ENT Microbiology Flashcards
What generally is responsible for causing inflammation of the throat and pharynx?
What are some common causes of a sore throat?
what is the age bracket thaty sore throats usually happen in?
Infectious causes (2/3rd viral)
(non-infectious causes are rare)
common cold, influenza, strep infection
5-24 year olds
If sore throat and lethargy persist into the second week, and if the patient is 15-25 years old, what should be suspected?
What is this caused by?
Infectious mononucleosis (glandular fever)
Epstein barr virus `
What is the most common viral cause of a sore throat
Influenza and primary herpes simplex
Which pathogen causes infectious mononucleosis? what is this infection also known as?
What are some complications of a sore throat?
What is teh triad of symptoms for this?
Epstein barr virus - glandualr fever - the kissing disease
Ottis media (most common), peritonsilar abcess (quinsy) and parapharyngeal abcess
What is the most common cause of a bacterial sore throat?
what is the clinical manifestation?
What is the treament?
Streptococcus pyogenes
acute follicular tonsilitis
penicillin
What causes the beta haemolysis associated with S. pyogenes?
Is strep pyogenes gram +ve or neg?
LMW toxin diffusing out of the colonies
Gram positive cocci in chains
What are some late complications of strep pyogenes infection?
What scoring system is used in the diagnosis of GAS?
Rheumatic fever - 3 weeks post sore throat
glumerulonephritis - 1-3 weeks post sore throat
Centor criteria: one point for each
- tonsillar exudate
tender anterior cervical lymph nodes
history of fever
absence of cough
if all 4 = 52% risk of having the bacteria
FEVERpain score can also be used (look this up)
the antiboitc that is used is phenoxymethylpenicillin
What is “quinsy”?
Peri-tonsillar abscess
When will quinsy normally occur?
Usually a complication of tonsillitis
Streptococci most frequently cause unilateral infection in the palatine tonsils
What is Lemierre’s syndrome?
An infection, most commonly by F. necrophorum, of the posterior compartment of the lateral pharyngeal space as a complication of a bacterial sore throat infection in young, otherwise healthy adults
It involves a triad of symptoms:
- Pharyngotonsillar or odontogenic infection
- Lateral pharyngeal space invasion leading to internal jugular vein thrombosis
- Metastatic disease (sepsis or lung involvement)
(it is also known as human necrobacillosis and postanginal sepsis)
Which condition may result as a complication of an inadequately treated Streptococcus throat infection?
Rheumatic fever
What are the key symptoms of Rheumatic fever?
- Fever
- Arthritis
- Pancarditis
Which condition involving the kidneys can become a late complication of a streptococcus throat infection?
Glomerulonephritis
(presents with haematuria, albuminuria and oedema)
What is the treatment for a bacterial sore throat caused by S. pyogenes?
Penicillin
Which pathogen causes diptheria? - diptheria comes from the latin word leather (refers to the tough pharyngeal membrane that develops at the back of the throat)
Corynebacterium diphtheriae
How does diptheria affect the posterior pharynx?
Causes severe sore throat
Grey/white membrane across pharynx
produces a potent exotoxin which is cardiotoxic and neurotoxic
What is the treatment for diptheria?
Antitoxin and supportive penicillin/erythromycin
(it is vaccine preventable and rare in the UK)
How does candida present in the throat and mouth?
White patches in red/raw mucous membranes
What causes thrush?
clinical manifestations?
Candida albicans (endogenous)
white patches on red, raw mucous membranes in throat
How can thrush be treated?
Nystatin
What is acute otitis media?
URTI involving middle ear
This happens as the infection passes via the Eustachian tube
How doe acute otitis media typically present?
- Infants/children
- Ear ache
- Discharge (if ear drum ruptures)
(hearing loss, fever and lethargy are also common)
Which bacteria are most commonly found to infect the middle ear?
- Streptococcus pneumoniae
- Haemophilus influenzae
- Streptococcus pyogenes
- Moraxella catarrhalis
How can middle ear infections be diagnosed?
Only by discharge swabs - only when the eardrum perforates
How are infections of the middle ear treated?
Most resolve spontaneously
1st line - Amoxicillin
2nd line - Erythromycin
What is acute sinusitis?
Mild discomfort over the frontal or maxillary sinuses due to congestion often seen in patients with URTI
What does severe pain and tenderness with purulent nasal discharge indicate in a patient with acute sinusitis?
Secondary bacterial infection
Which bacteria commonly affect the sinuses in acute sinusitis
- Streptococcus pneumoniae
- Haemophilus influenzae
- Streptococcus pyogenes
- Moraxella catarrhalis
How long does acute sinusitis usually last?
2.5 weeks
When should antibiotics be used for acute sinusitis?
Severe or deteriorating cases lasting longer than 10 days
What is the definition of chronic sinusitis?
Sinusitis lasting longer than 4 weeks
(Acute is < 4 weeks)