06-10-23 - Infections of the Sensory System Flashcards
Learning outcomes
- Describe the normal host defence mechanisms of the upper respiratory tract and the eye
- Be able to identify the possible sites of infection in the upper respiratory tract, the ear and the eye
- Detail the infective agents which cause infections of the upper respiratory tract, the eye, the ear, and the oral cavity
- Recognise and describe the clinical features infections of the upper respiratory tract infections, the eye, the ear, and the oral cavity
What are the 2 types of immunity?
What are the 3 parts of the first line defence?
What are the 4 parts of second lien defence?
What are the 3 parts of third line defence?
- 2 types of immunity:
- Non-Specific Defences (Innate immunity):
- 3 parts of the first line defence:
1) Skin
2) Mucous membranes
3) Secretions of skin and membranes - 4 parts of second lien defence:
1) Phagocytic leukocytes
2) Antimicrobial proteins
3) Inflammatory response
4) Fever - Specific Defences (Adaptive immunity)
3 parts of third line defence:
1) Lymphocytes
2) Antibiotics
3) Memory cells
What are 9 innate ocular defences?
What are 6 adaptive ocular defences?
- 9 innate ocular defences:
1) Orbits
2) Eye lids
3) Tears
4) Mucin
5) Ocular epithelium
6) Ocular bacterial flora
7) Antibacterial factors (enzymes)
8) Macrophages
9) Natural killer cells - 6 adaptive ocular defences:
1) Eye-associated lymphoid tissue
2) Langerhans cells
3) Immunoglobulins
4) T-lymphocytes
5) B-lymphocytes
What is a ‘blow-out’ fracture?
- On a CT scan, a “blow-out” fracture occurs to the orbital floor, with contents herniating into the floor of the maxillary sinus
- This is part of the innate defence of the eye using the bony orbit
What type of defence is the rear-film and cornea part of?
What line of defence are they?
- The tear film and cornea are part of the innate defence
- They have:
1) Physical Barrier (1st Line)
2) Chemicals & Cells (2nd line)
What defence is the ocular lymphoid tissue part of?
- Ocular Lymphoid Tissue is 2nd line (innate) and 3rd line (adaptive) defence
What is the role of lysozyme?
Where are peptidoglycans found in gram-negative and gram-positive bacteria?
What 5 parts of innate defence contain lysozyme?
- Lysozyme is an enzyme that cleaves Peptidoglycans
- Gram-negative bacteria are surrounded by a thin peptidoglycan cell wall, which itself is surrounded by an outer membrane containing lipopolysaccharide.
- Gram-positive bacteria lack an outer membrane but are surrounded by layers of peptidoglycan many times thicker than is found in the Gram-negatives
- 5 parts of innate defence contain lysozyme:
1) Tears
2) Saliva
3) Mucous
4) Macrophages
5) Neutrophils
What are 3 roles of lactoferrin?
What 5 parts of the innate defences contain lactoferrin?
- 3 roles of lactoferrin:
1) Binds iron – starves bacteria & fungi
2) Disrupts cells walls
3) Blocks viral lipoprotein bonds– anti-viral - 5 parts of the innate defences contain lactoferrin:
1) Tears
2) Saliva
3) Mucous
4) Milk (Lacto – ferrin)
5) Neutrophils
What is the role of lactoferrin and lysozyme together?
- Lactoferrin and lysozyme work together to defeat gram negative bacteria
- Lactoferrin alters the permeability of the lipopolysaccharide layer, giving lysozyme access to the peptidoglycan layer
What are 5 microorganisms in the ocular biome?
What is the role of the biome?
- 5 microorganisms in the ocular biome:
1) Staphylococcus
2) Streptococcus
3) Propionibacterium
4) Corynebacterium
5) Fungi too - The ocular biome competitively inhibit growth of pathogenic organisms
What are 4 common infections of the eye?
What are 2 rare eye infections?
What causes/types for each infection?
- 4 common infections of the eye:
1) Conjunctivitis – Adult & neonatal
2) Keratitis – Viral, bacterial
3) Onchocerciasis – Parasitic infection
4) Orbital Cellulitis – Pre and post-septal - 2 rare eye infections:
1) Retinochoroiditis – HIV/AIDS/Toxoplasma
2) Endophthalmitis – Post-op and endogenous
What are 4 viruses that cause Common Viral Conjunctivitis?
What are 6 signs/symptoms of Common Viral Conjunctivitis?
