Cardinal Signs of Inflammation
Introduction
Inflammation is a protective response of living tissue to injury, infection, or irritation. Its
main purpose is to eliminate the initial cause of cell injury, remove necrotic cells, and
initiate tissue repair.
The classical (cardinal) signs of inflammation were first described by Aulus Cornelius
Celsus, who identified four signs. Later, Rudolf Virchow added the fifth sign.
1. Rubor (Redness)
Definition: Redness of the affected area.
Mechanism:
Due to vasodilation of arterioles.
Increased blood flow (hyperemia) to the injured area.
Mediators involved: Histamine, Nitric Oxide.
Example: Redness around a cut or insect bite.
2. Calor (Heat)
Definition: Increased temperature at the site of inflammation.
Introduction
Inflammation is a protective response of living tissue to injury, infection, or irritation. Its
main purpose is to eliminate the initial cause of cell injury, remove necrotic cells, and
initiate tissue repair.
The classical (cardinal) signs of inflammation were first described by Aulus Cornelius
Celsus, who identified four signs. Later, Rudolf Virchow added the fifth sign.
1. Rubor (Redness)
Definition: Redness of the affected area.
Mechanism:
Due to vasodilation of arterioles.
Increased blood flow (hyperemia) to the injured area.
Mediators involved: Histamine, Nitric Oxide.
Example: Redness around a cut or insect bite.
2. Calor (Heat)
Definition: Increased temperature at the site of inflammation.
