Inflammation 3

• Cellulitis


  Acute diffuse suppurative inflammation

  
• Cellulitis


  • Caused by Streptococcus haemolyticus
  • Organism produces fibrinolysin (streptokinase) which dissolves fibrin
  • Organism produces hyaluronidase (spreading factor) which dissolves hyaluronic acid of ground substance helping spread of bacteria and its toxins
• Cellulitis


  • Occurs in loose connective tissue as subcutaneous tissue, scrotum, orbit and wall of the appendix
  • Failure of localization because of absence of fibrin
  • Extensive necrosis
  • Pus is thin in consistency and may contain many RBCs i.e. sanguinous

  
• Cellulitis


  • Complications: Acute lymphangitis and lymphadenitis, Blood spread: Septicaemia and toxaemia

  
• Catarrhal Inflammation


  Mild acute inflammation of the mucous membranes of the respiratory and GIT characterized by excess mucus secretion
• Catarrhal Inflammation


  • Catarrhal rhinitis (common cold), bronchitis

  
• Membranous Inflammation (Pseudomembranous)


  Severe acute inflammation characterized by the formation of a pseudo membrane on the affected surface formed of necrotic cells, fibrin threads, leucocytes

  
• Membranous Inflammation


  • Diphtheria, bacillary dysentery

  
• Fibrinous Inflammation


  Characterized by an exudate rich in fibrinogen
• Fibrinous Inflammation


  • Lobar pneumonia
• Serous, fibrinous, serofibrinous Inflammation

  Involves skin or serous sacs as pleura, peritoneum and pericardium, Characterized by excess serous exudates in the sac and deposition of fibrin on the surface

  
• Hemorrhagic Inflammation


  Characterized by cellular exudate rich in the red blood cells due to vascular damage

  
• Hemorrhagic Inflammation


  • Smallpox, acute hemorrhagic pancreatitis
• Allergic Inflammation


  Antigen antibody reaction characterized by abundant fluid exudates and eosinophils

  
• Allergic Inflammation


  • Urticaria

  
• Chronic Inflammation


  • Irritant is mild and has a prolonged action
  • Tissue response is gradual and prolonged
  • May follow acute inflammation or start as slowly progressing chronic disease

  
• Chronic Inflammation


  • Histopathologically shows: End arteritis obliterans of small arteries, Chronic inflammatory cells include lymphocytes, plasma cells, macrophages, Fibrosis which is the surest sign of chronicity

  
• Chronic non-specific inflammation


  Different irritants produce inflammatory reactions of the same non-specific microscopic picture

  
• Chronic non-specific inflammation


  • Chronic non-specific cholecystitis

  
• Chronic specific inflammation


  Each irritant or organism produces a characteristic microscopic picture called granuloma

  
• Chronic specific inflammation


  • Tuberculosis, bilharziasis, leprosy
• Granuloma


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


  • Infective granuloma (Bacterial, Parasitic, Mycotic, Viral)
  • Non-infective granuloma (Silicosis, asbestosis, foreign-body)
  • Unknown cause (Sarcoidosis, Crohn's disease)

  
• Histopathology of Granuloma


  • Macrophages main bulk, lymphocytes, plasma cells, eosinophils, granulation tissue, fibrous tissue, specific organism or foreign body
• Microscopic picture


  • Tuberculous granuloma, Foreign body granuloma to suture material