- 4 viruses that cause Common Viral Conjunctivitis:
1) Coronaviruses
2) Rhinoviruses
3) Respiratory Syncytial Virus
4) Parainfluenza - 6 signs/symptoms of Common Viral Conjunctivitis:
1) Sticky eyes
2) Watery
3) Pink (conjunctival erythema)
4) Discomfort / itchy eyes
5) Self-limiting
6) Rarely cause any serious damage
What are 6 signs/symptoms of Adenovirus Conjunctivitis?
- 6 signs/symptoms of Adenovirus Conjunctivitis:
1) Bilateral, very sticky, red, painful
2) Enlargement of ipsilateral periauricular lymph node
3) Sore throat and cough - miserable
4) May have corneal involvement - Punctate keratitis
5) Symptomatic treatment
6) Keratitis (corneal infections) can last a long time
What are 3 signs/symptoms of Bacterial Conjunctivitis?
What are 3 causes of bacterial conjunctivitis?
What are 2 treatments for bacterial conjunctivitis?
- 3 signs/symptoms of Bacterial Conjunctivitis:
1) Much like viral but …
2) Discharge more yellow and thick
3) Will not typically go away unless given Abx - 3 causes of bacterial conjunctivitis:
1) Haemophilus influenzae
2) Streptococcus pneumoniae
3) Moraxella - 2 treatments for bacterial conjunctivitis:
1) Chloramphenicol
2) Fusidic Acid
What are 3 causes of neonatal conjunctivitis?
- 3 causes of neonatal conjunctivitis:
1) A blocked tear duct,
2) Irritation produced by the topical antimicrobials given at birth,
3) infection with a virus or bacterium passed from the mother to her baby during childbirth:
* Neisseria gonorrhoea
* Chlamydia trachomatis
* Haemophilus influenza streptococcus
What is keratitis?
What are the 3 types of Keratitis?
- Keratitis (also known as “corneal ulcer”) is an inflammation of the cornea
- 3 types of Keratitis:
1) Bacterial
2) Viral - HSV & HZO (Herpes simplex virus and Herpes Zoster Ophthalmicus)
3) Trachoma (caused by bacterium Chlamydia trachomatis.)
What 3 bacteria are responsible for 80% of cases of bacterial corneal ulcers?
Which type is the most frequent and pathogenic?
What else should also be considered?
- 3 bacteria are responsible for 80% of cases of bacterial corneal ulcersL
1) Staphylococcus aureus
2) Streptococcus pneumoniae
3) Pseudomonas species
* Pseudomonas aeruginosa is the most frequent and the most pathogenic ocular pathogen which can cause corneal perforation in just 72 hours
- Fungi in organic matter injury must also be considered
Impairment of what 4 ocular defences can lead to cornea ulcers?
- Impairment of 4 ocular defences can lead to corneal ulcers:
1) Tear film deficiencies
* Inadequate corneal protection due to keratoconjunctivitis sicca can lead to ulceration
2) Eyelid malformation / dysfunction
* Can lead to exposure of the cornea and corneal ulceration.
* Examples include: lagophthalmos, macropalpebral fissure, cranial nerve palsy’s, ectropion.
3) Endogenous cause
* Mechanical abrasion due to: entropion, distichiasis, ectopic cilla, trichiasis, masses.
4) Exogenous cause
* Trauma (foreign bodies, cat and baby and bush/tree scratches).
In what patients is HSV keratitis often seen?
What eye does it affect?
What are 5 signs of HSV keratitis?
How do we treat HSV keratitis?
- HSV keratitis is often in ‘run down’ patients and or a history of ‘cold sore’ on lips/nose in the past or recently
- It is always unilateral – always same eye
- 5 Signs of HSV keratitis:
1) Painful
2) Red
3) Watery
4) Photophobic
5) Dendritic ulcer - new vessels, loss of sensation, scarring - often recurrent - HSV keratitis is treated with topical and oral aciclovir – often on oral low dose for months and years
What is trachoma caused by?
What can it lead to?
What is it the main cause of?
Describe the 5 stages of trachoma (in picture)
- Trachoma is caused by Chlamydia trachomatis infection
- It can lead to chronic keratoconjunctivitis
- Trachoma is the main cause of infective blindness
- 5 stages of trachoma (in picture)
Describe the 4 steps of eradication of trachoma (in picture)
What is Onchocerciasis caused by?
What does it lead to?
How is it treated?
