ENT Microbiology Flashcards by Patrick Stenhouse

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

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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 `

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What is the most common viral cause of a sore throat

Influenza and primary herpes simplex

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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

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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

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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

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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

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What is “quinsy”?

Peri-tonsillar abscess

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When will quinsy normally occur?

Usually a complication of tonsillitis

Streptococci most frequently cause unilateral infection in the palatine tonsils

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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)

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Which condition may result as a complication of an inadequately treated Streptococcus throat infection?

Rheumatic fever

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What are the key symptoms of Rheumatic fever?

Fever
Arthritis
Pancarditis

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Which condition involving the kidneys can become a late complication of a streptococcus throat infection?

Glomerulonephritis

(presents with haematuria, albuminuria and oedema)

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What is the treatment for a bacterial sore throat caused by S. pyogenes?

Penicillin

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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

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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

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What is the treatment for diptheria?

Antitoxin and supportive penicillin/erythromycin

(it is vaccine preventable and rare in the UK)

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How does candida present in the throat and mouth?

White patches in red/raw mucous membranes

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What causes thrush?

clinical manifestations?

Candida albicans (endogenous)

white patches on red, raw mucous membranes in throat

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How can thrush be treated?

Nystatin

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What is acute otitis media?

URTI involving middle ear

This happens as the infection passes via the Eustachian tube

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How doe acute otitis media typically present?

Infants/children
Ear ache
Discharge (if ear drum ruptures)

(hearing loss, fever and lethargy are also common)

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Which bacteria are most commonly found to infect the middle ear?

Streptococcus pneumoniae
Haemophilus influenzae
Streptococcus pyogenes
Moraxella catarrhalis

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How can middle ear infections be diagnosed?

Only by discharge swabs - only when the eardrum perforates

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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

1. Streptococcus pneumoniae 2. Haemophilus influenzae 3. Streptococcus pyogenes 4. 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)

What is the treatment for acute sinusitis?

1st line - Penicillin 2nd line - Doxycyline (clarithromycin in children)

Why must doxycyline be avoided in children?

It is toxic to growing teeth and bones

What is the term given to inflammation of the outer ear canal? what is the most common cause?

Otitis externa - aka swimmers ear acute bacterial infection

Why may hearing be impacted in otitis externa? what are the bacterial causes? fungal? treatment?

Discharge and increased amounts of ear wax may be associated staph aureus (most common) proteus spp pseudomonas aeruginosa (most common\_ Fungal = aspergillus niger, candida albicans - mainstay of treatmetn is cleaning and topical antifungal therapy treatment - just a washout of the ear;

In the early stages otitis externa will be red and \_\_\_\_\_\_\_ how do you define acute?

In the early stages otitis externa will be red and **itchy** ## Footnote **also there will be swelling** **can become sore and painful** **lasting three weeks or less**

What is malignant otitis?

Extension of otitis externa into the bone surrounding the ear canal

Why is malignant otitis a fatal condition without treatment?

The mastoid and temporal bones are affected by osteomyelitis which will also begin to involve the meninges

What are the symptoms and signs for malignant otitis?

1. Pain and headache (worse than signs would suggest) 2. Granulation tissue at bone/cartilage junction of ear canal 3. Facial nerve palsy

Which pathogen usually causes malignant otitis?

Pseudomonas aeruginosa

What are the key risk factors for malignant otitis?

Diabetes Radiotherapy to the head/neck

What are the common causes for otitis externa?

Bacterial: 1. S. aureus 2. Pseudomonas aeruginosa Fungal: 1. Aspergillus niger 2. Candida albicans

What should be avoided when affected by otitis externa?

Swimming (there ear is constantly wet damp with regular swimming increases likelyhood of bacterial growth)

How should fungal otitis externa be treated?

Topical clotrimazole

How is otitis externa treated if the cause is bacterial?

Gentamicin (0.3%) drops

What is the classic triad of symptoms seen in most patients with infectious mononucleosis?

1. Fever 2. Pharyngitis 3. Lymphadenopathy

Where are the lymph nodes often most prominent in infectious mononucleosis?

Neck (cervical)

Why are ampicillin and amoxicillin not recommended to treat infectious mononucleosis?

Cause diffuse rash in many patients

Which LFT is most raised in infectious mononucleosis?

