Conjunctivitis

Question 1

What is conjunctivitis?

Answer 1

Conjunctivitis, also known as ““pink eye,”” is a common condition that involves inflammation or infection of the conjunctiva, the transparent membrane that lines the eyelid and covers the white part of the eye. This condition can be either infectious (caused by bacteria or viruses) or noninfectious (due to allergies or other irritants).
o Associated inflammation of the cornea –> keratoconjunctivitis
o Associated eye lid involvement –> blepharoconjunctivitis

Question 2

What are the causes of conjunctivitis?

Answer 2

1. The most common bacterial pathogens in infective conjunctivitis include Pneumococcus, Staphylococcus aureus, Moraxella catarrhalis, and Haemophilus influenzae
2. Viral conjunctivitis (MOST COMMON) can be caused by adenovirus, herpes simplex, Epstein-Barr, varicella zoster, molluscum contagiosum, coxsackie, and enteroviruses
3. Non-Infectious
   o Allergic
   o Mechanical/irritative/toxic
   o Immune-mediated
   o Neoplastic

Question 3

What are the risk factors for conjunctivitis?

Answer 3

use of contact lenses is a risk factor for conjunctivitis

Question 4

Summarise the epidemiology of conjunctivitis

Answer 4

• WORLDWIDE distribution
• Affects any age group
• No gender, ethnic or social preponderance

Question 5

What are the presenting symptoms of conjunctivitis?

Answer 5

• Red eye (usually generalised and often bilateral)- due to ocular hyperaemia
• Irritation, discomfort and grittiness/stickiness
• Itching (most intense in seasonal allergic conjunctivitis)
• Discharge (may be watery, mucoid, sticky or purulent depending on cause) and crust formation
  Purulent: bacteria
  Watery: viral
  Mucoid: allergic
• Photophobia (suggest corneal involvement)
• Swelling of eyelids
• Visual acuity usually unaltered.

Question 6

What signs of conjunctivitis can be found on physical examination?

Answer 6

• Conjunctival injection (i.e. blood shot eyes)
• Dilated conjunctival vessels
• Conjunctival chemosis (swell of the conjunctiva)
• Conjunctival follicles (round collections of lymphocytes appearing as small dome-shaped nodules)
• Conjunctival papillae (associated with allergic immune response)

Question 7

What investigations are used to diagnose/ monitor conjunctivits?

Answer 7

1. Rapid Adneovirus Immunoassay
2. Cell culture & Gram stain

Question 8

How is conjunctivitis managed?

Answer 8

Both viral and bacterial conjunctivitis are self-limiting and will tend to resolve in 5–10 days. Self-care measures, including regular bathing of the eyes in a medial to lateral direction, is often sufficient to control symptoms without the need for antimicrobials.
1. Viral → supportive care, topical antivirals, antihistamine drops
2. Bacterial → topical broad-spectrum antibiotics (erythromycin), topical fluoroquinolone
- Topical Abx ⇒ chloramphenicol (topical fusidic acid for pregnant women)
3. Allergic → topical antihistamines, avoid allergen, cold compress
4. Other Advice = don’t wear contact lenses, don’t share towels, school exclusion not necessary

Question 9

What complications may arise following conjunctivitis?

Answer 9

Dry eyes, keratitis, subepithelial corneal infiltrates