- Onchocerciasis is caused by a parasitic infection
- It leads to river blindness
- It is treated by Ivermectin treatment (antiworm treatment)
What is the role of the orbital septum?
How is orbital cellulitis classed?
- The orbital septum delineates the anterior eyelid soft tissues from the orbital soft tissue.
- Infections anterior to the orbital septum are classified as preseptal cellulitis and those posterior to the orbital septum are termed post-septal orbital cellulitis (aka orbital cellulitis)
What are 4 infections that cause orbital cellulitis?
What 5 conditions can occur when there is spread of infection into deeper structures?
What are 8 signs of orbital cellulitis?
- 4 infections that cause orbital cellulitis:
1) Haemophilus influenza
2) Staphylococcus aureus
3) Streptococcus pneumoniae
4) beta-hemolytic streptococci - 5 conditions can occur when there is spread of infection into deeper structures:
1) Orbital abscess
2) Meningitis
3) Cavernous sinus thrombosis
4) Optic nerve damage
5) Bacteriemia - 8 signs of orbital cellulitis:
1) Swelling
2) Redness
3) Pain
4) Proptosis
5) Reduced Visual Acuity
6) RAPD relative afferent pupillary defect
7) Limited eye movements
8) Diplopia with pain
HIV/AIDS: Ocular Manifestations. What do HIV/AIDS/Toxoplasma cause?
Describe conditions that can be present with HIV/AIDS when the CD4+ T-cell count is below:
1) 500/µL (1)
2) 250/µL (2)
3) 100/µL (4)
- HIV/AIDS: Ocular Manifestations
- WhatHIV/AIDS/Toxoplasma causes Retinochoroiditis
- Conditions that can be present in HIV/AIDS when the CD4+ T-cell count is below:
1) 500/µL
* TB
2) 250/µL
* Toxoplasmosis
* Pneumocystosis
3) 100/µL
* CMV
* Mycobacterium avium complex
* Cryptococcosis
* Microsporidiosis
What are 3 treatments of Toxoplasmosis?
- 3 treatments of Toxoplasmosis:
1) Oral pyrimethamine
2) Sulfadiazine
3) Corticosteroids
What occurs in late HIV disease?
What is the treatment for this?
- In late HIV disease, there can be CMV retinitis (when CDT4+ levels are <100/ul)
- The treatment for this is Antiviral Ganciclovir
How common is Endophthalmitis?
After what 3 clinical scenarios can Endophthalmitis occur?
What is the treatment for Endophthalmitis?
- Endophthalmitis is rare but serious
- After 3 clinical scenarios can Endophthalmitis occur:
1) Intra-ocular operation e.g. cataract surgery
2) Trauma with inoculation of foreign body
3) Complication of systemic infection
- Treatment for Endophthalmitis is intra-ocular & systemic antibiotics +/- vitrectomy
What are the 2 types of immunity?
What are the 3 parts of the first line defence?
What are the 4 parts of second lien defence?
What are the 3 parts of third line defence?
- 2 types of immunity:
- Non-Specific Defences (Innate immunity):
- 3 parts of the first line defence:
4) Skin
5) Mucous membranes
6) Secretions of skin and membranes - 4 parts of second lien defence:
5) Phagocytic leukocytes
6) Antimicrobial proteins
7) Inflammatory response
8) Fever - Specific Defences (Adaptive immunity)
3 parts of third line defence:
4) Lymphocytes
5) Antibiotics
6) Memory cells
What are the 3 innate and adaptive defence mechanisms of the Upper Respiratory Tract?
- 3 innate defence mechanisms of the Upper Respiratory Tract:
1) Physical
2) Cells
3) Chemicals - 3 adaptive defence mechanisms of the Upper Respiratory Tract:
1) T Cells
2) B Cells
3) Antibodies
What are the 3 innate and adaptive defence mechanisms of the ear?
- 3 innate defence mechanisms of the ear:
1) Physical
2) Cells
3) Chemicals - 3 adaptive defence mechanisms of the ear?
1) T Cells
2) B Cells
3) Antibodies
Label the structures of the tympanic membrane (in picture)
In what groups is Otitis Media most common?
What is it mainly caused by?
What are the 3 microorganisms that cause otitis media?
What are 7 signs/symptoms of otitis media?
What are 3 ways otitis media can present in the tympanic membrane?
What can be used to treat this?