ALT

Which organs are most commonly affected by infectious mononucleosis?

1. Respiratory tract 2. Skin (rash (25%)) 3. Liver (jaundice/hepatitis in few patients) 4. Spleen (splenomegaly (50%)) - avoid sport for 6 weeks incase of rupture 5. Palate (palatal petechiae) 6. Blood (leucocytosis, presence of atypical lymphocytes in blood film)

Atypical lymphocytes can occur with any viral infection, what makes this sign different in infectious mononucleosis?

It occurs in around **15%** of lymphocytes

How long does infectious mononucleiosis normally last?

2-4 weeks

Why should sport be avoided for 6 weeks in infectious mononucleiosis?

Splenomegaly many occur with the condition and sport may induce a rupture

What are the main complications associated with infectious mononucleiosis?

1. Anaemia 2. Thrombocytopenia 3. Splenic rupture 4. Upper airway obstruction 5. Increased risk of lymphoma

What is different about Epstein barr infection in those in early childhood versus those over 10 years old?

Primary infection in early childdhood is unlikely to cause infectious mononucleiosis, whereas after 10 years it is likely

What are the two phases for EBV acquisition? how is this confirmed in the lab?

1-6 years 14-early 20s IgM epstein-barr virus positive

Why may EBV induce autoimmunity?

The virus replicates in B cells which leads to abnormal antibody production

What is the treatment for infectious mononucleiosis?

Bed rest No sport Paracetamol Corticosteroids in severe cases

Which pathogens can cause similar infection to infectious mononucleiosis?

1. Cytomegalovirus 2. Toxoplasmosis 3. Primary HIV infection

How can infectious mononucleiosis be differentiated from primary HIV infection?

Risks in history Presence of diarrhoea (in HIV)

Which type of virus commonly causes oral lesions?

Herpes simplex type 1

What is HSV2 more commonly associated with?

herpes that appear in the genital area

What is the percentage of adults that have been infected by the herpes virus?

70% of adults

how is herpes transmitted?

gential or oral contact

What are some clinical manifestations of herpes?

frequently asymptomatic recurrent/perioral lesions (cold sores) genital lesions or occular infections (herpetic keratitis)

How can primary gingivostomatitis be treated? what age category usually gets this disease? What are some of the symptoms

Aciclovir It is a disease of pre-school children Multiple painful oral lesions - with local lympahdenopathy

Why is HSV1 likely to reactivate?

Inactive virus can remain latent in trigeminal ganglia

What is herpetic whitlow?

Lesion (whitlow) on a finger or thumb caused by the herpes simplex virus - infected by a break in the skin.

Which pathogen causes herpangina? What are the clinical manifestations?

Coxsackie A viruses vesicles/ ulcers on soft palate - fever and painful papulo-vesiculo-ulcerative oral enanthem

Which pathogen causes hand, foot and mouth disease? Where is an outbreak common and how is it tested for clincially? Clinical symptoms?

Coxsackie viruses Common outbreaks within families and it is diagnsoed by PCR Oral enanthem and macular/maculopapular rash of the hands and feet

Which systemic diseases may cause recurrent apthous ulcers? What are they? Where are they confied to?

Behcet's disease Gluten sensitive enteropathy or IBD Reiter's syndrome Drugs reactions Skin diseases (lichen planus, pemphigus or pemphigoid) painful oral lesions that appear as localised round, yellowish central exudate Confined to the mouth - each ulcer lasts usually less than 3 weeks

Which pathogen cause syphilis? Where is the most common site?

Treponema pallidum Genital but oral and pharyngeal lesions can be the site of entry - if left undiagnosed can lead to secondary and tertiary syphillis

How does primary syphilis present?

Chancre (painless ulcer) at site of entry

How are cold sores reativated? What is the treatment?

From nerves and this causes active infection - aciclovir

What do I mean when I say patients that experince a reactivation of HSV1 experince prodromo symptoms 24 hrs before onset of cold sore

Pain, burning and tingling

When would a sample be taken from a pateint that has suspected Hepes simplex virus? How is it diagnosed?

new mucosal or cutaneous lesions or recurrent muscosal or cutaneous leesions of unclear eitology PCR test done on DNA testing

Which pateints should be treated with HSV1?

Give an example of a drug that causes neutropenia?

Carbimazole

ENT Microbiology Flashcards

(78 cards)