Microbiology of ENT infections Flashcards
How can infections of the throat and pharynx be diagnosed?
Throat swab
What is the cause of the large majority of sore throats? How is this clinically relevant?
Viral infections
NO ANTIBIOTICS
What is the most common cause of bacterial sore throats?
Strep pyogenes (group A strep)
How does strep. pyogenes sore throat present?
Acute follicular tonsillitis
How is bacterial sore throat treated?
Oral penicillin Oral clarithromicin (if allergic)
What is the criteria for prescribing antibiotics to sore throats?
Cervical lymphadenopathy
Absence of cough
Purulent tonsils
Fever
What are the features of strep pyogenes?
Gram positive cocci chains
Beta haemolytic
What are the acute complications of bacterial sore throat?
Peritonsillar abcess (quincy)
Sinusitis
Otitis media
Scarlet fever
What is scarlet fever?
Infectious bacterial disease (step. pyogenes) causing fever and red rash
What protection procedures are indicated in quincy?
SICP
Contact precautions
Risk assess for droplet protection
What are the late complications of strep. sore throat?
Rheumatic fever
Glomerulonephritis
How does rheumatic fever present?
Weeks after sore throat
Pancarditis
Fever
Arthritis
How does glomerulonephritis present?
Weeks after sore throat
Haematuria
Albuminuria
Oedema
What causes diptheria?
Corynebacterium diphtheriae
How does diptheria present?
Severe sore throat
Grey-white pseudomembrane across pharynx
What is effect does the diptheria endotoxin have on certain tissues?
Cardiotoxic
Neurotoxic
How common is diptheria?
Uncommon in UK
The diptheria vaccine is which type of vaccine?
Extracted toxin
How is diptheria treated?
Supportive
Anti-toxin
Penicillin OR erythromycin
How does oral candida (thrush) present?
White patches on top of raw, red mucous membranes in the mouth and throat
What causes thrush?
Candida albicans (usually endogenous)
How is oral candida treated?
Nystatin suspension (topically)
What is acute otitis media?
An upper respiratory infection which spreads to the middle ear via the eustachian tube
Which age group gets acute otitis media?
Infants & children
How does acute otitis media present?
Earache
What is the cause of acute otitis media?
Viral –> secondary bacterial infection
Which bacteria commonly cause acute otitis media?
Strep pyogenes
Haemophilus influenzae
Strep pneumonia
How is acute otitis media diagnosed?
Clinically
Swab can be taken (only if eardrum perforates)
How is acute otitis media treated?
Often self resolving
When are antibiotics indicated in the treatment of acute otitis media?
Bilateral in
Which antibiotics are used in the treatment of acute otitis media?
Amoxicillin
Clarithromycin if allergic
How does acute sinusitis present?
Discomfort over maxillary or frontal sinuses due to congestion
Pain which gets worse on bending/moving head in certain directions
What typically precedes acute sinusitis?
Upper respiratory tract infection (viral)
What would make you think of secondary bacterial infection with regard to acute sinusitis?
Severe pain over sinuses
Purulent nasal discharge
Tenderness
How can acute sinusitis be diagnosed?
Clinically
How is acute sinusitis managed?
Self resolving
If secondary bacterial infection
- Penicillin
- Doxycycline (NOT IN CHILDREN)
What is otitis externa?
Inflammation of the outer ear canal
How does otitis externa present?
Redness Swelling Itch Pain Increased ear wax/discharge Hearing loss (conductive - secretions or swelling block)
What are the bacterial causes of otitis externa?
Staph aureus
Pseudomonas
Proteus
What are the fungal causes of otitis externa?
Aspergillus niger
Candida albicans
How is otitis externa managed?
Topical aural toilet (i.e clean the ear of debris)
How is unresolving otitis externa managed?
Swab and culture
Fungal - topical clotrimazole
Bacterial - topical gentamicin (pseudomonas)
Which age groups typically get infectious mononucleosis/glandular fever?
Adolescents
Young adults
How does infectious mononucleosis present?
Fever Enlarged lymph nodes Sore throat/pharyngitis/tonsillitis Malaise Lethargy Palatal petechiae
What is the characteristic triad of glandular fever?
Enlarged lymph nodes
Pharyngitis
Fever
Which lymph nodes are enlarged in glandular fever?
