Acute Inflammation
Acute Inflammation
Acute Inflammation
ACUTE INFLAMMATION
-
Protein content
Sp Gr
Cellular components
Pus
-
Exudate
High
>1.020
Inflammatory cells, cellular
debris
Transudate
Low (Albumin)
<1.020
None
MORPHOLOGIC PATTERNS
1. Serous
- Plasma-like effusion with no cells
- There is abundant protein-rich fluid exudate with a relatively low cellular content
- Vascular dilatation may be apparent to the naked eye
- Inflammation of the serous cavities, such as peritonitis, and inflammation of a
synovial joint, acute synovitis
- Early inflammation, heart failure, pleural effusions
2. Purulent or Suppurative
- The term suppurative and purulent denote the production of pus
- Contains dying and degenerate neutrophils, proteins, tissue debris, infecting
organisms
- Caused by pyogenic bacteria
- The pus may become walled-off by granulation tissue or fibrous tissue or produce
an abscess (a localized collection of pus in a tissue
- Empyema
Hollow viscus fills with pus (empyema of the gall bladder or the appendix)
3. Fibrinous
- Contains large amounts of fibrinogen
- Forms thick stick meshwork that may cause areas to stick together
- Thick fibrin coating
- Often seen in acute pericarditis giving the parietal and visceral pericardium a bread
and butter appearance
4. Membranous
- Contains fibrinous or fibrinopurulent material with necrotic cells
- Often found in mucous membranes, some microbial infection
5. Serosanguinous
- Contains both serous and hemorrhagic materials
- Caused by bleeding, serous exudation like injury and burns
Exudates in Inflammatory Process
1. Hemorrhagic
- Contains large amount of RBC and other cells
- Damaged or vascular injury or permeable blood vessels or depletion of coagulation
factors
- Acute pancreatitis due to proteolytic destruction of vascular walls, and in
meningococcal septicemia due to disseminated intravascular coagulation
2. Mucinous or Catarrhal
- When mucus hypersecretion accompanies acute inflammation of a mucous
membrane
- Contains large amount of mucous and epithelial cells
- Inflammatory conditions like allergic rhinitis, common
Types of Inflammation According to Location
1. Abscess
- Localized collection of pus in a part of the body, surrounded by an inflamed area
- The area will most likely look like a giant boil or cyst that can become extremely
red and infected
2. Ulcer
- An open sore of the skin, eyes or mucous membrane, often caused by an initial
abrasion and generally maintained by an inflammation and/or an infection
3. Catarrhal
- Mucosal surface
- Thick mucous and WBCs
4. Membranous
- An epithelium becomes coated by fibrin, desquamated epithelial cells and
inflammatory cells
- An example is the grey membrane seen in pharyngitis laryngitis due to
Corynebacterium diphtheriae
5. Pseudomembranous
- Formed by the fibrin and necrotic surface epithelium
- A structure which resembles the luminal surface of tissue (looks like the affected
tissue is covered by a membrane)
Causes
1. Follows an acute inflammation
2. Repeated bouts of acute inflammation
A. Persistent infections of intracellular microbes (tubercle bacilli, viral infections)
B. Prolonged exposure to nondegradable but potentially harmful substances
(silicosis, asbestosis)
C. Immune reactions (autoimmune disease)
Hallmark of Chronic Inflammation:
- Mononuclear cells
Morphology
1. Infiltration of mononuclear cells (macrophages, lymphocytes, plasma cells, mast cells,
eosinophils)
2. Tissue destruction
3. Attempts at healing by CT replacement (angiogenesis and fibrosis)
Granulomatous Inflammation
-
Presence or absence of DM
Presence of absence of immunosuppressive drugs (e.g. glucocorticosteroids)
Adequate levels of circulating, normal functioning WBCs