Pathology 🩺 Flashcards
What are the upper respiratory tract infections?
(1) Common cold (Acute coryza)
(2) Rhinoscleroma
(3) Diphtheria
What is the Pathology of common cold?
- Acute catarrhal “Inflammation of the mucous membrane” inflammation caused by rhinovirus with few neutrophils.
What is the fate of common cold?
- Subsides after few days with regeneration of the damaged epithelium.
- Secondary bacterial infection — suppurative inflammation (increase number of neutrophils). “سائل أخضر أو أصفر”
- Spread of infection to:
a) middle ear (otitis media).
b) lower respiratory tract (bronchitis, bronchopneumonia). - Chronicity especially in maxillary sinus “Due to congestion with fluid” (due to upward direction of drainage — easy for secretion to retain).
What is the Pathology of rhinoscleroma “Chronic inflammation” ?
- destructive infective granuloma caused by Klebsiella Rhinoscleromatis.
What is the primary site of rhinoscleroma?
Nose
What are the characteristics of rhinoscleroma?
- The primary site is the nose:
✓ enlarged and hard.
✓ Its mucous membrane is thickened and granular —progresses to a hard large mass filling the nasal cavity. - Inflammation may extend to paranasal sinuses, nasopharynx, oropharynx, larynx and trachea.
- It destructs the soft tissue but bony structures limit its spread.
What is the M/E of Rhinoscleroma?
l. Surface epithelium shows areas of hyperplasia or
squamous metaplasia. “To survive”
- Subepithelial tissue shows:
❖Mickulicz cells (hydropic degeneration of macrophages). They are large rounded cells having well definedborders, abundant clear or foamy cytoplasm. The nucleus is small flattened, deeply stained and eccentric.
❖Russel bodies (hyaline change of plasma cells). These are ovoid or rounded eosinophilic bodies, sometimes having pyknotic eccentric nuclei.
❖Granulation tissue & fibrosis.
What is the fate and complications of rhinoscleroma?
- Nasal obstruction.
- Nasal deformity.
- Spread of inflammation to paranasal sinuses, nasopharynx, oropharynx, larynx and trachea.
- Epistaxis. “Rupture of vessels”
- Squamous cell carcinoma (on top of squamous metaplasia). “Pre-cancerous”
What is the definition of diphtheria?
- It is an acute infectious disease caused by corynebacterium diphtheriae, occurs in non- immunized children between 2-5 years of age but may occur in adult. via blood
What is the method of infection by diphtheria?
droplet infection.
What is the pathology of diphtheria?
Via exotoxin:
- Locally: pseudomembranous inflammation.
- Reach distant organs via blood leading to degeneration of parenchymatous organs.
- The draining cervical lymph nodes show lymphoid hyperplasia.
What are the complications of diphtheria?
- Respiratory system — Epistaxis “Like rhinoscleroma” & Aspiration bronchopneumonia. “Due to a transport of part of pseudomembranous inflammation”
- Parenchymatous organs — degeneration (Cloudy swelling, fatty change) and necrosis.
- C.V.S.—Acute heart failure. “Due to acute myocarditis”
- Nervous system — Temporary nerve paralysis & Peripheral neuritis.
What are the infections of the lower respiratory tract?
Pneumonitis
Lobar pneumonia
Bronchopneumonia
What is the definition of pneumonitis?
It is the inflammation of lung
What are the causes of pneumonitis?
“Bacteria, atypical pneumonitis, granuloma and loffler’s pneumonia”
1) Bacterial:
✓ Lobar pneumonia.
✓ Bronchopneumonia.
2) Primary Atypical Pneumonitis:
It is an acute interstitial inflammation confined to alveolar
septa without intra-alveolar exudate. Caused by:
✓ Viruses: as influenza, parainfluenza, measles chicken pox and small pox. “Don’t put Me IN the BOX I can’t breathe!”
✓ Mycoplasma pneumonia.
✓ Undefined agent.
3) Loeffler’s Pnueumonia:
It is pneumonia with eosinophilia. It is due to parasitic infestations e.g. ascaris, ankylostoma and Bilharziasis (verminous pneumonia). “ask uncle bill”
4) Granuloma:
as T.B., sarcoidosis, leprosy, actinomycosis, moniliasis. “
What is the definition of lobar pneumonia?
- Acute bacterial infection involving at least an entire lobe of lung.
What are the causes of lobar pneumonia?
strept. pneumoniae in 95 % of cases. “Dangerous”
What is the method of infection of lobar pneumonia?
By inhalation (droplet infection). “Like diphtheria”
What is the pathogenesis of lobar pneumonia?
A. Pneumococci are inhaled to reach alveoli.
B. In alveoli, it produces an inflammatory reaction with excess fluid exudate.
C. This fluid exudate pass from one alveolus to another through inter- alveolar pores to involve the whole lobe and the bacteria reach the pleura.
D. The fluid together with the cellular exudate expel air away from the alveoli producing a firm airless lobe leading to consolidation (hepatization) of the affected lobe.
What is the type of inflammation caused by lobar pneumonia?
Sero-fibrinous
What are the stages of Sero-fibrinous inflammation of the Lung by lobar pneumonia?
Stage of congestion
Stage of red hepatization
Stage of gray hepatization
Stage of resolution
What is the duration of congestion, red hepatization, gray hepatization and resolution respectively?
1st day
2nd - 4th day
5th - 8th day
9th day till 21
What is the N/E of congestion, red hepatization, gray hepatization respectively?
Enlarged
Red “VD”
Wet sponge
Exudes frothy fluid “some air”
Enlarged
Red
Consolidated (Hepatized)
Dry, Red “air expelled”
S.F Pleurisy Enlarged
Enlarged
Gray
Consolidated (Hepatized)
Dry, Gray “increased fibrin”
S.F Pleurisy
Enlarged
What is the M/E of congestion, red hepatization, gray hepatization respectively?
Congested
Thickened
-Bacteria.
-Fluid exudate
Congested
Thickened
-Bacteria
-Fibrin
-RBCs
-Few neutrophils
Less congested
Thinned & compressed by the distended alveolar spaces
-Dead bacteria
-Shrunken fibrin
-Hemolyzed RBCs
-Numerous PMNL
-Macrophages