Conjunctivitis (OP) Flashcards
Define conjunctivitis.
Inflammation of conjunctiva (mucus membrane lining inside of eyelids and sclera)
What are some specific sub-categories of conjunctivitis? (2)
- keratoconjunctivitis - associated inflammation of cornea
- blepharoconjunctivitis - associated eyelid involvement
What are the main types of conjunctivitis? (3)
- bacterial conjunctivitis (more common in children)
- viral conjunctivitis (more common in adults)
- allergic conjunctivitis
What are some causes of conjunctivitis? (7)
- bacteria (more common in children)
- viruses (more common in adults)
- allergic reactions
- mechanical irritation
- medicines
- immune-mediated
- neoplastic
Which bacteria commonly cause conjunctivitis? (4)
- S. aureus
- H. influenzae
- Pneumococcus
- Moraxella catarrhalis
Which viruses commonly cause conjunctivitis? (7)
- adenovirus
- enteroviruses
- HSV
- EBV
- VZV
- Molluscum contagiosum
- Coxsackie
How does conjunctivitis generally present?
Irritated red eye with watery/purulent discharge
What are the clinical features of conjunctivitis? (6)
- red eye (due to ocular hyperaemia)
- discharge + crust formation
- itching (most intense in seasonal allergic conjunctivitis)
- eyelid swelling
- eyelids stuck together in morning
- photophobia (corneal involvement)
What might you see on examination in conjunctivitis? (7)
- bloodshot eyes
- dilated conjunctival vessels
- conjunctival chemosis (swelling)
- conjunctival follicles (round collections of lymphocytes appearing as small dome-shaped nodules)
- conjunctival papillae (allergic)
- superficial punctate keratopathy
- palpable pre-auricular lymph nodes (bacterial, absent in viral)
Is visual acuity affected in conjunctivitis?
No
What can the nature of the red eye in conjunctivitis tell us about the cause?
- unilateral = bacterial
- bilateral = allergic
What can the nature of the discharge in conjunctivitis tell us about the cause?
- bacterial - purulent (pus)
- viral - watery
- allergic - mucoid, sticky
What do we see in bacterial conjunctivitis?
- unilateral redness + thick purulent discharge (yellow crusting)
- eyes may be stuck together in morning
What do we see in viral conjunctivitis?
- bilateral (begins unilateral) redness + clear watery discharge
- recent URTI
What do we see in allergic conjunctivitis?
- bilateral redness + sticky, mucoid discharge
- itchiness
- may be seasonal or due to specific allergens (patient will have Hx of atopy - eczema, asthma, hayfever)
What are some risk factors for conjunctivitis? (7)
- exposure to infected person
- allergen exposure
- concurrent infection
- contact lens use
- topical medications - glaucoma meds, Abx, antivirals
- rosacea
- Hx atopy (eczema, asthma, hayfever)
What are the main two investigations done for conjunctivitis?
- rapid adenovirus immunoassay
- cell culture & gram stain
What are some differential diagnoses for conjunctivitis? (6)
- dry eyes (chronic, minimal discharge)
- blepharitis (chronic, minimal discharge)
- episcleritis (unilateral)
- scleritis (severe ocular pain on movement and redness, reduced visual acuity may be present)
- keratitis (intense pain, discharge, photophobia, lacrimation)
- uveitis (pain, red, no discharge, photophobia)
How do we manage allergic conjunctivitis?
- mild - supportive (avoid allergen, cold compresses, artificial tears)
- moderate - mast cell stabiliser +/- topical antihistamine (sodium cromoglicate ophthalmic)
- severe - add topical corticosteroid (prednisolone) or ciclosporin, immunotherapy
How do we manage bacterial conjunctivitis?
- mild/mod - topical broad-spectrum Abx (chloramphenicol or topic fusidic acid for pregnant women)
- mod/severe - topical fluoroquinolone (ciprofloxacin)
- hyperacute (gonococcal) - topical and systemic Abx (ceftriaxone, doxycycline/azithromycin, bacitracin)
How do we manage viral conjunctivitis?
Topical antivirals, antihistamine drops, supportive care:
- adenovirus - topical antihistamine (epinastine), topical corticosteroid, topical ganciclovir
- HSV - observation +/- topical/oral antivirals
- VZV - refer to opthalmologist
- Molluscum contagiosum - observation and removal of lesions
How do we manage chlamydial conjunctivitis?
Azithromycin
How do we manage conjunctivitis due to contact lens?
Topical corticosteroids with fluoroquinolone, do not wear contacts during episode
How do we manage mechanical conjunctivitis?
Supportive measures +/- surgery (full-thickness horizontal shortening of upper eyelid)
What is some general advice for conjunctivitis? (2)
- do not wear contact lenses
- do not share towels
What are some complications of conjunctivitis? (4)
- dry eyes
- keratitis
- subepithelial corneal infiltrates
- lacrimal drainage problems
Describe the prognosis of conjunctivitis.
Mostly self-limiting
