Microbiology Flashcards
viral causes of oral ulceration
herpes simplex virus (HSV)
herpangina
hand, foot and mouth disease
which type of HSV tends to cause oral lesions?
type 1
how does HSV type 1 tend to be acquired?
through saliva in childhood
cause of primary gingivostomatitis
HSV1 in childhood
describe the presentation of primary gingviostomatitis
vesicles and ulcers on lips, buccal mucosa and hard palate
can have systemic upset- fever and local lymphadenopathy
how long can it take to recover from primary gingviostomatitis
3 weeks
management of primary gingviostomatitis
acyclovir
what happens after a primary infection with HSV1?
the virus establishes latency in a sensory nerve cell and reactivation presents as a cold sore
diagnosis of HSV
swabs in a viral transport medium used to detect viral DNA by PCR
cause of herpangina
Coxsackie virus
presentation of herpangina
vesicles/ulcers on the soft palate that presents in pre-school
diagnosis of herpangina
swab in viral transport medium
cause of hand, foot and mouth disease
Coxsackie viruses
diagnosis of hand, foot and mouth disease
PCR of swab in viral transport medium
describe primary syphilis presentation
painless indurated ulcer at the site of entry of the bacterium (chancre)
cause of syphilis
bacterium
what can happen if primary syphilis is left untreated?
can progress to secondary and tertiary syphilis
cause of apthous ulcers
non-viral
stress, injury, familial, certain foods, lack of vitamins, etc.
presentation of apthous ulcers
recurring painful ulcers that are round/ovoid with inflammatory halos
confined to the mouth with absence of systemic disease
how long do apthous ulcers last?
3 weeks
begin in childhood, tend to ablate in 3rd decade
recurrent ulcers associated with systemic diseases of non-viral causes include
Behcet's disease gluten-sensitive enteropathy or IBD Reiter's disease (arthritis) drug reaction skin disease e.g. lichen planus, pemphigoid and pemphigus
define acute pharyngitis
inflammation of the throat behind the soft palate (oropharynx)
what distinguishes tonsilitis from infectious mononucleosis?
sore throat or lethargy persists into the second week, patient aged 15-25
non-infectious causes to irritation of the throat and pharynx
GORD
chronic irritation from cigarettes
alcohol
hayfever
what is a sore throat an immediate admission to hospital?
airway obstruction/ respiratory difficulty
what is the danger pathway in otitis media?
otitis media > peri-tonsillar abscess (quinsy) > parapharyngeal abscess > mastoiditis
management of a sore throat
- self care e.g. regular analgesia, lozenges, fluid, etc.
- prescribe antibiotics if needed e.g. bacterial tonsilitis (penicillin)
why do you manage strep pyogenes tonsilitis with antibiotics?
there is risk of complications
complications in strep pyogenes
rheumatic fever
glomerulonephritis
presentation of rheumatic fever
3 weeks post sore throat there is fever, arthritis and pancarditis
presentation of glomerulonephritis
1-3 weeks post sore thraot there is haematuria, albuminuria and oedema
what criteria is used to assess whether antibiotics should be given in tonsilitis?
FeverPAIN (or CENTOR)
describe the categories in the FeverPAIN criteria
fever purulence (pus on tonsils) attend rapidly (within 3 days) inflamed tonsils no cough
risk factors for strep pyogenes tonsilitis
DMARDs increased risk of neutropenia e.g. carbimazole (idiosyncratic neutropenia) chemotherapy leukaemia asplenia aplastic anaemia HIV immunosuppressed
when should phenoxymethylpenicillin be considered in tonsilitis?
FeverPAIN score is 4-5 or CENTOR score is 3-4
red flags in throat problems
- persistent sore throat, neck mass (cancer)
- sore throat with pain or dysphagia that lasts 3-4 weeks
- red or red and white patches, ulceration or swelling of oral/pharyngeal mucosa for more than 3 weeks
- stridor/respiratory difficulty
presentation of diphtheria
sore throat
grey-white membrane across the pharynx
what does the organism in diphtheria produce?
potent exotoxin which is cardiotoxic and neurotoxic
what kind of vaccine is used to manage diphtheria?
toxoid vaccine
management of diphtheria
antitoxin
support penicillin/erythromycin
presentation of infectious mononucleosis
fever enlarged lymph nodes sore throat pharyngitis tonsillitis malaise lethargy jaundice/hepatitis rash leucocytosis presence of atypical lymphocytes splenomegaly palatal petechiae
complications of infectious mononucleosis
anaemia, thrombocytopenia
splenic rupture
upper airway obstruction
increased risk of lymphoma, especially in immunosuppressed
cause of infectious mononucleosis
EBV
diagnosis of infectious mononucleosis
EBV IgM
heterophile antibody- Paul Bunnell test or Monospot test
blood count and film
LFTs
management of infectious mononucleosis
bed rest
paracetamol
avoid sport
corticosteroids in complicated cases
other causes of a similar illness to EBV
CMV
toxoplasmosis
primary HIV
presentation of candida
white patches on red
raw mucous membranes in throat/mouth
causes of candida
endogenous substances e.g. post-antibiotics, immunosuppressants, smoking and ICS
when should candida be investigated?
if reccurent
management of candida
nystatin
fluconazole
define acute otitis media
URTI involving the middle ear by extension of infection up eustachian tube
presentation of acute otitis media
otalgia
cause of acute otitis media
most commonly viral but can have secondary bacterial (H, influenzae, strep pneumonia and strep pyogenes)
diagnosis of acute otitis media
swab of eardrum if perforates (otherwise samples cannot be obtained)
management of acute otitis media
most resolve without antibiotics
first line=amoxicillin
second line= erythromycin
define malignant otitis externa
this is extension of otitis externa into the bone surrounding the ear canal e.g. mastoid or temporal (osteomyelitis can progress to skull and meninges)
what happens if malignant otitis externa is not treated?
it is fatal
presentation of malignant otitis externa
pain
headache
granulation tissue at bone-cartilage junction of ear canal, exposed bone in the ear canal
facial nerve palsy (drooping on side of the lesion)
investigations for malignant otitis externa
plasma viscosity/CRP
radiological imaging
biopsy
culture (pseudomonas aeruginosa)
risk factors for malignant otitis externa
diabetes
radiotherapy of head and neck
define otitis externa
inflammation of the outer ear canal
presentation of otitis externa
redness swelling of skin in canal itchy pain discharge/earwax if canal becomes blocked then hearing can be affected
bacterial causes of otitis externa
staph aureus
proteus spp
pseudomonas aeruginosa
fungal causes of otitis externa
aspergillus niger
candida albicans
management of otitis externa
swabs for unresponsive/severe cases
topical clotrimazole for aspergillus
gentamicin drops
presentation of acute sinusitis
discomfort over frontal and maxillary sinuses due to congestion
URTI
if bacterial then purulent discharge and severe pain
antibiotic use in acute sinusitis
only is severe/deteriorating cases of >10 days duration
- 1st line= phenoxymethylpenicillin
- 2nd line= doxycycline (NOT in children)
