Microbiology Flashcards
when is bacterial conjunctivitis a worry?
in neonates
causative organisms of neonate bacterial conjunctivitis
staph aureus
neisseria gonorrhoea
chlamydia trachomatis
causative organisms in other age groups outside neonates of bacterial conjunctivitis
staph aureus
strep pneumonia
H. influenza (especially children)
presentation of bacterial conjunctivitis
morning crust (yellow discharge)
difficulty opening eye
rapid onset
gritty eye (BUZZWORD)
diagnosis of bacterial conjunctivitis
swab
management of bacterial conjunctivitis
topical antibiotic e.g. chloramphenicol qds
fusidic acid for staph aureus
gentamicin for gram -ve
what does chloramphenicol treat?
most bacteria except pseudomonas aeruginosa
two ways of delivering chloramphenicol?
drops (need to be stored in the fridge)
ointment (difficult to see through)
when should you avoid chloramphenicol?
history of aplastic anaemia
action of chloramphenicol
inhibits peptidyl transferase enzymes (stops bacterial protein being made)
what is chloramphenicol bactericidal to?
strep
haemophilus
what is chloramphenicol bacteriostatic to?
staph
side effects of chloramphenicol
allergy
irreversible aplastic anaemia
grey baby syndrome (neonatal liver cannot cope)
what gram negatives is gentamicin used against in bacterial conjunctivitis?
coliforms
pseudomonas
what can neisseria gonorrhoeae additionally present with in bacterial conjunctivitis?
lid swelling
globe tenderness
conjunctival chemosis
this can lead to corneal ulceration and perforation (URGENT referral)
causes of viral conjunctivitis
adenovirus (pink eye)
herpes simplex
herpes zoster
presentation of viral conjunctivitis
sudden onset and rapidly progressive can be bilateral due to contagious and spreading to other eye watery pain pre-auricular nodes
what hygiene should be exercised in viral conjunctivitis?
strict hand hygiene
no sharing of towels
this is because it is highly contagious
diagnosis of viral conjunctivitis
swab
presentation of adenoviral conjunctivitis
red and inflamed eye
watery discharge (bacterial is stickier)
often history of URTI
management of adenoviral conjunctivitis
antibiotics only used if risk of secondary infection
presentation of herpes simplex conjunctivitis
vesicles on conjunctiva and eyelids
describe herpes zoster conjunctivitis
reactivation of V1, V2 and/or V3 (herpes zoster ophthalmicus)
management of herpes zoster conjunctivitis
acyclovir to minimise risk of post-hepatic neuralgia
management of viral conjunctivitis
topical lubricant e.g. hypromellose (aim for preservative free as if the patient is using this 4-6 times a day then there is risk of irritation)
acyclovir for herpes zoster
presentation of chlamydial conjunctivitis
chronic history low grade red eye follicles on inner eyelid (grains of rice) discharge pre-auricular lymphadenopathy
when to consider chlamydial conjunctivis
unresponsive to treatment
bilateral in young adults (contact tracing required)
management of chlamydial conjunctivitis
topical oxytetracycline as risk of subtarsal scarring (+ oral azithromycin if genital infection)
what to think in follicular conjunctivitis?
chlamydial conjunctivitis
presentation of allergic conjunctivitis
itch
watery
bilateral
management of allergic conjunctivitis
allergen avoidance
topical antihistamines
once stabilised use mast cell stabilisers e.g. sodium cromoglycate
define episcleritis
inflammation of the thin vascular sheet between the conjunctiva and sclera
who is episcleritis common in?
patients with collagen-vascular disease such as RA, sarcoidosis and IBD
management of episcleritis
NSAIDs
topical lubricants