Seminar 1 - Pneumonia Flashcards
(319 cards)
1
Q
Describe the pathogenesis of HSV1 encephalitis
A
Virus enters brain – via trigeminal nerve or reactivation in brain itself
Virus PAMPs recognised by TOL receptors of innate immune cells
Inflammatory response triggered leading to necrosis and apoptosis of viral cells and brain cells
Leads to swelling, oedema and raised ICP
2
Q
Describe the structure of a foreign body granuloma
A
Foreign materials found in the center of the granuloma
Sometimes found within giant cells
There will be epithelioid cells & giant cells on the surface of the foreign body
3
Q
Describe the pathogenesis of a cerebral abscess
A
Bacteria enter the brain
Recognized by TOL receptors on astrocytes and microglia
Initiate the inflammatory response compromising the BBB and bringing peripheral inflammatory cells to the site causing massive inflammation and abscess formation
Fibroblasts from the vessel walls in the granulation tissue then contribute to the capsule formation
4
Q
Describe the difference between gram positive and gram negative
A
Gram positive organisms have a thick peptoglycan layer and single phospholipid bilayer in cell wall
Gram negatives have 2 phospholipid bilayers and a thin peptoglycan layer in their cell wall
Gram positive will stain purple (as thick layer can retain dye) whereas gram negative stains pink (dye is washed out)
5
Q
How do viruses infect a cell
A
They bind to receptors on host cells and enters them where they use the cell to replicate their own DNA
Products can trigger cell death
6
Q
Name the 4 main types of acute inflammation
A
Serous inflammation
Fibrinous inflammation
Purulent inflammation and abscesses
Ulcers
7
Q
What is primary TB
A
When disease occurs in previously unexposed individual
8
Q
What are club cells
A
Cells found in cuboidal epithelium in the respiratory system that have roles in immune modulation, surfactant production, and detoxification
They are secretory and non-ciliated
9
Q
What are the signs of constrictive pericarditis
A
Muffled heart sounds,
Raised JVP
Oedema (incl. hepato and splenomegaly)
10
Q
What is the purpose of granuloma formation
A
It is a cellular attempt to contain an offending agent that is difficult for the body to get rid of
11
Q
Which type of inflammation is more likely to lead to scarring - acute or chronic
A
Chronic
12
Q
How do you diagnose pericarditis
A
Blood tests (FBC, U&E cardiac enzymes)
Appropriate test for underlying cause
Echo (effusion) or CXR (cardiomegaly)
13
Q
How does tissue necrosis cause inflammation
A
Dying cells release molecules which stimulate the inflammatory response
This includes uric acid from DNA breakdown and ATP from the mitochondria
Picked up by receptors on other cells - signal of cell damage
Inflammation will occur regardless of the cause of cell death (trauma, ischaemia etc.)
14
Q
What structures are considered part of the upper respiratory tract
A
all of the structures above the vocal folds: nasal cavity, paranasal sinuses and the pharynx (split into naso- oro- and laryngo-)
Sometimes includes the larynx
15
Q
What cell types are found in the alveoli
A
Type 1 alveolar cells cover 95% of the surface and are simple squamous epithelium, providing a permeable barrier for gases
Type 2 alveolar cells produce surfactant and are involved in alveolar repair since they can proliferate and give rise to type I alveolar cells
Also find resident alveolar macrophages which digest particles which have been missed by the mucous lining of the airway.
16
Q
What is the definition of transmissibility
A
How easily pathogens are spread i.e. the proportion of persons exposed to a pathogen who are infected by it
17
Q
What are the 2 main types of granuloma
A
Foreign body granulomas
Immune granuloma
18
Q
What is the definition of a pathogen
A
A microorganism (or virus) that causes disease
19
Q
How do you diagnose streptococcal toxic shock syndrome
A
No specific test
Diagnosis is made if organ failure and low blood pressure is found in a patient with a group A strep infection
20
Q
What causes a cerebral abscess
A
Usually bacterial infection
Common organisms: strep and staph
21
Q
Describe the epidemiology of cerebral abscesses
A
More common in developing countries Men Vs Women almost 3:1 Most at risk groups: Men< 30 Children aged 4-7 Neonates PWIDs Immunocompromised
22
Q
How do infections spread locally
A
By releasing toxins or enzymes they can move through tissues by causing damage
23
Q
What are the microscopic features of an empyema
A
A a high neutrophil count and large numbers of other leukocytes.
24
Q
What is meningitis
A
Inflammation/ infection of all 3 layers of the meninges surrounding the brain
25
How can we distinguish between strep throat (bacterial) and viral causes of URTI
The following symptoms suggest a virus is the cause of the illness instead of strep throat: cough, runny nose, hoarseness and conjunctivitis
26
What is the definition of infection
The invasion and multiplication of pathogens in the body causing damage to tissues/ triggering an immune response
27
What are the macroscopic features of meningitis
Dense exudate covering the surface of the brain - worse in some areas
Prominent engorged blood vessels protruding from surface
28
What cancers affect the larynx
Most commonly squamous cell carcinoma
Less commonly adenocarcinoma
Affects the supraglottis most commonly
29
How much fluid is normally found in the pleural space
Normally there is less than 15ml in the space to lubricate the surfaces
30
Describe the appearance of lobar pneumonia
Confluent consolidation involving entire lung lobe.
31
When is complete resolution most likely to occur
When the injury is limited or short lived
When the damaged cells are able to regenerate due to limited tissue destruction
Also depends on that particular tissues capacity for regeneration
e.g. Liver can, heart and brain cannot
32
What are the symptoms of adherence mediastinopericarditis
```
Systolic indrawing of diaphragm
Pulsus paradoxus (systolic drops by at least 10mmHg on inspiration)
```
33
What is chronic inflammation
A response of prolonged duration (weeks or months) in which inflammation, tissue injury, and attempts at repair coexist in varying combinations
In response to persistent stimuli or those that are hard to destroy
34
What are the two main subtypes of chronic pericarditos
Adherence mediastinopericarditis and constrictive pericarditis
35
What is the definition of a virus
A core of nucleic acid surrounded by a protein shell that can only reproduce in a living cell
Not classed as a microorganism
36
What causes fibrinous/serofibrinous pericarditis
Acute MI, trauma, cardiac surgery, uraemia and cancer.
37
What causes serous pericarditis
Mainly caused by non-infectious inflammatory disease (rheum fever, SLE, scleroderma)
Infections in nearby tissue (if they cause enough irritation)
Viral infections in other areas of the body (URTI, lung) can sometimes lead onto it
Tumours if they invade the pericardium or nearby lymph nodes
38
How do you diagnose an empyema
Signs of effusion on CXR
Yellow and turbid fluid on aspiration
Presents as exudate on analysis with high neutrophil count
39
How does a cerebral abscess cause death
Raises ICP which affects perfusion or causes herniation
| This damages the respiratory and cardiac centers in the brainstem
40
Describe adherence mediastinopericarditis
Fibrotic adhesions attach the heart to surrounding structures in the mediastinum.
