INFLAMMATION

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• INFLAMMATION

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Cellulitis

• Definition Acute diffuse suppurative
  inflammation.
• Cause Streptococcus haemolyticus. The organism
  produces two enzymes (1) Fibrinolysin
  (streptokinase) Dissolves fibrin. (2)
  Hyaluronidase (spreading factor) Dissolves
  hyaluronic acid of ground substance helping
  spread of bacteria and its toxins.

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• Sites Loose connective tissue as subcutaneous
  tissue, scrotum, orbit and wall of the appendix.
• Characters
• Failure of localization because of absence of
  fibrin.
• Extensive necrosis.
• Pus is thin in consistency and may contain many
  RBCs i.e. sanguinous.
• Complications
• Acute lymphangitis and lymphadenitis.
• Septic thrombophlebitis causing pyaemic
  abscesses.
• Septicaemia.

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II. NON-SUPPURATIVE INFLAMMATION

• 1. Catarrhal Inflammation Mild acute
  inflammation of the mucous membranes of the
  respiratory and GIT characterized by excess mucus
  secretion. e.g. catarrhal rhinitis (common cold),
  bronchitis, ... etc.

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• 2. Membranous Inflammation (Pseudomembranous)
• Severe acute inflammation characterized by the
  formation of a pseudomembrane on the affected
  surface formed of necrotic cells, fibrin threads,
  leucocytes. e.g. diphtheria and bacillary
  dysentery.

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• 3. Fibrinous Inflammation Characterized by an
  exudate rich in fibrinogen e.g. lobar pneumonia.
• 4. Serofibrinous Inflammation It involves
  serous sacs as pleura, peritoneum and
  pericardium. Characterized by excess serous
  exudates in the sac and deposition of fibrin on
  the surface.

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Serofibrinous Inflammation
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• 5. Hemorrhagic InflammationCharacterized by
  cellular exudate rich in the red blood cells due
  to vascular damage e.g. smallpox.

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• 6. Allergic Inflammation
• as urticaria. It is an antigen antibody
  reaction characterized by abundant fluid exudates
  and eosinophils.

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CHRONIC INFLAMMATION
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• Chronic inflammation is characterized by the
  following 1.The irritant is mild and has a
  prolonged action. 2. The tissue response is
  gradual and prolonged. 3. Chronic inflammation
  may follow acute inflammation or starts as slowly
  progressing chronic disease as in tuberculosis
  and syphilis.

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• 4. Histopathologically it shows
• End arteritis obliterans (E.A.O) of small
  arteries.
• Chronic inflammatory cells include lymphocytes,
  plasma cells, macrophages.
• Fibrosis which is the surest sign of chronicity.

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Fibrosis

• E.A.O

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Types of Chronic inflammation

• 1. Chronic non-specific inflammation Different
  irritants produce inflammatory reactions of the
  same non-specific microscopic picture of chronic
  inflammation e.g. chronic non-specific
  cholecystitis.
• 2. Chronic specific inflammation
• Each irritant or organism produces a
  characteristic microscopic picture called
  granuloma e.g. tuberculosis, bilharziasis and
  leprosy

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Granuloma

• Definition
• Chronic specific inflammation forming a tumor
  like mass grossly and characterized
  microscopically by focal accumulation of large
  number of chronic inflammatory cells.

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Pulmonary Tuberculosis
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• Types
• 1. Infective granuloma
• Bacterial as TB, leprosy syphilis
• Parasitic as bilharziasis leishmaniasis
• Mycotic (fungus) as madura foot, actinomycosis
• Viral as granuloma inguinale
• 2. Non-infective granuloma
• As silicosis, asbestosis and foreign-body
  granuloma.
• 3. Unknown cause
• Sarcoidosis, crohns disease

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Histopathology of granuloma

• Macrophages main bulk of granuloma, made of
  tissue histiocytes and blood monocytes.
• Other inflammatory cells as lymphocytes, plasma
  cells, eosinophils.
• Granulation tissue.
• Fibrous tissue.
• Specific organism or foreign body.

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Foreign body granuloma to suture material (nylon,
silk) contains multinucleated giant cells, with
haphazardly arranged nuclei. These giant cells
are fused macrophages. The foreign body is
birefringent, and sometimes may be visible by
polarized light in the middle of the granuloma or
inside the giant cells.
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Schistosomiasis
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