Microbiology- ENT infections Flashcards
What is the most common bacterial cause of sore throat?
Strep. pyogenes
What do Group A streps look like?
Gram positive chains, showing Beta (complete) haemolysis on blood agar
What are potential acute and long term complications of strep throat?
Acute: peritonsillar abscess (quinsy), sinusitis, otitis media, scarlet fever.
Late: rheumatic fever (3 weeks post infection), glomerulonephritis (1-3 weeks post op)
What are the three main features of rheumatic fever?
Fever, arthritis, pericarditis
How does diphtheria present?
Sore throat (severe), lymphadenopathy, grey/white membrane across the pharynx
What is the causative agent in diphtheria?
Cornyebacterium diptheriae
What is the treatment for oral thrush?
Nystatin
What is the diphtheria toxin made from?
C. diptheriae toxin
How is diphtheria treated?
Antitoxin + erythromycin/penicillin (see antibiotic man)
How does acute otitis media often occur?
URTI which has extended up the Eustachian tube
Acute otitis media is often viral, with secondary bacterial infection. Which organisms are often implicated?
H. influenzae, strep pneumoniae, strep pyogenes
How is acute otitis media treated?
80% resolve without antibiotics. Amoxicillin is first line
How does acute sinusitis present?
Severe pain and tenderness over the sinuses; purulent nasal discharge
When should antibiotics be used in treating acute sinusitis, and which antibiotic should be avoided in children?
Reserve for serious/deteriorating cases >10 days duration. Penicillin is first line, doxycycline is 2nd but should be avoided in children
What is otitis externa?
Inflammation of the outer ear
How does otitis externa present?
Red, painful, itchy and swollen external ear canal. May be discharge or increased wax which may impair hearing
Which organisms commonly cause otitis externa?
Staph aureus, Proteus spp, pseudomonas aeruginosa, aspergillus and candida
How is otitis externa managed?
Topical aural toilet; swab if unresponsive, culture and direct antibiotic therapy to sensitivities
What is the classic triad of symptoms in infectious mononucleosis?
Fever, lymphadenopathy and pharyngitis
Which other symptoms/signs may be seen in infectious mononucleosis?
Malaise and lethargy; jaundice, rash, splenomegaly, palatal petechiae
What causes infectious mononucleosis?
EBV infection of B cells
List some potential complications of mono.
Anaemia, thrombocytopenia, splenic rupture, upper airway obstruction, lymphoma (esp. in immunocompromised)
When might corticosteroids be useful in treating mono?
In cases of upper airway obstruction or haemolytic anaemia
What lab tests can be used to confirm mono?
Blood film- atypical lymphocytes, lymphocytosis. Heterophil antibody tests. EBV IgM
What are important differential diagnoses to consider in mono?
Cytomegalovirus, toxoplasmosis, HIV seroconversion illness
How does primary gingivostomatitis present?
In childhood; herpetic lesions on lips, buccal mucosa, hard palate; fever; lymphadenopathy
Which virus causes primary gingivostomatitis?
Herpes simplex virus Type 1
Where does HSV1 become latent?
Sensory nerve roots
Where does herpes simplex encephalitis most frequently occur?
Temporal lobe
How are cold sores treated?
Aciclovir
Which virus causes herpangina and hand foot and mouth?
Coxsackie enterovirus
How is the cause of viral oral ulceration confirmed?
Swab in viral transport medium; viral PCR