The heart works harder as each contraction is pulling against new resistance - can lead to cardiac hypertrophy and dilation
41
Describe the histology of the pleura
The pleura are a serous membrane formed of simple squamous cells also called the mesothelium
This layer faces into the pleural space
Underneath is a supporting layer of connective and elastic tissues
42
How long does it take a cerebral abscess to form
Takes about 2 weeks from point of infection
| Symptoms may start to arise at any point during abscess formation
43
Define drug resistant TB
Classed as resistance to rifampicin and isoniazid with or without any other resistance.
Requires a regime of at least 6 anti-TB drugs to which the mycobacterium is likely to be sensitive.
44
Describe the structure and histology of the bronchioles
<1mm diameter
No cartilage or glands but some goblet cells
Epithelium decreases in height from columnar to cuboidal as it descends the respiratory tree to the smallest bronchiole
45
What are the symptoms of an empyema
Usually begins as a pneumonia or another infection (and their symptoms)
Then develops a recurring fever
46
What is the definition of a commensal
An organism that lives in or on, and benefits from, another organism
The host receives no benefit but is not harmed.
May be part of body's normal flora
47
What are the common pathogens that enter via the skin
Epidermal injury – Staph aureus, Strep pyogenes
Needles – HIV, Hep C
Bites – malaria, rabies, Lyme’s disease
Superficial infections – dermatophytes (fungi)
48
Which cell types are involved in an immune granuloma
Activated Th1 cells produce cytokines like interferon gamma which activated macrophages
Some parasitic infections can trigger a Th2 response and eosinophils
49
How do leukocytes reach the site of injury
They enter the tissues through the gaps in endothelial cells
Mediated by adhesion molecules and chemokines
Margination - move to the outside of lumen due to stasis
They roll along the endothelium and then bind to integrins
Move across the wall and then follow the chemical signals to the site of damage where they become active
They are key to eliminating the inflammatory trigger
50
What is the definition of a bacteria
A unicellular microorganism that has an organised nucleus and usually a cell wall but lacks organelles
Some have the ability to cause disease
51
What are the risk factors for streptococcal toxic shock syndrome
Age 65+
These with chronic illness (diabetes, alcohol use)
Breaks in the skin (recent surgery etc.)
52
What is vertical transmission
From mother to foetus or newborn
Mother infected in pregnancy can pass it on to growing foetus which may cause defects
Babies can pick up infections when passing through the birth canal such as chlamydia
Some pathogens can be passed through breast milk (HIV, Hep B)
53
What are the terminal bronchioles
The final and smallest bronchioles not involved in gas exchange (end of conducting zone)
Beyond this are the respiratory bronchioles
54
Describe fibrinous inflammation
Occurs when there is greater vascular permeability (as fibrinogen is a large molecule) or when there is a pro-coagulant stimuli (e.g. cancer)
Commonly seen in inflammation of the linings of body cavities (e.g. pericardium)
Fibrin is formed and deposited in extracellular space and can form mesh-like structures
Then either dissolved by fibrinolysis and cleared by macrophages or it develops into scarring
55
What causes haemorrhagic pericarditis
The most common cause is metastases to the pericardial space.
Other causes include cardiac surgery, infection, underlying bleeding disorders or TB.
56
How is the innate immune system activated in sepsis
Infection causes release of pro-inflammatory cytokines and other inflammatory mediators
Activation of the complement system to signpost the infection site and upregulates the immune response
57
What are the main types of meningitis
Bacterial - most common
Viral
Chronic
Non-infectious
58
Describe the histology of the oropharynx
Non-keratinized stratified squamous epithelium
| It is different from the rest of the URT as it has to transmit both air and swallowed food
59
Which individuals are at higher risk of HAP
Those with severe underlying disease, immunosuppression, prolonged antibiotic therapy, or invasive access devices, e.g. intravascular catheters.
Mechanical ventilation is particualrly high risk
60
What is the definition of virulence
The pathogenic ability of a microbe ( their ability to cause disease)
Used a measure of severity
61
Describe the pathogenesis of TB
M. tuberculosis uses host receptors to enter host macrophages via phagocytosis
The bacteria replicates within alveolar macrophages and prevents itself being killed
Its proliferation within macrophages and air spaces results in a bacteremia and multiple seeding sites Most still asymptomatic at this stage
Around 3 weeks post-infection, a TH1-mediated response is initiated and leads to granulomatous inflammation
62
What are the 3 main outcomes of inflammation
Complete resolution
Healing by connective tissue replacement/ scarring
Progression to chronic inflammation
63
What infections usually affect the larynx
Laryngitis is the main disease and can be an isolated infection but is more commonly a feature of generalized URTI
H.influenza can lead to laryngoepiglottitis
Croup - laryngotracheobronchitis
64
Define a transudate
Fluid is low in protein (pleural:serum ratio < 0.5)
Pleural LDH: serum LDH <0.6
Low specific gravity
No cells present
65
List the 5 R's of inflammation
Recognition of the offending agent/stimulus by receptors on inflammatory cells
Recruitment of leukocytes and plasma proteins into the tissues
Removal of the stimulus by phagocytosis
Regulation of the response
Repair (regeneration and/or scarring)
66
What are zoonotic illnesses
Those which spread from animals to humans via bites or consumption of animal products
67
How would a CSF sample appear in viral meningitis
Not purulent
Lymphocytes present
Moderate protein elevation
Normal glucose content
68
What are the risk factors for cerebral abscesses
Immunocompromise
Bacterial endocarditis
Bronchiectasis
69
What are the microscopic features of meningitis
Subarachnoid space filled with neutrophilic exudate
| Also has enlarged blood vessels
70
Describe caseous pericarditis
This subtype is commonly seen in TB patients.
There will be focal regions of caseation in the pericardium.
Presents very similarly to purulent/suppurative
71
What are the symptoms and signs of a pleural effusion
May be asymptomatic
Shortness or breath and pleuritic pain
Stony/dull percussion, reduced chest expansion, vocal resonance and air entry on affected side
Trachea may deviate away from affected side if severe
72
Mycoplasma pneumoniae causes pneumonia in which population groups
Children and young adults
| Often get local epidemics (schools etc)
73
What organisms are common cause of lung abscesses
Staphylococci, streptococci, numerous gram-neg species, and anaerobes are implicated.
Mixed infections are common due to aspiration being a common cause
74
What are the main causative organisms in aspiration pneumonia
A mixed picture of anaerobic oral flora and aerobic bacteria
Oral: bacteroides, prevotella, fusobacterium, pepto-streptococcus.
Aerobes: Strep. Pneumonia, staph. Aureus, h. influenzae, pseudomonas aeruginosa.
75
What are the 4 main routes of infection into the CNS
Haematogenous - most common
Direct implantation - usually after trauma or surgery, may be due to malformations that allow access
Local extension - sinuses, teeth, skull or vertebrae are the most commo
Along peripheral nerves (for viruses like zoster)
76
Describe the pathological appearance of a secondary TB infection
Usually affects the lung apices
Florid cavitation occurs - tissue damage more extensive
Initial lesion in secondary infection tends to be small, well-circumscribed, firm, grey-white to yellow in colour and with variable degrees of caseation and fibrosis
77
Describe an ulcer
A local defect/excavation of the surface of an organ or tissue that is produced by the sloughing (shedding) of inflamed necrotic tissue
Occur only when tissue necrosis & resultant inflammation exist on/near a surface
78
What are the common symptoms and signs of pericarditis
Sharp, central pleuritic pain, may be better on leaning forward, worse on inspiration or lying flat
Fever
Pericardial rub
Saddle shaped ST elevation on ECG
May have congestive symptoms if there's an effusion (SOB etc.)
