Introduction to Inflammation

Definition:

Inflammation is a local response (reaction) of living vascularized tissues to endogenous and exogenous stimuli.  The term is derived from the Latin "inflammare" meaning to burn. Inflammation is fundamentally destined to localize and eliminate the causative agent and to limit tissue injury. 

Thus, inflammation is a physiologic (protective) response to injury, an observation made by Sir John Hunter in 1794 concluded: “inflammation is itself not to be considered as a disease but as a salutary operation consequent either to some violence or to some diseases”.

Causes:

  Causes of inflammation are apparently causes of diseases such as 

 -  physical agents  - mechanical injuries, alteration in temperatures and pressure, radiation injuries.

-  chemical agents-  including  the ever increasing lists of drugs and toxins.

-  biologic agents (infectious)- bacteria,viruses,fungi, parasites

-  immunologic disorders- hypersensitivity reactions, autoimmunity, immunodeficiency states etc

-  genetic/metabolic disorders- examples gout, diabetes mellitus etc…

Nomenclature: 

-  The nomenclatures of inflammatory lesion are usually indicated by the suffix 'itis'. Thus, inflammation of the appendix is called appendicitis and that of meninges as meningitis, etc.… However, like any rule, it has its own exceptions examples pneumonia, typhoid fever, etc….

 Classification:

 Inflammation is classified crudely based on duration of the lesion and histologic appearances into acute and chronic inflammation.

References

Bezabeh ,M. ; Tesfaye,A.; Ergicho, B.; Erke, M.; Mengistu, S. and Bedane,A.; Desta, A.(2004). General Pathology. Jimma University, Gondar University Haramaya University, Dedub University.