All nodes may be enlarged but cervical nodes are often most prominent
What are the uncommon signs & symptoms of glandular fever?
Jaundice Rash Leucocytosis (inc white cells) Atypical lymphocytes Splenomegaly
Describe the onset of glandular fever
Insidious
How is glandular fever treated?
Self limiting
Rest
Avoid sport
Paracetamol (fever)
What are the possible complications of glandular fever?
Anaemia Thrombocytopenia Splenic rupture Upper airway obstruction Increased lymphoma risk (immunosupressed)
How are the complications of glandular fever managed?
Anaemia & thombocytopenia - steroids
Splenic rupture - no sport for 6 wks
Obstruction - steroids +/- intubation
What causes glandular fever?
Epstein barr virus
Describe the two different outcomes of primary infection with EPV
Infected 10 - infectious mononucleosis common
How is EPV transmitted?
Kissing
What would be done in a patient with glandular fever who wanted to return to sport?
Abdominal ultrasound to exclude splenomegaly - if no splenomegaly return to sport within a month is allowed
How can diagnosis of EPV be confirmed?
EPV IgM
Paul bunnel or monospot - heterophile antibody
Blood count + film
LFTs
What other causes of illness may mimic EPV? How can you differentiate between these?
Cytomegalovirus - no heterophile antibody
Toxoplasmosis - minimal phayngitis
HIV - diarrhoea, clues from history
How do humans become infected with toxoplasmosis?
Undercooked meat
Contact with cat litter
What are the risks of CMV and Toxoplasmosis infection?
Congenital infection + foetal damage
What are the types of herpes simplex virus?
Type 1 - oral
Type 2 - genital
How does herpes type 1 spread? When is it usually acquired?
Saliva
Childhood
What can herpes simplex type 1 cause?
Primary gingivostomatitis
Nb - this is severe reaction most cases are asymptomatic
How does primary gingivostomatitis present?
Vesicles and ulcers on the lips, hard palate and buccal mucosa
Fever
Local lymphadenopathy
How gets primary ginigvostomatitis?
Pre-school children
Which age group typically gets herpes type 2? How is it transmitted?
Adults
Sexually
How is primary gingivostomatitis (i.e herpes simplex type 1) treated?
Acyclovir
Describe latency with respect to herpes simplex virus
Primary infection –> immune system gets virus under control –> sits inactive in dorsal root ganglia –> dermatomal reactivation later in life/when immune system under stress
What is a cold sore?
Mild reactivation of herpes simplex virus
How can a cold sore be treated?
Acyclovir
Acyclovir does not prevent latency of herpes simplex. T/F
True
What is the natural progression of cold sores?
Incidence will become less and less over time
Recurrent intra-oral lesions are usually herpes simplex virus. T/F
False - oral herpetic lesions are but less common intra-orally
What is herpetic whitlow?
Herpes simplex infection of the finger
Who usually gets herpetic whitlow? How can it be prevented?
Dentists, anaesthetists
Gloves
How can herpes simplex virus infection be confirmed?
Swab –> PCR
What is a serious complication of herpes simplex infection?
Herpes simplex encephalitis
What is herpangia?
Vesicles/ulcers on the soft palate
What causes herpangia?
Coxsackie virus (enterovirus)
Which age group gets herpangia?
Children
How is herpangia diagnosed?
Clinically
Swab –> PCR
What causes hand, foot and mouth disease?
Coxsackie virus (enterovirus)
What type of outbreaks are usually caused by hand, foot and mouth?
Familial
How is hand, foot and mouth disease diagnosed?
Clinically
Swab –> PCR
What is an apthous ulcer?
Non-viral, self limiting painful ulcer which is recurrent within the mouth and surrounded by an inflammatory halo
What clinical features would point towards an apthous ulcer?
Only on mouth
No systemic disease
Childhood –> 3rd decade
Ulcers last
What systemic diseases may recurrent ulcers be associated with?
Behcets disease Coeliac IBD Reiter's triad Drug reaction Skin disease
How does behcets disease present?
Recurrent ulcers Uveitis Genital ulcers Visceral organ involvement Middle eastern patients
How does primary syphilis present?
Painless chancre (indurated ulcer) at entry site
What causes syphilis?
Treponium pallidum
Why should amoxicillin never be given to a patient with a sore throat?
Induces rash (non-allergic) in patients with infectious mononucleosis