79
What is the definition of incubation period
The time between exposure to a pathogen and the development of symptoms
80
How does fibrinous/serofibrinous pericarditis present
Classic pericarditis symptoms
If there is a significant volume of fluid the rub may be diminished
Microscopically the fluid is made up of serous fluid and fibrinous exudate
81
What are the 2 main complications of chronic inflammation
Abscess
| Granuloma
82
What are the symptoms of peritonsillar or retropharyngeal abscesses
Severe pain
Difficulty swallowing
Breathing difficulty - if it obstructs the airway
83
What is granulomatous inflammation
A form of chronic inflammation characterized by collections of activated macrophages, often with T lymphocytes (sometimes associated with necrosis)
84
Describe the epidemiology of TB
Leading cause of death worldwide from a single infectious agent (above HIV/AIDS)
Highest incidence in South-East Asia
85
What is the benefit of granulomatous inflammation in TB
In most, this response will halt the infection response to avoid significant tissue destruction
More likely to progress to caseous necrosis in the elderly and immunosuppressed (particularly HIV+)
86
What are the pathological features of TB
Granulomatous inflammation – accumulation & aggregation of activated macrophages (“epithelioid” cells), some may fuse to form giant cells
Caseating granulomas are characteristic - central necrosis is surrounded by lymphocytes and activated macrophages
The combination of granulomatous lesions in the lung parenchyma + lymph nodes = Ghon complex
87
Define hospital acquired pneumonia
Defined as pulmonary infections acquired >48hrs after hospital admission
88
Which pathogens are the most common cause of bacterial meningitis
```
Strep pneumonia,
Neisseria meningitides
E.coli
Group B strep
Listeria monocytogenes
```
89
What is the role of macrophages in chronic inflammation
They are the dominant cell type
They secrete cytokines and growth factors to activate other cells such as lymphocytes - stimulate inflammatory response
hey also ingest harmful pathogens and cellular debris and also initiate repair
90
How does streptococcal toxic shock syndrome present
Begins with fever and chills, muscle aches, nausea and vomiting
24-48 hours later the blood pressure drops and symptoms develop: tachycardia, tachypnea and other signs of organ failure e.g. bleeding/ bruising, jaundice
91
What are some of the complications of treating a cerebral abscess
```
Mainly complications of the craniotomy
Blood clot needing further surgery
Brain swelling
CSF leak
Movement of the skull cap
Infection
Seizure
Stroke
Nerve damage
Loss of mental function
```
92
What is complete resolution
When the site is returned to normal once the inflammatory reaction is complete
93
Why are women more susceptible to infections of the urinary tract
They have a much shorter urethra so pathogens don't have to travel as far
94
How does post-streptococcal glomerulonephritis occur
Strep products can lead to formation of immune complexes that get deposited in the kidneys
Not a strep infection in the kidneys! It is the immune response and complexes which cause it
Produces a local inflammatory reaction in the kidney which leads to injury
95
What organisms commonly cause meningitis in the immunocomprimised
Listeria, TB, Klebsiella, cryptococcus neoformans, anerobics
96
How do neutrophils and macrophages aid the inflammatory response
They can ingest and destroy the pathogens
| Macrophages also produce growth factors to aid repair
97
What is a cerebral abscess
A thin walled, discrete collection of suppurative material within the brain parenchyma often with inflammation surrounding it.
98
In young people pericarditis often occurs alongside which other condition
Myocarditis
99
Describe the histology of the nasal cavity
Vestibule (initial part) = keratinised stratified squamous epithelium
As you move deeper into cavity, the keratin is lost and eventually becomes respiratory epithelium
There is specialized olfactory epithelium found in the roof of the nose to allow smell
100
What are the 3 main types of nasopharyngeal cancer
Keratinising squamous cell carcinoma (worst prognosis)
Non-keratinising carcinoma (undifferentiated) and non-keratinising carcinoma (differentiated)
Basaloid squamous cell carcinoma
101
What are the systemic features of a secondary TB infection
Low grade fever
Night sweats
Weight loss
Pleuritic pain if it extends into pleura
102
How do you treat a pleural effusion
Slow and controlled drainage- through appropriate pleural space
Pleurodesis with talc if recurrent - sticks layers together to obliterate space, prevents fluid accumulating
Surgery if there is recurrent collections and thickening of the pleura
103
Describe constrictive pericarditis
A dense fibrotic scar surrounds the heart.
This restricts the heart’s movement and therefore function
Hypertrophy is not possible as the heart is encased
Cardiac output may be reduced but also cant increase in response to normal systemic needs
104
What organisms commonly cause meningitis in the elderly
Strep pneumo > listeria
105
Describe how vasodilation occurs in the inflammatory process
Mediators of inflammation such as histamine act on the smooth muscle to induce dilation
106
How do Miliary TB and TB meningitis occur
Haematogenous spread of a primary TB infection
| Rare occurrence
107
What are the potential outcomes of an empyema
Can resolve but more commonly organisation occurs and it leaves a dense fibrous adhesion
This will affect lung expansion
108
What is the purpose of inflammation
It is a protective mechanism
It rids the body of the initial cause of cell injury (microbes, toxins etc.)
It also rids the host of the consequences of such injury like necrotic cells and tissues
109
What are the common pathogens that infect the upper respiratory tract
Rhinovirus
Adenoviruses
Influenza viruses
110
How do you determine whether fluid is a exudate or transudate
Aspiration and analysis of the sample
| Further cytology and cellular counts can indicate underlying cause - e.g. Find malignant cells
111
What are the major complication of a strep throat infection
Peritonsillar or retropharyngeal abscesses
Rheumatic fever
Glomerulonephritis
Toxic shock syndrome.
