Category:Chronic Inflammation

Types

Granulomatous Inflammation

Granulation Tissue

Granulation tissue (Courtesty of BioMed Archive)

• Is completlely different to granulomatous inflammation, despite the similarity in name!
• Occurs on the surface of the skin where large areas of the epithelium have been lost.
• Makes up the lining of sinus tracts discharging from deeper lesions.
• Takes its name from the gross appearance of the small vessels which appear at the surface.
  • Look like red granules.
  • These vessels supply inflammatory cells, mainly neutrophils, to the infected surface.
• The most frequent example in domestic animals is the formation of excessive granulation tissue on the legs of horses with poorly healing wounds.
  • "Proud flesh"
• Ulcers and open wounds may heal by granulation.

Lymphocytic Inflammation

• Lymphocytic inflammation is a diffuse chronic ongoing inflammation.
• Seen in:
  1. Diseases of the central nervous system.
     • Lymphocytes appear microscopically as several layers of cells around blood vessels in the perivascular space.
     • They indicate that there is damage to the nervous tissue further in.
       • Should alert to the possibility of viral infection, which is a common cause of central nervous system disease.
         • E.g. louping ill.
  2. The gut.
     • An excessive number of lymphocytes diffusely infiltrating the lamina propria, often in conjunction with plasma cells, indicate an ongoing non-specific chronic enteritis.
  3. The respiratory tract.
     • Peribronchial and peribronchiolar cuffing may occur to the point of actual lymphoid follicle formation in these areas.
       • Follicles are sometimes large enough to cause partial occlusion of the airways.
     • A feature of some chronic lung diseases.
       • Ee.g. Mycoplasmosis in swine and calves.