Inflammation

German: Entzündung

1 Definition

Inflammation is the local or systemic reaction of a biological system to an interior or exterior stimulus that endangers physiological processes. The function of inflammation is to eliminate the harmful stimulus and establish the preconditions necessary for repair procedures ("healing"). This means that inflammation is a manifestation of an organism's immune reaction.

Inflammation is a complex process which is regulated by immunocompetent cells, antibodies, inflammatory mediators and several other factors.

see also: acute-phase reaction

2 Nomenclature

Inflammation of a specific organ or tissues is usually systematically signalized by the use of the suffix "-itis" after the Greek name of the organ. For example:

• Inflammation of the skin: dermatitis
• Inflammation of the urethra: urethritis
• Inflammation of the myocardium: myocarditis
• Inflammation of the meninges: meningitis

3 Categories

3.1 ... according to the development of the disease

• Acute inflammation
• Subacute inflammation
• Chronic inflammation
  • Primary chronic inflammation
  • Secondary chronic inflammation
• Recurrent inflammation
• Peracute inflammation

3.2 ... according to its spread

• Local inflammation
• Generalized inflammation
• Metastatic inflammation

3.3 ... according to its specificity

• Specific inflammation
• Unspecific inflammation

3.4 ... according to macroscopic aspects

• Serous inflammation
• Fibrous inflammation
• Purulent inflammation
• Hemorrhagic inflammation

3.5 ... according to histological aspects

• Lymphocytic inflammation
• Granulomatous inflammation

4 Symptoms

The five classical local signs of inflammation are (according to Galen):

• Redness ("rubor")
• Swelling ("tumor")
• Pain ("dolor")
• Heat ("calor")
• Loss of function ("functio laesa")

Besides those local signs of inflammation there can occur general reactions of the body, according to the severity of the inflammation. Those general signs include:

• Fever
• Night sweat
• Generally feeling unwell

4.1 Laboratory analysis

Laboratory medicine uses, amongst others, the following parameters to determine inflammatory processes:

• Erythrocyte sedimentation rate (ESR)
• C-reactive protein (CRP)
• Hemogram (leukocyte count)
• Differential blood count
• Procalcitonin (PCT)