Inflammation

Inflammation
An allergic reaction to cefaclor has led to inflammation of the skin on the foot. The cardinal signs of inflammation include: pain, heat, redness, swelling, and loss of function. Some of these indicators can be seen here.
SpecialtyImmunology, rheumatology
SymptomsHeat, pain, redness, swelling
ComplicationsAsthma, pneumonia, autoimmune diseases
DurationAcute: few days
Chronic: up to many months, or years
CausesInfection, physical injury, autoimmune disorder

Inflammation (from Latin: inflammatio) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants.[1][2] The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin calor, dolor, rubor, tumor, and functio laesa).

Inflammation is a generic response, and therefore is considered a mechanism of innate immunity, whereas adaptive immunity is specific to each pathogen.[3]

Inflammation is a protective response involving immune cells, blood vessels, and molecular mediators. The function of inflammation is to eliminate the initial cause of cell injury, clear out damaged cells and tissues, and initiate tissue repair. Too little inflammation could lead to progressive tissue destruction by the harmful stimulus (e.g. bacteria) and compromise the survival of the organism. However inflammation can also have negative effects.[4] Too much inflammation, in the form of chronic inflammation, is associated with various diseases, such as hay fever, periodontal disease, atherosclerosis, and osteoarthritis.

Inflammation can be classified as acute or chronic. Acute inflammation is the initial response of the body to harmful stimuli, and is achieved by the increased movement of plasma and leukocytes (in particular granulocytes) from the blood into the injured tissues. A series of biochemical events propagates and matures the inflammatory response, involving the local vascular system, the immune system, and various cells in the injured tissue. Prolonged inflammation, known as chronic inflammation, leads to a progressive shift in the type of cells present at the site of inflammation, such as mononuclear cells, and involves simultaneous destruction and healing of the tissue.

Inflammation has also been classified as Type 1 and Type 2 based on the type of cytokines and helper T cells (Th1 and Th2) involved.[5]

  1. ^ Ferrero-Miliani L, Nielsen OH, Andersen PS, Girardin SE (February 2007). "Chronic inflammation: importance of NOD2 and NALP3 in interleukin-1beta generation". Clinical and Experimental Immunology. 147 (2): 227–235. doi:10.1111/j.1365-2249.2006.03261.x. PMC 1810472. PMID 17223962.
  2. ^ Chen L, Deng H, Cui H, Fang J, Zuo Z, Deng J, et al. (January 2018). "Inflammatory responses and inflammation-associated diseases in organs". Oncotarget. 9 (6). Impact Journals, LLC: 7204–7218. doi:10.18632/oncotarget.23208. PMC 5805548. PMID 29467962. S2CID 3571245.
  3. ^ Abbas AB, Lichtman AH (2009). "Ch.2 Innate Immunity". Basic Immunology. Functions and disorders of the immune system (3rd ed.). Saunders/Elsevier. ISBN 978-1-4160-4688-2.
  4. ^ "Inflammation and Your Health". Cedars-Sinai.
  5. ^ Berger A (August 2000). "Th1 and Th2 responses: what are they?". BMJ. 321 (7258): 424. doi:10.1136/bmj.321.7258.424. PMC 27457. PMID 10938051. Archived from the original on 12 July 2021. Retrieved 1 July 2021.