112
How does meningitis cause death
Viral tends not to be fatal
Bacterial can cause raised ICP and herniation
Can also cause sepsis and subsequent septic shock
113
What happens when group A strep infects the URT
It causes acute pharyngitis and tonsillitis otherwise known as “strep throat”
Infections can range from minor, self-limiting illnesses to severely debilitating, deadly diseases
114
What happens when the endothelium becomes activated due to sepsis
Loosened endothelial junctions mean that proteins can pass through
Vessels become ‘leaky’ leading to widespread interstitial oedema
115
What are the clinical features of HSV1 encephalitis
```
Fever
Malaise
Headache
Nausea
Altered mental state- confusion, memory problems
Seizures
Focal neurological deficits
Personality changes
Reduced consciousness, coma and stupor
```
116
Which part of the brain is most commonly affected by HSV1 encephalitis
Temporal lobe
117
What are the 4 main causes of inflammation
Infections
Tissue necrosis
Foreign bodies
Immune reactions
118
How does breaching the epithelial surface allow infection
Breaks in the physical epithelial barrier can allow pathogens to enter the body
Any form of injury (needles, bites, cuts) can allow pathogens in
119
What are the most common sites for ulcer formation
Mucosa of mouth, stomach, intestines or genitourinary tract
| Skin & subcutaneous tissue of the lower extremities in those with vascular insufficiency (diabetes)
120
When does streptococcal toxic shock syndrome occur
Occur when the strep get into the bloodstream (across mucus membranes)
121
Name the recesses formed by the pleura
Costodiaphragmatic and costomediastinal recesses
| These are clinically relevant as this is where fluid will collect
122
What is the definition of colonization
The presence of bacteria on a body surface which is not causing disease in the host
123
How do foreign bodies cause inflammation
Presence alone may cause inflammation - identified as non-self antigens
The trauma caused by them entering the body can be the cause or this can introduce microbes
Some substances produced by the body itself can lead to inflammation if the are deposited in large amounts in tissue (e.g. Urate crystals in gout)
124
What is the definition of a saprophyte
An organism that grows and feeds on dead or decaying organic material.
A lot of fungi come under this group too
125
Describe the pathological appearance of a lung abscess
May be single or multiple and vary in size
Will have a suppurative central destruction of lung tissue within the central area of cavitation
Central cavity may be filled with pus or air
If chronic they will be surrounded by a reactive fibrotic wall
126
How do infections cause inflammation
Different pathogens will elicit the immune response through different means such as toxins, host response etc
Reaction can be mild to severe
127
How does purulent/suppurative pericarditis present
Classic symptoms + symptoms of systemic infection
Macroscopic findings include: reddened and granular serous surfaces with exudate covering it and the exudate which ranges from cloudy serosal fluid to frank pus.
128
Define an exudate
Fluid is high in protein content (pleural:serum ratio > 0.5)
Contains cells from the blood
Pleural LDH: serum LDH >0.6 or more than 2/3 of normal upper limit for serum
129
When does healing by connective tissue replacement/ scarring occur
After substantial tissue destruction
When the tissues involved in the injury are incapable of regeneration
When there is abundant fibrin exudation that cannot be adequately cleared
Common in the body cavities (pleura etc.)
130
What is the most common cause of purulent inflammation
Infection with a pyogenic bacteria
This is a bacteria that causes liquefactive tissue necrosis
One example is staphylococci
131
What is chronic pericarditis
This when there is organisation of the inflammation (scar formation)
This leads to fibrous thickening of the serosal membrane or even thin adhesions.
This doesn’t always impact heart function but can effectively destroy the pericardial space or restrict heart movement
132
What is the definition of a fungi
A large and varied group of eukaryotes that are either parasitic or saprophytic
Some can act as pathogens in humans.
They produce spores and feed on organic matter
Includes molds and yeast
133
What is the common symptom of pleuritis
Pleuritic pain is common as that tissues are inflamed
134
What are the usual defenses of the respiratory system
Large microorganisms are trapped in the mucocilliary system and sent to GI tract
Smaller ones are phagocytosed by macrophages in the alveoli
135
What are the risk factors for nasopharyngeal cancer
Being of south Chinese or north African descent
A diet very high in salt-cured meats and fish
Exposure to EBV
Regular exposure to hardwood dust
Family history
Exposure to HPV virus
About 3 times as many men as women are affected
136
What are the main causes of URTI
Almost always viruses (rhinovirus, coronavirus, adenovirus, influenza)
Bacteria is rare - around 15% of acute pharyngitis only (strep throat)
137
Chlamydia psittaci causes pneumonia in which population groups
Bird owners (typically parrots)
138
How do viruses reach the meninges
Infected with the virus and then it enters the blood, travels across the BBB to infect the brain
139
What are the risk factors for laryngeal carcinomas
Smoking - biggest
Regular drinking large amounts of alcohol
Family history of head/neck cancer
Unhealthy diet
Exposure to certain chemicals and substances, such as asbestos and coal dust
140
How do you treat a peritonsillar or retropharyngeal abscesses
May need to be drained by an ENT specialist
| Can improve on their own
141
What causes a foreign body granuloma
Inert foreign bodies that are too large or complex to be broken down (e.g. fibers, talc, sutures)
They induce inflammation in the absence of T cell-mediated immune response
142
How do you treat nasopharyngeal cancer
External beam radiotherapy, sometimes supplemented with chemotherapy
Surgery doesn't have a major role unless for biopsy, radiation resistant tumours or local recurrence
143
What is the main feature of purulent inflammation
Production of pus - an exudate consisting of high number of neutrophils, debris from dead cells and oedema fluid
144
What are the features of an acutely inflamed ulcer
Polymorphonuclear infiltration
| Vascular dilation in margins of defect
145
Strep pneumonia causes pneumonia in which population groups
Commonest cause of CAP so affects all ages
| Especially in elderly, immunocompromised, alcoholics and those with HF or existing lung disease
146
What are the symptoms of rheumatic fever
Migratory polyarthritis
Fever
Symptoms of heart failure (chest pain, SOB, tachycardia)
Chorea
147
What organisms commonly cause meningitis in infants
E coli
Group B strep
Listeria
148
How does healing by connective tissue replacement/ scarring occur
As it says on the tin
Connective tissue grows in the area of inflammation (organisation)
Granulation tissue fills the site of injury
It is progressively replaced by collagen which is called fibrosis - scar
149
What is secondary TB
When disease occurs in previously exposed host
| The infection can reactivate and cause TB if host immunity declines (risk is around 5-10%)
150
How do infections spread through the lymphatic system
Can either access directly or carried in immune cells (macrophages or lymphocytes)
From lymph nodes, pathogens can access the bloodstream
151
What is the definition of infectious period
The time in which a host can spread the disease and infect others
152
Describe the histology of the bronchus
```
Lined by respiratory epithelium
Has ring of smooth muscle under lamina
propria
Has adipose tissue & submucosal glands in submucosa.
Irregular cartilage plates are found
```
153
How do you treat an empyema
Drainage and treat the underlying cause
154
What is an empyema
Purulent pleural exudate
They form when bacteria spreads into the pleural space
Forms localised areas of yellow/green pus that usually becomes walled off by fibrosis
155
How do bacteria reach the meninges
Skull fracture, head surgery, cribiform plate fracture
Spread from a local infection ie sinusitis
Haematogenous spread from another infection site
Haematogenous spread from nasopharyngeal colonisation
156
What are the macroscopic features of laryngeal carcinomas
In most cases they are obvious following inspection of the larynx with a laryngoscope
Surface is usually smooth, white or reddened with focal thickenings
May have keratosis or ulcerated regions
157
How does sexual transmission lead to infection
Prolonged and unprotected mucosal contact
Microtrauma allows entry to bloodstream
Passed via bodily fluids
Can be systemic or affect reproductive tract
158
Describe the appearance of bronchopneumonia
Patchy exudative consolidative with focal areas of acute suppurative inflammation
Can be confined to one lobe but tend to be bilateral and basal due to the tendency of secretions to gravitate to the lower lobes
159
How long do symptoms of an URTI typically last
7-10 days (can persist up to 3 weeks)
160
How do you treat constrictive pericarditis
Surgical resection of the constricting tissue (pericardiotomy)
161
What are the macroscopic features of encephalitis
Temporal/frontal necrosis
| Haemorrhage
162
Staph aureus causes pneumonia in which population groups
Often complicates viral illness.
| Young, elderly, PWID, underlying disease (e.g. leukaemia, lymphoma, CF).
