesis: increased cyclooxygenase → Prostaglandins (PGE2) in Hypothalamus → reset thermal clock → Fever.
- NSAIDs: Inhibit cyclooxygenase in hypothalamus. Only reduce systemic effects and local tissue injury without significantly affecting defence mechanism. (unlike steroids*)
- Defective inflammation (e.g.DM): increase Infections, immunosuppression.
damage to any tissue releases IL-1, IL-6, TNF → fever, pain, swelling vasodilation
Protective effects:
- Brain → PGs → fever
- Liver → Acute phase reactants
- Bone marrow → increased WBC production
Pathological effects