- Otitis media is Most common in infants and small children
- Otitis media is 50% viral in origin
- 3 microorganisms that cause otitis media:
1) Main cause – RSV (Respiratory Syncytial Virus)
2) S. pneumoniae
3) H. influenzae - 7 signs/symptoms of otitis media:
1) Pulling at ears
2) Red ears
3) Fever
4) Crying
5) Poor feeding
6) Restlessness
7) May result in hearing difficulties and delayed learning - 3 ways otitis media can present in the tympanic membrane:
1) ‘Glue’ ear – fluid in middle ear
2) Bulging ear drum and dilated vessels
3) Chronic suppurative otitis media - Ear Grommets are small tubes that are placed in the ear during surgery.
- It drains fluid away and keeps the eardrum open
What is mastoiditis a complication of?
What are 6 signs/symptoms of mastoiditis?
What is the treatment for this?
- Mastoiditis is a Severe complication of Otitis media, where there is a spread of infection from middle ear to mastoid aircells via the mastoid antrum
- 6 signs/symptoms of mastoiditis:
1) Ongoing or recent AOM (acute otitis media)
2) Redness
3) Tenderness and pain behind the ear
4) Pushed forward pinna
5) Fever
6) Fatigue - Treatment - If child or unwell, referral to ENT inpatient for IV antibiotics and investigation including imaging / blood tests
What is sinusitis?
What is it associated with?
What are the 3 sinuses typically affected by sinusitis?
What prevents clearing of the infection?
What is it exacerbated by?
What does sinusitis typically follow?
What are 3 symptoms of sinusitis?
What is the treatment for sinusitis?
- Sinusitis is inflammation of the sinuses due to pathogen invasion of the air spaces
- It is associated with the URT (upper respiratory tract infection)
- 3 sinuses typically affected by sinusitis:
1) Maxillary
2) Facial
3) Ethmoid - Mucosal swelling prevents muco-ciliary clearance of infection
- Sinusitis is exacerbated by local accumulation of inflammatory bacterial products
- 3 Symptoms of sinusitis:
1) Nasal blockage or discharge
2) Facial pain/pressure
3) +/- loss of smell - Treatment for sinusitis - Typically self-limiting 2-3 weeks, little evidence for Abx.
What are 6 viral causative agents of Acute Pharyngitis – “Sore Throat”?
What are 3 bacterial causative agents of acute pharyngitis?
What is this condition often associated with?
What are 8 symptoms of acute pharyngitis?
What is the management of acute pharyngitis?
What patient should we be worried about?
- 6 causative agents of Acute Pharyngitis – “Sore Throat”:
1) Cytomegalovirus (CMV)
2) Epstein-Barr virus (EBV)
3) Herpes simplex virus type I (HSV-1)
4) Rhinovirus
5) Coronavirus
6) Adenovirus - 3 bacterial causative agents of acute pharyngitis:
1) Streptococcus pyogenes
2) Haemophilus influenzae
3) Corynebacterium diphtheriae - Pharyngitis is often is associated with pharyngeal exudate and cervical lymphadenopathy
- 8 symptoms of acute pharyngitis:
1) Sore throat
2) Reduced oral/fluid intake
3) Fatigue
4) Lethargy
5) Fever
6) Headache
7) Nausea
8) Vomiting. - Management: Self-limiting for most, antibiotics need to be considered for some.
- Worry about patients taking DMARDs (Disease-modifying antirheumatic drugs), Carbimazole, HIV, Chemotherapy
Describe Scores 1-4 for the fever pain score
- Scores 1-4 for the fever pain score:
1) A score of 0-1 is associated with 13-18% isolation of streptococcus (close to background carriage rates).
* No antibiotics recommended.
2) Score of 2 is associated with 30-35% isolation of streptococcus.
* Delayed antibiotic may be appropriate.
3) Score of 3 is associated with 39-48% isolation of streptococcus.
* Delayed antibiotic may be appropriate.
4) A score of 4 or more is associated with 62-65% isolation of streptococcus.
* Consider antibiotics if symptoms are severe or a short-delayed prescribing strategy may be appropriate (48 hours)
What is a Peritonsillar abscess (Quinsy)?
What is it a complication of?
What are 7 signs/symptoms of peritonsillar abscesses?
What are the 6 parts of the management of peritonsillar abscesses?
What are complications of peritonsillar abscesses?
- A Peritonsillar abscess (Quinsy) is a Collection of pus between the tonsillar capsule and superior constrictor muscle.
