Microbiology of ENT infections Flashcards
What HSV causes oral ulcers?
Types 1 and 2
Type 1 acquired in childhood
HSV1 = oral lesions
Infections through saliva contact
What is primary gingivostomatitis?
Disease of pre-school children with a primary infection of HSV1
Systemic upset, lips, buccal mucosa, hard palate affected
Vesicles 1-2 mm
Ulcers
What will HSV2 commonly cause?
Genital ulcers
How is primary gingivostomatitis due to HSV1 treated?
Aciclovir - used for all herpes simplex infections
May take 3 weeks to recover
Where will HSV remain latent?
In the trigeminal ganglia
Will reactivate to re-infect mucosal surfaces
Will aciclovir prevent latency?
No
How many people with HSV will get clinical recurrences?
Half
How is HSV confirmed in the lab?
Swab lesion in virus transport medium to detect the viral DNA via PCR
Red cap
What is a dangerous complication of HSV infection?
Herpes simplex encephalitis
What is herpangina?
Vesicle/ ulcers on the soft palate
What causes herpangina?
Coxsackie enterovirus
What causes hand foot and mouth disease?
Coxsackie enterovirus
Diagnose by PCR test of swab in viral transport medium
What is a chancre?
Painless indurated ulcer at the site of entry of bacterium treponema pallidum (syphilis)
Most commonly genital but can be oral
What is an aphthous ulcer?
Non-viral
Self limiting
Painful ulcer on the mouth that are round or ovoid and have inflammatory halos
How long will an aphthous ulcer last?
3 weeks
What recurrent ulcers are associated with systemic disease (non-viral)?
Behcet’s disease: recurrent oral and genital ulcers, uveitis, GI, pulmonary, MSK, CV and neurological system involvement
Gluten-sensitive enteropathy or IBD: diarrhoea, wt loss
Reiter’s disease: arthritis
Drug reactions
Skin diseases: lichen planus, pemphigus vulgaris
What are the common age groups for an acute throat infection?
Children - 5-10
YA - 15-25
What is acute pharyngitis?
Inflammation of the part of the throat behind the soft palate (oropharynx)
What commonly causes a sore throat?
Common cold
Influenza
Streptococcal infection
What should you think about is there is ore throat and lethargy into the 2nd week in a patient aged 15-25?
Infectious mononucleosis via EBV
What are uncommon causes of acute pharyngitis/tonsillitis?
HIV
Gonococcal pharyngitis
Diphtheria
What are non-infectious causes of acute pharyngitis/tonsillitis?
Physical irritation - reflux, smoking, alcohol, hay-fever
LOOK FOR RED FLAGS
When should someone with a sore throat be admitted to hospital straight away?
Stridor
Resp difficulty
DO NOT attempt to examine the throat - leave to ENT surgeon
What is the natural history of a sore throat?
Self-limiting condition that will resolve within 1 week for 85% of people
What are complications of a streptococcal infection?
Otitis media (eustachian tube)
Peritonsillar abscess (quinsy)
Para-pharyngeal abscess
Mastoiditis
When should throat cancer be suspected?
Persistent sore throat for more than 3 weeks with a neck mass
Pain on swallowing or dysphagia
Red or white patches, or ulceration of the oral/pharyngeal mucosa for more than 3 weeks
Stridor
What is the recommended self care of a sore throat?
Regular analgesia - paracetamol or ibuprofen to relieve pain and fever Medicated lozenges (local anaesthetic, analgesia or antiseptic)
What can cause a bacterial sore throat?
Streptococcus pyogenes (group A beta haemolytic streptococcus) Acute follicular tonsillitis
How is streptococcus pyogenes acute follicular tonsillitis treated?
Phenoxymethylpenicillin
What are complications of streptococcus pyogenes?
Rheumatic fever - 3 weeks post sore throat; fever, arthritis and pancarditis
Glomerulonephritis - 1-3 weeks post sore throat; haematuria, albuminuria and oedema
What is the CENTOR criteria?
Tonsillar exudate
Tender anterior cervical lymph nodes
History of fever above 38
Absence of cough
What does a CENTOR score of 3 or 4 signify?
Should prescribe antibiotics
What is the Fever PAIN criteria?
Fever (last 24 hrs) Purulence Attend rapidly (w/in 3/7) v. Inflamed tonsils No cough/ coryza
What does a score of 4-5 in Fever PAIN signify?
