Conjunctivitis Flashcards
(22 cards)
What is Conjunctivitis?
Conjunctivitis is the inflammation of the lining of the eyelids and eyeball caused by:
- bacteria
- viruses
- allergic or immunological reactions
- mechanical irritation
- medicines
What are the common organisms that cause Conjunctivitis>
- Pneumococcus
- Staphylococcus aureus
- Moraxella catarrhalis
- Haemophilus influenzae
What organism is the cause of persistent conjunctivitis?
Chlamydia
Which organisms are the cause of viral Conjunctivitis?
- adenovirus
- herpes simplex
- Epstein-Barr
- varicella zoster
- molluscum contagiosum
- coxsackie
- enteroviruses
How does viral Conjunctivitis spread?
Highly contagious
direct contact w
- patients
- contaminated surfaces exposed to secretions
What causes mechanichal Conjunctivitis?
chronic conjunctival irritation (especially while sleeping)
It is often caused by:
floppy eyelid syndrome, assiociated w
- obesity
- sleep apnoea
- upper eyelid laxity
- lid imbrication (upper eyelid excursion over lower eyelid).
Which drugs can cause conjunctivitis?
- glaucoma medicines
- antibiotics
- antivirals
(often contain preservatives e.g. benzalkonium chloride –> accumulates)
What type of hypersensitivity is allergic conjunctivitis?
Type 1 Hypersensitivity (IgE)
What are the 3 classifications of allergic Conjunctivitis?
- Atopic keratoconjunctivitis
- Seasonal/perennial allergic conjunctivitis
- Vernal conjunctivitis
What are the 3 classifications of bacterial Conjunctivitis?
- Gonococcal (hyperacute) bacterial conjunctivitis
- Non-gonococcal bacterial conjunctivitis
- Chlamydial conjunctivitis
What are the 3 classsifications of viral Conjunctivitis?
- Adenoviral conjunctivitis
- Herpetic conjunctivitis
- Molluscum contagiosum
What are the 3 other major classifications of Conjunctivitis (rarer)?
- Mechanical/irritative/toxic conjunctivitis
- Immune-mediated conjunctivitis
- Neoplastic
What are the risk factors for Conjunctivitis?
exposure to infected person
infection in one eye (usually viral)
Mechanical/irritative/toxic conjunctivitis
- environmental irritants
- contact lens use
- ocular prosthesis
- mechanical irritation
Allergic conjunctivitis
- allergen exposure
- Asian or Mediterranean young male (vernal)
- atopy
Viral conjunctivitis
- camps, swimming pools, military bases
What are the presenting symptoms of conjunctivitis?
Allergic
- ropy, mucoid discharge
- Itching
Viral:
- burning sensation
- watery discharge
- eyelids stuck together
- tender, pre-auricular lymphadenopathy
Bacterial
- purulent discharge
- eyelids stuck together
What can copious purulent discharge developing over 12 to 24 hours indicate?
hyperacute gonorrhoeal infection
What other pathology can bacterial conjunctivitis be associated with?
concurrent otitis media.
Hyperacute bacterial conjunctivitis is likely to be caused by Neisseria gonorrhoeae
What are the presenting symptoms?
develops over 12 to 24 hours
- copious, purulent discharge,
- eyelid swelling
- chemosis (conjunctiva swelling)
- peripheral corneal ulcers
How is bacterial conjunctivitis, hyperacute (gonorrhoeal) diagnosed?
- presence of risk factors (e.g. young, sexually active)
- Gram stain for diplocci
Bacterial conjunctivitis (chlamydial) is also sexually transmitted.
What are the presenting symptoms?
- stringy or mucous discharge
- conjunctival follicles
- corneal pannus (abnormal layer of fibrovascular tissue/granulation)
- corneal infiltrates
- Pre-auricular lymphadenopathy
What is a specific feature of viral conjunctivitis?
usually starts in one eye and spreads to the other several days later
What is the first investigation to be ordered for ?conjunctivitis ?
- rapid adenovirus immunoassay
- as adenoviruses are the most common cause
What other investigations should be considered if the 1st investigation was negative?
- cell culture
- gram stain
- PCR