- 7 signs/symptoms of peritonsillar abscesses:
1) Fever
2) Pain
3) Trismus (lock-jaw)
4) general malaise
5) Hot-potato voice
6) Unilateral swelling
7) Deviation of uvula - 6 Parts of the management of peritonsillar abscesses:
1) Same day hospital admission to ENT
2) Needle aspiration / drainage,
3) IV antibiotics (Penicillin based)
4) IV Steroids
5) Analgesia
6) IV Fluids until oral route available. - Complications - Retropharyngeal or deep neck space infection in fascial planes of the neck,
What is the cause of Glandular Fever?
Where does EBV replicated?
What are 12 signs/symptoms of Glandular fever?
What are 5 parts of the diagnosis of glandular fever?
- Glandular Fever is caused by Epstein-Barr Virus (EBV)
- EBV Replicates in B lymphocytes
- 12 signs/symptoms of Glandular fever:
1) Swollen tonsils and uvula
2) Petechiae on the soft palate(pinpoint non-blanching spots)
3) White exudate
4) Fever
5) Headache
6) Malaise
7) Sore throat
8) Anorexia
9) Palatal petechiae
10) Cervical lymphadenopathy
11) Splenomegaly
12) Mild hepatitis - 5 parts of the diagnosis of glandular fever:
1) EBV Serology
2) FBC
3) LFTs
4) EBV IgM – Acute 4-6 weeks
5) EBV IgG – Lifelong (Indicative of past infection)
What is Acute Epiglottitis caused by?
Where is Haemophilus influenza present in healthy people?
What % of reduction of acute epiglottitis cases has there been since vaccination has been available?
What are 4 signs and symptoms of acute epiglottitis?
What group is this most often seen in?
How severe is it?
When should we not examine a child with suspected epiglottitis?
- Acute Epiglottitis is Haemophilus influenza
- Haemophilus influenza is Present in nasopharynx of 75% healthy people
- 88% reduction in cases since vaccine in 1992
- 4 Signs and symptoms of acute epiglottitis:
1) High fever
2) Bacteraemia
3) Massive oedema of the epiglottis – lead to tripod position
4) Severe airflow obstruction – leads to Stridor and Dyspnoea - Most often seen in young children 2 to 6 years of age
- MEDICAL EMERGENCY needing 999 ambulance to hospital for intubation and IV antibiotics.
- Do Not examine a child with suspected epiglottitis without an anaesthetist.
Tripod position in epiglottitis (in picture)
What is Diphtheria caused by?
What groups does this disease typically affect?
Where does Corynebacterium diphtheriae?
How is it transmitted?
What are 5 signs/symptoms of diphtheria?
How do we diagnose diphtheria?
What are 3 parts of the treatment of diphtheria?
- Diphtheria is caused by corynebacterium diphtheriae
- It is typically a childhood disease
- Corynebacterium diphtheriae colonises pharynx, larynx and nose (rarely skin and genital tract)
- Transmission is via aerosol
- 5 signs/symptoms of diphtheria:
1) Sore throat
2) Fever
3) Formation of pseudomembrane
4) Lymphadenopathy
5) Oedema of anterior cervical tissue - Diphtheria diagnosis is made on clinical grounds as therapy is usually urgently required
- 3 parts of the treatment of diphtheria:
1) Prompt anti -toxin therapy administered intramuscularly
2) Concurrent antibiotics (penicillin or erythromycin)
3) Strict isolation and contact tracing
What is mumps caused by?
What are 8 symptoms of mumps?
What are complications of mumps?
How are mumps treated?
- Mumps is a viral illness caused by a paramyxovirus, a member of the Rubulavirus family
- 8 Symptoms of mumps?
1) Discomfort in the salivary glands (in the front of the neck) or the parotid glands (immediately in front of the ears).
* Either of these glands may become swollen and tender.
2) Difficulty chewing.
3) Pain and tenderness of the testicles.
4) Fever.
5) Headache.
6) Muscle aches.
7) Tiredness.
8) Loss of appetite.
- Complications of mumps include the swelling of various part s of the body e.g brain, testicles, spinal cord tissue
- There is no treatment for mumps
Describe the 3 vaccines given at 8 weeks old (in picture)
Describe the 3 vaccines given at 12 weeks old
Describe the 2 vaccines given at 16 weeks old
Describe the 4 vaccines given at 1 year old
Describe the 2 vaccines given at 3 years 4 months old or soon after
Describe the 3 vaccines given from 12 to 14 years old