163
Which patients are at risk of aspiration pneumonia
Reduced consciousness – alcoholism, drug overdose, general anaesthesia, seizure.
Oesophageal conditions – dysphagia, GORD
Neurologic disorders – MS, dementia
Mechanical conditions – NG tube, endotracheal intubation, GI endoscopy, other feeding tubes.
Protracted vomiting
General debilitation
Poor dental hygiene.
164
What proportion of primary TB infection are progressive
Only 5%
Will resemble a bacterial pneumonia (lobar consolidation and pleural effusions)
Caseous necrosis occurs - usually around a granuloma and reginal lymph node
This area becomes known as a ghon focus
165
What are some of the long term complications of a cerebral abscess
Seizures
Loss of mental acuity
Focal neurological deficits
166
Describe how a fibrinous exudate can form a scar
Fibrin is deposited
If not removed it will stimulate the ingrowth of fibroblasts and blood vessels
This forms the scar
167
What causes purulent/suppurative pericarditis
An active infection that invades the pericardium.
| Can be direct invasion, lymphatic, haematogenous or seeded during surgery
168
How does an empyema form
Via bacterial seeding into the pleural space
| This most commonly occurs through direct spread from the lungs but can be lymphatic or haematogenous
169
Describe the mechanisms of increased vascular permeability in inflammation
Gaps in between endothelial cells can open (cells retract)
This is caused by histamine
Endothelial injury - can lead to necrosis and detachment
This can be due to either physical damage or the action of microbes or inflammatory cells
170
What are the physiological defenses of the nasopharynx
Nasal hairs, ciliated epithelia and IgA
171
What is the most common complication of aspiration pneumonia
Lung abscess is often seen in surviving patients
172
What conditions are more likely to lead to bronchopneumonia
COPD, cardiac failure (elderly), complication of viral infection, aspiration of gastric contents
173
How does serous pericarditis present
Microscopic features: large number of lymphocytes and may have neoplastic cells if cancer is the cause.
Mild inflammatory infiltration of the epicardial fat
Presents with classic symptoms
174
What are the 4 main signs of inflammation
```
Redness - caused by vasodilation
Heat - caused by vasodilation
Pain - pressure or surrounding nerves
Oedema - caused by accumulation of exudate
Loss of function
```
Minor symptoms that occur with almost every
175
What are the microscopic features of encephalitis
Cowdry A intranuclear viral inclusions
| Perivascular inflammatory cells
176
What are the risk factors for TB reactivation
```
New infection (<2y)
Organ transplantation
Immunosuppression,
Silicosis
Illicit drug use
Malnutrition
High-risk setting (homeless shelter, prison)
Low socio-economic status
Haemodialysis
```
177
What are the clinical features of a lung abscess
```
Swinging fever
Cough, haemoptysis
Purulent, foul-smelling sputum
Pleuritic chest pain
Malaise, weight loss
Check for finger/toe clubbing, anaemia, crepitations
Empyema develops in 20-30%
```
178
How do you diagnose meningitis
Bloods (culture, FBC, U&E, creatinine, electrolytes, LFTs, clotting, procalcitonin, meningococcal and pneumococcal PCR, serology, glucose )
Throat swab for bacterial culture
CSF sample for microscopy and PCR
179
How does fluid move through the pleura
It moves through this layer due to pressure gradients
| It is drained primarily by the lymph system
180
Describe the anatomy of the pleura
- The pleura are the continuous membranes that surround each lung
They are divided into visceral pleura (in direct contact with lung tissue) and parietal pleura (in contact with the body wall)
The parietal pleura are further divided into 4 sections based on the area they are in contact with.
These are: cervical, costal, diaphragmatic and mediastinal
181
What are the main causes of chronic inflammation
It may occur on its own or follow acute inflammation
Persistent infection - some bacteria are more likely to cause chronic
Hypersensitivity or autoimmune diseases
Prolonged exposure to toxic agents
182
H. influenza causes pneumonia in which population groups
Common cause in adults, especially with COPD
In children it causes life-threatening LRTI and meningitis
183
Moraxella catarrhalis causes pneumonia in which population groups
Elderly
184
What are the risk factors for URTI
Smoking
Conditions such as asthma or allergic rhinitis,
Close contact with children
Poor hygiene
Immunocompromised state
Anatomical abnormalities - polyps, removed tonsils
185
When does acute inflammation progress to chronic
When the acute inflammation cannot be resolved
May be due to persistence of stimuli or interference with normal process of healing (remaining infection, diabetes, poor perfusion etc.)
186
What cell types are found in a granuloma
Strong activation of T lymphocytes leading to macrophage activation
Macrophages can develop abundant cytoplasm and begin to resemble epithelial cells and are called epithelioid cells
Some fuse and become multinucleated giant cells
187
Describe the appearance of Miliary TB
Widespread seeding of TB
| Foci are 2mm in diameter on average, yellow/white in colour, well-circumscribed and firm.
188
What is encephalitis
Infection of the brain that’s within the brain parenchyma itself
May have an associated meningitis
189
Define the term exudation
Used to describe the movement of fluid and cells from the vascular system to the body cavity or tissue
190
How does a transudate form
- It is basically plasma that is forced into the tissues due to an imbalance in the hydrostatic or osmotic pressure in the vessels
If hydro is too high (e.g. heart failure and excess fluid) or is osmo is too low e.g. (decreased protein as seen in liver or kidney diseases)
191
Describe the microscopic appearance of a cerebral abscess
Purulent exudate full of neutrophils
192
How do you treat rheumatic fever
Antibiotics (to treat group A strep)
| Painkillers and steroids if pain is severe
193
What are the symptoms of strep throat
A sore throat that can start very quickly
Pain while swallowing
Fever
Inflamed tonsils (sometimes with white patches or streaks of pus, petechiae on the soft or hard palate)
Enlarged lymph nodes in front of the neck
Children can sometimes experience nausea and vomiting, headaches and stomach pain
May also develop a rash known as scarlet fever
194
How can inhalation allow infection
A huge number of microorganisms are inhaled each day
If they can bypass the usual defenses they can infect the respiratory tract
Pathogens are spread via respiratory droplets (larger and travel shorter distances) or as airborne particles (suspended in air)
Most respiratory infections are droplets
195
Is pus an exudate or transudate
Exudate
| Because it it contains many cell types - neutrophils and debris
196
What type of inflammation can lead to abscess formation
Purulent -
Abscesses are localised collections of pus, produced by seeding by pyogenic bacteria into a tissue
Can indicate chronic inflammation
197
How do you treat streptococcal toxic shock syndrome occur
Treated as a medical emergency - urgent hospital treatment
| IV antibiotics
198
Describe acute inflammation
Quick and self-limiting reaction
Usually in response to pathogens that the body can eliminate quickly such as bacteria
Will have exudation of fluid and proteins (oedema) and leukocytes will move into the area (mainly neutrophils)
Damage is usually repaired once the reaction is complete
199
What causes encephalitis
Mainly viral - most commonly HSV1
Also CMV, rabies
Can be fungal in immunocompromised patients - e.g. acanthomeba
200
Which conditions predispose you to CAP
Extremes of age
Chronic disease (e.g. COPD)
Immune deficiencies
Hyposplenism.
