Microbiology Flashcards
What is conjunctivitis?
Inflammation of the conjunctiva could be due to infection, trauma or allergy
What is more common, bacterial or viral conjunctivitis?
Viral
Signs and symptoms of conjunctivitis?
Sore, red eye/s often with discharge
Purulent discharge if bacterial
Bacteria often involved in bacterial conjunctivitis?
Staph A, Strep pneumonia and haemophilus influenza
Bacteria often involved in neonatal conjunctivitis?
Staph A, Neisseria, gonorrhoea and chlamydia
Who with bacterial conjunctivitis needs referred to ophthalmology?
Neonates
Signs and symptoms of chlamydial conjunctivitis?
Often slow onset with discomfort over weeks Scanty non purulent discharge Follicular reaction (multiple slightly elevated lesions with the appearance of rice grains)
Which type of conjunctivitis can cause follicular reactions like rice grains?
Chlamydial
3 viruses that may be involved in conjunctivitis? What are the characteristics of each?
Adenovirus, herpes simplex and herpes zoster
Adeno: after a cold, red eye
HSV: Lymph nodes and cutaneous lesions
Zoster: Can effect skin and eye along different CN5 divisions
Treatment of viral conjunctivitis?
Self care measures
Should resolve
Treatment of herpetic conjunctivitis?
Aciclovir
Need to reduce risk of corneal involvement in HSV and post herpetic neuralgia in zoster
Treatment of bacterial conjunctivitis?
May resolve on own if serious or need quick resolution give chloramphenicol
Treatment of chlamydial conjunctivitis?
Topical erythromycin or oxytetracycline
Describe different preparations of chloramphenicol?
Drops must be stored in fridge
Ointment has preservative so doesn’t need fridge but can’t see well after putting it on
What is keratitis?
Corneal inflammation which can be caused by infection
What are symptoms of keratitis?
Sensation of foreign body or pain, photophobia and lacrimation
Dendritic ulcer =
Herpes simplex keratitis
Is keratitis treated in the community?
No
Must be referred to hospital due to risk of scarring
Hourly eye drops!
Why must you not use steroids if red eye in community?
Cant rule out herpes simplex keratitis and if use steroids in this you can worsen and risk perforation of the cornea
Treatment of herpes simplex keratitis?
Ganciclovir or Aciclovir hourly eye drops
2 organisms involved in contact lens associated keratitis?
Acanthomoeba or pseudomas due to water contact
Acanthomoeba keratitis is often diagnosed late and extremely painful what is treatment?
Hourly eye drops (potentially with chlorohexidine)
Pseudomonas keratitis is treated with?
Hourly oflaxacin drops
Signs and symptoms of orbital cellulitis?
Swelling Painful Proptotis Often associated with paranasal sinusitis Pyrexia
Treatment of orbital cellulitis?
Sight threatening- urgent!
Treat with ENT and broad spectrum antibiotics
Organisms in orbital cellulitis?
Staph A, Strep pneumonia and HIB
ones in URTI/ sinusitis as often spread from here
What is endophthalmitis?
Rare infection of the whole globe which is almost always post surgical
What type of infection is almost always post surgical?
Endophthalmitis
Symptoms of endophthalmitis?
Usually after a surgery
Very red eye
Very systemically unwell
Significantly reduced vision
Treatment of endophthalmitis?
Intravitreal sample then antibiotics
Systemic antibiotics are probably of little value
Amikacin, ceftazidime, vancomycin
What is chorioretinitis?
Inflammation of the choroid (pigmented vascular coat) and retina - a form of posterior uveitis
Causes of chorioretinitis?
Often congenital cause by toxoplasma or CMV, may also be associated with autoimmune disease. Can be caused by toxocara, CMV can effect those with HIV/ AIDS
Presentation of chorioretinitis?
Painless rapid blurring of vision
How does toxoplasma enter the bloodstream?
Through ingested, infected material or via maternal placenta
Describe toxoplasma and chorioretinitis
Often people are unaware they are infected and have the chorioretinitis, can lie latent for years, if active the chorioretinitis usually subsides over many weeks and only requires treatment if the chorioretinitis is sight threatening (close of adjacent to the macula or optic disc) It is treated with clindamycin/ azithromycin sometimes steroids
Describe toxocara and chorioretinitis?
Parasitic nemotode (round worm)
Often self limiting as they cannot replicate
In immunosuppressed can form granulomas which can cause irreversible visual loss
Describe how may determine the difference between orbital cellulitis and pre-septal cellulitis?
If orbital patient will have proptosis and painful eye movements.
Symptoms of blepharitis? What is it? Treatment?
Inflammation of the eyelids sore eyelids itchy eyes a gritty feeling in the eyes flakes or crusts around the roots of the eyelashes red eyes or eyelids eyelids sticking together in the morning when you wake up SYMPTOMS OFTEN COME AND GO Conservative, clean eye lids, hot packs
