Inflammation due to viruses

1. INFLAMMATION

2. CHRONIC INFLAMMATION
 Chronic inflammation is a response of prolonged duration (weeks or months) in
which inflammation, tissue injury, and attempts at repair coexist in varying
combinations.
 Chronic inflammation may occurs by one of the following ways:
 Chronic inflammation following acute inflammation. E.g. acute osteomyelitis progressing
to chronic osteomyelitis, pneumonia terminating in lung abscess.
 Recurrent attacks of acute inflammation. E.g. recurrent urinary tract infection leading to
chronic pyelonephritis, repeated acute infection of the gallbladder leading to chronic
cholecystitis.

3. Major difference between Acute and
Chronic inflammation
FEATURE ACUTE INFLAMMATION CHRONIC INFLAMMATION
1. Response onset
and duration
i) Within short time, fast
ii) Lasts for short duration
i) After delay, slow
ii) Lasts longer
2. Cardinal signs of
inflammation
Invariably present Generally imperceptible
3. Pathogenesis i) Vascular events:
haemodynamic changes,
increased vascular
permeability
ii) Cellular events: exudation of
leucocytes, phagocytosis
iii) Role of chemical mediators
i) Following acute of
inflammation
ii) Recurrent attacks of acute
inflammation
iii) Chronic inflammation
from beginning
iv) Role of chemical
mediators

4. FEATURE ACUTE INFLAMMATION CHRONIC INFLAMMATION
4. Main
inflammatory
cells
i) Neutrophils
ii) Eosinophils
iii) Lymphomononuclear cells
(late)
iv) Pus cells
i) Lymphocytes
ii) Plasma cells
iii) Monocytes/macrophages
(epithelioid cells in
granulomas)
iv) Giant cells(foreign body,
langhans type)
5. Plasma
exudation
Present May or may not be present
6. Systemic effects i) Fever: high grade
ii) Leucocytosis (neutrophilic,
eosinophilic)
iii) Acute phase reactant proteins
iv) Lymphadenitis-lymphangitis
v) Septic shock(in severe acute
infection)
i) Fever: mild
ii) Leucocytosis
(lymphocytic,monocytic)
iii) Lymphadenitis-lymphangitis
iv) Raised ESR
v) Anaemia
vi) Amyloidosis (in long-lasting
cases)

5. FEATURE ACUTE INFLAMMATION CHRONIC INFLAMMATION
7. Main
morphology
i) Abscesses (suppuration)
ii) Ulcers
iii) Through blood (bacteraemia,
septicaemia, pyaemia)
i) Chronic non-specific
inflammation (infectios, others)
ii) Granulomatos inflammation
(tuberculosis, leprosy, syphilis,
actinomycosis, Crohn disease,
foreign bodies etc)
8. Fate i) Resolution
ii) Repair (regeneration
common, fibrous healing
sometimes)
iii) Progression to chronicity
i) Resolution
ii) Repair: fibrous healing more
common; regeneration may
accompany fibrosis
iii) Dystrophic calcification
9. Common
examples
Pyogenic abscess, cellulitis,
bacterial pneumonia, pyaemia
Granulation tissue, granulation
inflammation( tuberculosis, leprosy
etc), chronic osteomyelitis

6. Examples of Diseases with Granulomatous
Inflammation
DISEASE CAUSE TISSUE REACTION
1. Tuberculosis Mycobacterium
tuberculosis
i) Caseating granuloma (tubercle)
ii) Focus of activated macrophages
(epithelioid cells), rimmed by fibroblasts,
lymphocytes, histiocytes, occasional
Langhas giant cells
iii) Central necrosis with amorphous granular
debris
iv) Acid-fast bacilli
2. Leprosy Mycobacterium
leprae
i) Acid-fast bacilli in macrophages
ii) Noncaseating granulomas
3. Syphilis Treponema
pallidum
i) Gumma
ii) Microscopic to grossly visible lesion,
enclosing wall of histiocytes
iii) Plasma cell infiltrate
iv) Central cells are necrotic without loss of
cellular outline

7. DISEASE CAUSE TISSUE REACTION
4. Cat- scratch
disease
Gram-negative bacillus i) Rounded or stellate granuloma
containing central granular
debris and recognizable
neutrophilis
ii) Giant cells uncommon
5. Sarcoidosis Unknown etiology i) Noncaseating granulomas with
abundant activated
macrophages
6. Crohn
disease(infla
mmatory
bowel
disease)
Immune reaction against
intestinal bacteria, possibly self
antigens
i) Occasional noncaseating
granulomas in the wall of the
intestine, with disease chronic
inflammatory infiltrate