201
How do you treat post-streptococcal glomerulonephritis
Diuretics to increase urine flow
Limit salt/water to treat oedema
Manage hypertension
202
What are the 3 main components of acute inflammation
Vasodilation
Increased permeability of vessels
Emigration of leukocytes
203
How can physical contact allow infection
○ Through skin shedding (sharing towels)
204
Describe the pathogenies of constrictive pericarditis
May develop after acute pericarditis
| However, can occur without a history of acute pericarditis
205
What conditions are more likely to lead to lobar pneumonia
Usually community-acquired and in otherwise healthy young adults.
206
What infections most commonly affect the nose
Main organisms are adenoviruses, echoviruses and rhinoviruses Inflammatory conditions such as the common cold (infective rhinitis) are the most common disease
207
What are the common symptoms of URTI
Cough, sore throat, runny nose, nasal congestion, headache, low grade fever, facial pressure, sneezing, malaise, myalgia
208
What are the clinical features of meningitis
Signs of background infection plus signs of meningeal irritation
Headache, photophobia, neck stiffness, aches, fever, vomiting confusion and irritability
Classic non-blanching rash seen in meningococcal infection
209
What organisms commonly cause meningitis in adults
Strep pneumo > Neisseria meningitides
210
Describe how rheumatic fever develops
Usually develops 1-5 weeks after strep throat
| Thought to be caused by an immune response which leads to a generalized, multisystem inflammatory response
211
What are the common causative organisms for HAP
Most commonly gram negative rods (enterobacteriaceae & pseudomonas sp.) or gram positive cocci (mainly staph. Aureus).
Also: pseudomonas, Klebsiella, Bacteroides, and clostridia
212
Accumulation of serous fluid in the body cavities is given what name
Effusion
| e.g. pleural effusion
213
What are some of the potential complications of rheumatic fever
Risk of reactivation
| Murmurs and arrhythmias
214
What is respiratory epithelium
Pseudostratified ciliated columnar epithelium with goblet cells
It covers the majority of respiratory tract, except the initial part of the nasal cavity and the true vocal cords
215
Describe the structure of an abscess
They have a central liquified region made of necrotic leukocytes and tissue cells
Usually a zone of preserved neutrophils around this necrotic focus
On the outside there may be vascular dilation and parenchymal and fibroblastic proliferation
May become walled off and ultimately replaced by connective tissue.
216
How do you treat pericarditis
NSAIDs (gastric protection)
Add colchicine 500mcg OD or BD for 3 months to prevent recurrence
Treat underlying cause
217
Give an example of a condition that leads to fibrinous inflammation
Following pericarditis
Fibrinous exudate develops within pericardial sac
This can be converted to scar tissue which leads to fibrous thickening of the pericardium
If extensive it can destroy the pericardial space
218
What are the most common causes of pleuritis
Majority of cases arise due to inflammation of the associated lung tissue such as TB, pneumonia, abscesses or infarctions
Other causes include immunological disorders (such as RA or SLE), systemic infection , metastatic cancer affecting the pleura and radiotherapy to the lung or mediastinum
219
Give an example of a condition leading to serous inflammation
Skin blister following a burn or viral infection
Serous fluid accumulates within the damaged epidermis
The epidermis and dermis are separated by the effusion
220
Can a tissue still function if a scar forms after inflammation
Although pathological the tissue is usually still able to function
The scar provides structural stability
However, certain disease are the results of excess fibrosis (IPF or cirrhosis)
221
What are the main symptoms of nasopharyngeal cancer
```
A lump in the neck
Unilateral hearing loss
Tinnitus
Blocked nose
Nose bleeds
Often not present until the cancer is advanced
```
222
Describe the aetiology of lung abscesses
Can be due to aspiration of infective material (common in right lung)
Occur secondary to bacterial infection - higher risk if immunosuppressed
Obstructive tumours can lead to abscess
Infection can spread from adjacent organs or haematogenous spread of pyogenic organisms
223
How long does it usually take symptoms of a URTI to begin
Onset of symptoms: 1-3 days post exposure
224
What are the common pathogens that infect the GI tract
Norovirus and rotavirus
Virbrio cholerae, giardia, shigella, salmonella, H pylori
C diff in antibiotic use
225
Klebsiella pneumoniae causes pneumonia in which population groups
Debilitated and malnourished individuals
| Elderly, diabetics, esp. chronic alcoholics
226
What is the purpose of increased permeability in inflammation
It allows plasma proteins & leukocytes to leave the circulation and reach the site of damage
227
Describe the epidemiology of pneumonia
It is the leading cause of death of children worldwide (highest rates in Sub-Saharan Africa and South East Asia)
Undernutrition, air pollution, second-hand smoke and HIV+ all contribute to pneumonia deaths
228
Why does the inflammatory response need to be regulated
If the reaction continues once the pathogen is eliminated the body can be overwhelmed by the inflammatory response
It will end up causing more damage to tissues
229
What organisms commonly cause meningitis in adolescents
Neisseria meningitides
230
Pneumocystis jirovecii causes pneumonia in which population groups
Immunosuppressed
Specifically in HIV+ patients
(CD4 count of around <200)
231
What infections usually affect the nasopharynx
○ Pharyngitis and Tonsillitis
Often accompany URTI
Rhino, adeno and echo are most common causes but influenzas and RSV can also cause
232
What are the clinical features of bacterial pneumonia
High fever, rigors, productive cough occasionally with haemoptysis.
Pleural involvement – friction rub + pleuritic chest pain.
Correct antibiotic administration significantly improves condition.