65% risk of strep
Prescribe antibiotics
What should you do if someone on a DMARD presents with a sore throat?
FBC - neutropenia
Withhold DMARD until result is known
What can cause neutropenia?
DMARD Carbimazole - agranulocytosis Chemo Leukaemia Asplenia Aplastic anaemia HIV with a low CD4 Patient taking azathioprine post transplant
What bacterium causes diphtheria?
Corynebacterium diphtheriae (gram negative bacillus)
What is the clinical presentation of diphtheria?
Severe sore throat with a grey white membrane across the pharynx
Organism produces an exotoxin which is cardiotoxic and neurotoxic
What type of vaccine id diphtheria?
Toxoid vaccine
What is the treatment of diphtheria?
Antitoxin and supportive
Penicillin/ erythromycin (pregnant)
What is the presentation of infectious mononucleosis?
Fever Enlarged lymph nodes Sore throat, pharyngitis, tonsillitis Malaise, lethargy Jaundice/ hepatitis Rash Haematology - lymphocytosis, atypical lymphocytes in blood film Splenomegaly Palatal petechiae
What other tests should be run in someone presenting with symptoms of EBV?
HIV and CMV - very similar presentation
What are potential complications of EBV?
Anaemia Thrombocytopenia Splenic rupture - avoid contact sports Upper airway obstruction Increased risk of lymphoma
Where will the EBV remain latent?
Epithelial cells in the pharynx
What is the treatment for EBV?
Bed rest
Paracetamol for fever
Avoid contact sport for 6 weeks
Should steroids be used for viruses?
No - they make it worse
How is EBV confirmed in the lab?
EBV IgM for acute infection IgG for chronic infection Heterophile antibody - paul bunnell test, monospot test Blood count and film - lymphocytosis LFTs
What is the presentation of candida?
White patches on red, raw mucous membranes in throat/ mouth
What can cause candida?
Endogenous - post antibiotics, immunosuppressed, smokers, inhaled steroids
What is the treatment of candida?
Nystatin or fluconazole
What is acute otitis media?
An URTI involving the middle ear by extension of infection by the eustation tube
What can cause acute otitis media?
Commonly caused by a virus with a secondary bacterial infection: haemophilus influenzae, streptococcus pneumoniae, streptococcus pyogenes
When should you swab an ear?
If the ear drum perforates and thereis pus
How should middle ear infections be treated?
80% resolve in 4 days without antibiotics
1st line: amoxicillin
2nd line: erythomycin
What is malignant otitis externa?
Extension of otitis externa into the bone surrounding the ear canal (mastoid and temporal)
Without treatment is fatal as the osteomyelitis will involve the skull and meninges
What are the symptoms of malignant otitis?
Pain
Headache
More severe than clinical signs
What are the signs of malignant otitis?
Granulation tissue at bone-cartilage junction of ear canal, exposed bone in the ear canal
Facial nerve palsy
How should malignant otitis be investigated?
PV
CRP
Radiological imagine
Biopsy and culture
What are risk factors for malignant otitis?
Diabetes
Radiotherapy to head and neck
What is otitis externa?
Inflammation of outer ear canal: Redness and swelling of ear canal Itchy Sore and painful Discharge or increased ear wax Affected hearing
What bacteria can cause otitis externa?
Staph aureus
Proteus
Pseudomonas aeruginosa - swimming pools
What bacteria causes malignant otitis externa?
Pseudomonas aeruginosa
What fungus can cause otitis externa?
Aspergillus niger
Candida albicans
Culture and biopsy
What is the management of otitis externa?
Topical aural toilet
Swab to microbiology
Topical clotrimazole for aspergillus niger
Gentamicin 0.3% drops for pseudomonas
What is acute sinusitis?
Mild discomfort over frontal and maxillary sinuses due to congestion
Seen in patients with URTI
Severe pain and tenderness with purulent discharge = bacterial infection
What is the management of acute sinusitis?
Average length is 2.5 weeks
Antibiotics for severe cases over 10 days
1st line: phenoxymethylpenicillin
2nd line is doxycycline
Why should doxycycline not be prescribed in children?
Yellow tooth discolouration and dental enamel hypoplasia
What are the issues with PO ciprofloxacin?
Ruptured achilles tendon Generalised tendonitis Psychiatric symptoms Lower threshold for seizures Pseudomembranous colitis (c.diff)