233
What is the definition of inflammation
A response of vascularized tissues that delivers leukocytes and molecules of host defense from the circulation to the sites of infection and cell damage in order to eliminate the offending agents
234
How do you diagnose constrictive pericarditis
CXR - small heart and calcification
| CT if need to make sure not restrictive cardiomyopathy
235
What is pleuritis/pleurisy
Pleuritis is the inflammatory form of a pleural effusion
| Can be serous, serofibrinous or fibrinous but all are inflammatory in origin
236
What are the complications of a lung abscess
```
Extension into pleural cavity
Haemorrhage
Septic embolization
Development of brain abscess or meningitis
Rarely - secondary amyloidosis
```
237
Describe the pathogenesis of meningitis
When the pathogen reaches the meninges it triggers the inflammatory response
Tissue damage, swelling and oedema
238
How do you treat laryngeal carcinoma
Early-stage (T1 and T2) - Surgery or radiation therapy
Moderately advanced (T3): Radiation therapy and sometimes chemotherapy
Advanced (T4): Surgery (often followed by radiation therapy +/- chemotherapy) or sometimes chemotherapy + radiation therapy
239
What are the main morphological features of chronic inflammation
Infiltration with mononuclear cells
Tissue destruction and fibrosis
Attempts at healing by connective tissue replacement
240
Describe the pathogenesis of pneumonia
Microorganisms, pollution and debris are inhaled but evade the usual host defences
Pathogens can disrupt these systems by attaching & proliferating locally (e.g. influenza), paralysing cilia via toxins (e.g. h. influenzae), or evading death by phagocytosis (mycobacterium tuberculosis)
Once a pathogen reaches the lungs there is immune activation and a build up of fluid and cells in the alveoli
This leads to impaired gas exchange
241
How does sepsis promote coagulation
Many immune factors favor coagulation
| Stasis in small vessels leads to formation of thrombi
242
List the stages of cerebral abscess formation
Early cerebritis (day 1-4)
Late cerebritis (day 4-10)
Early capsule formation (day 11-14)
Late capsule formation (> 14 days)
243
What is the most effective way for infection to spread
Via the bloodstream
| From here, the pathogen can spread to all organs and produce a systemic response
244
How do you treat HSV1 encephalitis
Acyclovir 10mg/kg every 8hrs for 14-21 days
245
Which cells are recruited to the sites of inflammation
Leukocytes, antibodies and complement proteins
Some will have been circulating in the blood and are brought to the area via the circulation and become active (triggered by cellular signals)
Others are found in the tissues at all time and pick up invaders/changes
246
What are the potential outcomes of pleuritis/ pleural effusion
With treatment, most cases will resolve and the fluid is absorbed.
Sometimes there is minimal fibrosis if the effusion had a fibrinous component which is reorganised
If the effusion is substantial, it can prevent the lungs from expanding fully and may even cause collapse
- This would lead to respiratory distress
247
Which pathogens are the most common cause of viral meningitis
Enteroviruses
Influenza
Herpes simplex
Mumps
248
What is pericarditis
Inflammation of the pericardium
| Can be acute (majority) or chronic
249
How do infections spread through the CNS
Some viruses can proliferate in peripheral nerves and then travel up the axons to access the CNS - Varicella zoster
Bacteria can reach the CNS in the bloodstream where they can proliferate in the CSF as well as tissues - Neisseria meningitidis
250
What happens if the inflammatory response goes uncontrolled and becomes systemic
It can lead to SIRS and sepsis
Systemic features include: fever, production of acute-phase proteins, increased production of WBC, increased pulse and BP, rigors, anorexia and malaise (may be due to effect of cytokines on the brain)
251
How does TB cause haemoptysis
Apical lesions can expand into the adjacent lung, bronchi and vessels
252
What is the definition of contagious
Able to be transmitted from one human to another
253
How does a lung abscess present on CXR
Walled cavity
| Often with an air/fluid level
254
How does complete resolution occur
Macrophages will remove the cellular debris and microbes
Lymphatic system will reabsorb the oedema fluid
The damaged tissue is then regenerated by surviving cells or tissue stem cells (normal cells are restored)
255
What are some of the main complications of pneumonia
Lung abscess (if inadequately treated)
Respiratory failure
Hypotension (due to dehydration and vasodilation in sepsis)
AF (common in elderly) – resolves with treatment of infection.
Pleural effusion
Empyema
Systemic dissemination - endocarditis, meningitis, suppurative arthritis, metastatic abscesses
256
What are the symptoms of laryngeal cancer
```
Hoarse voice
Pain or difficulty when swallowing
Lump or swelling in the neck
Persistent cough or sore throat
Ear ache
Difficulty breathing
```
257
What causes pericarditis
There are a wide range of causes including infectious agents, disorders of the immune system, MI and cardiac surgery
258
Can leukocytes themselves cause tissue damage
Yes
| This can prolong inflammation
259
List some common pathogens of the urogenital tract
```
E coli (UTI)
candida albicans (disruption of vaginal flora)
STIs
```
260
Describe the macroscopic appearance of a cerebral abscess
Discrete lesion with central liquefactive necrosis
| Surrounding fibrous capsule
261
How can immune reactions such as hypersensitivity cause inflammation
Sometimes the immune system can attack the individuals own tissue in response to harmless stimuli
Can be directed against self-antigens (autoimmune disease), environmental stimuli (allergies)
This leads to persistent/ hard to cure inflammation as stimuli cannot be eliminated
262
How does an exudate form
There is increased blood flow to an area and the vessels become more permeable
This allows cells and plasma proteins to move out into the area
Common and normal occurrence in inflammation
263
How can primary TB become latent
Initial infection is controlled by the T cell response
The Ghon complexes progressively fibrose and leave a fibrocalcific nodule
Some viable organism s can remains dormant in the granulomas
264
What is the purpose of vasodilation in inflammation
This increases blood flow to the area to aid delivery of cells/fluid
265
What are the risk factors for TB drug resistance
Previous TB treatment
Contact with drug-resistant disease
Birth or residence in country where resistance is high
266
What are the macroscopic features of nasopharyngeal cancer
Most arise on the lateral wall of the nasopharynx
Most grow outwards
Usually a smooth, discrete raised nodule below the mucosa
Around 10% will be ulcerated
Cervical node mets are common
267
What are the physiological defenses of the oropharynx
Saliva, sloughing and coughing
268
How does HSV1 encephalitis cause death
Increased ICP leads to herniation
| Can also affect cerebral perfusion
269
What are some of the long term complications of HSV1 encephalitis
Behavioural issues, antegrade amnesia, seizures, difficulty with new tasks
270
Define the oropharynx
Extends from soft palate to epiglottis
271
What are the features of septic shock
DIC (clotting leads to tissue hypoxia)
Hypotensive shock (systemic hypotension)
Metabolic imbalances
Multiorgan failure
272
What are the complications of streptococcal toxic shock syndrome occur
Limbs removed through surgery
Serious scarring from having infected tissues removed
Between 3 and 7 in 10 people with STSS die
273
What are the clinical features of a cerebral abscess
Headache
Site dependent focal neurological signs
Seizures
Signs of raised ICP - N&V, double vision, confusion and drowsiness
274
What are the main causes of a pleural effusion
Occur due to primary pleural diseases such as infection or mesothelioma
Or it can be from secondary inflammation or infection
Other causes include: decrease in osmotic pressure (nephrotic), decreased lymph drainage (cancer) and increased intrapleural pressure (collapse)
275
How do animal vectors spread disease
Through their bites (e.g. Malaria and mosquitos)
| Can spread bacteria, viruses or protozoa
276
What is the most common subtype of pericarditis
fibrinous/serofibrinous
277
Give an example of a condition that causes purulent inflammation
Acute appendicitis
278
How do you treat strep throat
Usually self limiting - rest etc.
| Resistant to most common antibiotics but if one is given its phenoxymethylpenicillin
279
What are the common causative organisms of CAP
Typical: Strep. Pneumonia, H. influenzae, Moraxella catarrhalis
Atypical: Mycoplasma pneumoniae, staph. Aureus, Legionella sp., and chlamydia
Viruses only account for 15% of cases
280
Which diseases can present with granulomas
TB - granuloma is called a tubercle
| Crohn's and sarcoidosis
281
What factors increase your risk of respiratory infection
Smoking, being on a ventilator or CF all lead to damage of the mucocilliary system - more vulnerable
Immunocompromised hosts also a risk - PJ in AIDS
282
Describe the epidemiology of HSV1 encephalitis
Most common type
Children and the elderly are the most commonly infected and most severely affected
Male:female affected equally
Its sporadic across the globe and has no seasonal preference
283
Describe the inflammatory process of lobar pneumonia
You get the initial congestion from the classic acute inflammatory response (appears heavy and boggy)
Massive neutrophilic exudation with haemorrhage leads to red hepatisation
RBC disintegrates whilst fibro-purulent exudates remain leading to grey hepatisation
Finally you get resolution - enzymes digest the consolidated exudates
284
What is the definition of contamination
The accidental introduction of microorganisms
285
When does post-streptococcal glomerulonephritis occur
Occurs about 10 days after strep symptoms
286
Legionella causes pneumonia in which population groups
Colonises water tanks kept <60 degrees C (air-conditioning & hot water systems).
Immunocompromised patients
287
What is a pleural effusion
An accumulation of excess fluid in the pleural space
| Can be inflammatory or non-inflammatory in nature
288
How can ingestion lead to infection
Most common is through food or drink contaminated by faecal matter which leads to diarrheal diseases (faecal-oral route)
If a pathogen is acid resistant they can survive the usual protective mechanism
Or they can produce toxins or adhere to areas of damage
Affect the GI tract
289
How do you treat a cerebral abscess
Mainly antibiotics and surgery
Ceftriaxone for strep and vancomycin for staph
Surgery is either aspiration or craniotomy
290
Describe the aetiology of pneumonia
Caused by bacterial, viral or fungal organisms
In certain conditions there is impairment in the local (CF) or systemic (AIDS) immune system which puts people more at risk
Intubation inhibits complete clearance of microbes via mucociliary escalator which also increases risk
291
What are the symptoms of post-streptococcal glomerulonephritis
```
Red/brown urine
Oedema
Less urine
Fatigue (caused by a mild anemia)
Proteinuria
Hypertension
```
292
Describe the natural history of HSV1 encephalitis
```
Infected when young – cold sore virus
Remains latent for several years
Reactivates and presents acutely or sub acutely
Antiviral treatment for 14-21 days
Can have long term complications
```
293
Explain the relationship between pericarditis and URTIs, pneumonia and pleuritis
URTI and lung infections such as pneumonia can precede pericarditis
Areas of pneumonia or empyema can directly invade the pericardium and lead to purulent pericarditis
In this case the URTI etc. would be considered the primary infection site
294
How do you diagnose rheumatic fever
Throat swab for a group A strep infection
Blood test for group A strep antibodies
ECG & echocardiogram
295
What is the definition of community acquired pneumonia
Lung infection in a healthy individual that is picked up in the normal environment
They have had no recent healthcare exposure
296
Pseudomonas aeruginosa causes pneumonia in which population groups
Common in cystic fibrosis & neutropenic patients.
| Common cause of HAP, esp. in ITU or post-surgery
297
Which bacteria is in Group A strep
Streptococcus pyogenes
| Pyogenic so can produce pus
298
What are the pathologic features of pericarditis
Exudate is made up of blood and fibrinous/suppurative effusion.
If cancer is the underlying cause, then neoplastic cells may be found on cytology of the exudate.
299
How do you diagnose a pleural effusion
Chest X-ray - blunting of costophrenic angles and fluid level seen
US - useful for guidance
Diagnostic aspiration
Biopsy if aspiration is inconclusive
300
Describe the natural history of meningitis
Starts with exposure to the virus or bacteria
Takes between 3-7 days from infection for the inflammatory processes to take place and to see symptoms
Seek medical attention
Treatment – 1-2 weeks for bacterial or supportive management for 7-10 days for viral
Potential for long term complications
301
How do you diagnose laryngeal carcinoma
Laryngoscopy
Operative endoscopy
Biopsy + imaging tests for staging
302
How do you diagnose strep throat
Examination and swab
Can be diagnosed by rapid streptococcal antigen tests in pharyngitis and culture in other cases
Use the FeverPAIN score to differentiate from a viral infection
303
What causes aspiration pneumonia
Inhalation of gastric or oropharyngeal contents into the lower airways
Pneumonia occurs due to presence of foreign material in the lungs
304
What are the normal defenses of the respiratory system
Mucociliary clearance
The cough reflex
Resident alveolar macrophages & neutrophils
305
What causes an immune granuloma
Caused by a variety of agents that can induce a persistent T cell-mediated immune response
Occurs when the microbe is particularly hard to get rid off
306
What commonly leads to adherence mediastinopericarditis
Infection, surgery or radiation
307
Which pathogens are the most common cause of chronic meningitis
TB
| Cryptococcus
308
Describe the histology of the trachea
Lined by respiratory epithelium
Layer of basal lamina then lamina propria of CT
It has between 15-20 cartilage ‘C’ shapes
The open side has fibroelastic tissue and smooth muscle (trachealis muscle)
Also has many submucosal glands which secrete mucus onto the surface
309
What is the definition of a parasite
```
An organism that lives in or on, and benefits from, another organism whilst causing harm to its host.
Includes protozoa (unicellular)
```
310
Describe the role of T and B lymphocytes in chronic inflammation
They prolong the inflammation
They can secrete cytokines which promotes inflammation
Memory function may be key to prolonged inflammatory reactions
311
How do you treat meningitis empirically
Ceftriaxone IV 2g bd plus dexamethasone IV 10Mg qds
If over 65 or immunocompromised add in amoxicillin IV 2g 4hrly (listeria cover)
312
How do you diagnose HSV1 encephalitis
Lumbar puncture
EEG
MRI
PCR on CSF for HSV1
313
Describe serous inflammation
Exudation of cell-poor fluid into spaces created by tissue damage or into body cavities (pleural or pericardial)
No microbes present in fluid and little to no leukocytes
Fluid in cavities either comes from the plasma or secretions from the mesothelial cells due to local irritation
314
Purulent pericarditis often leads to chronic pericarditis - true or false
True - particularly constrictive
| the severe inflammation usually leads to scarring
315
Describe the pathogenesis of URTI
Organism is acquired by inhalation of infected droplets
It then successfully invades the mucosa of the upper airway, bypassing the bodies defenses
Once invaded the inflammatory response initiated
316
What are the common pathogens that infect the lower respiratory tract
Staph. aureus, Haemophilus influenzae, Mycobacterium tuberculosis
Mycoplasma pneumonia
317
What are the features of an chronically inflamed ulcer
Fibroblastic proliferation & scarring of margin & base of ulcer
Accumulation of lymphocytes, macrophages & plasma cells
318
How would a CSF sample appear in bacterial meningitis
```
Cloudy or purulent,
High pressure
High neutrophils
Increased protein
Markedly reduced glucose
```
319
What is the main protective mechanism of the UG tract
Frequent bladder emptying
