Diagnosis → Ophthalmology

Conjunctivitis

Etiology

Cause [s4r]

• Viral: Adenovirus (most common), HSV, VZV, Molluscum contagiosum, enterovirus

• Bacterial: S. aureus, S. pneumoniae, H. influenzae, S. pneumoniae, Moraxella spp

• Sexually transmitted or neonates: Chlamydia trachomatis, Neisseria gonorrhoeae

• Allergic: Seasonal/perennial allergic conjunctivitis; atopic keratoconjunctivitis

• Toxic/chemical/medicamentosa: Irritants; topical medication/preservative toxicity

• Mechanical/ocular surface disease: Contact lens, giant papillary conjunctivitis, blepharoconjunctivitis, keratoconjunctivitis sicca, foreign body, mucus fishing

• Immunological: Pemphigoid, SJS/TEN, GVHD, vasculitis, Reiter syndrome

• Metabolic disease: Vitamin A deficiency, porphyria and Richner-Hanhart syndrome

• Masquerades (neoplastic): Sebaceous carcinoma, ocular surface squamous neoplasia, melanoma; ligneous conjunctivitis

Pathophysiology

1. Trigger at conjunctival surface

   • Infection

   • Allergen

   • Irritant/medicament

   • Mechanical friction

   • Autoimmune basement-membrane targeting

2. Inflammatory response

   • Conjunctival vasodilation → conjunctival injection/red eye

   • Exudation/mucus production → watery vs mucopurulent discharge

3. Viral: Bilateral affection and enlarged preauricular lymph node

4. Allergic: Bilateral, watery/stringy mucus with pruritus

5. Toxic: Exposure history

6. Mechanical: Contact lens, foreign body

7. Masquerade: Unilateral chronic/nonresponsive, tumor, lash loss, recurrent “blepharitis” → consider neoplasia (sebaceous carcinoma)

Risk factors

• Contact lens wear

• Close-contact exposure/daycare/school outbreaks (adenovirus)

• Atopy/asthma/eczema (allergic, atopic keratoconjunctivitis)

• Sexual activity/new partner (chlamydial/gonococcal)

• Immunocompromise

• Chronic topical medicaments

• Systemic immune disease (OMMP, SJS/TEN, GVHD, vasculitis)

Complications

• Corneal involvement: Keratitis, corneal ulceration, scarring, vision loss

• Membranous conjunctivitis

• Progressive conjunctival scarring/symblepharon/fornix foreshortening

• Neonatal systemic disease association

Epidemiology

Incidence per 100.000 [s4r][igv][f68]

Default

Approach

Clinical approach [s4r]

• Visual acuity

• Corneal staining/defect

• Anterior chamber reaction

• Severe purulent discharge

• Culture/Gram stain from eyelid

• Chlamydia PCR

• Adenovirus rapid antigen test

• Biopsy: Suspected OMMP or neoplasia

Diagnostic criteria

1. Red eye + conjunctival injection

2. Preserved vision

3. No evidence of keratitis/uveitis/acute angle closure/orbital cellulitis

Treatment

1. Usually self-limiting [s4r]

2. Supportive care: Lubricants/artificial tears, cold compresses

3. Remove contact lenses

4. Avoid routine topical antibiotics and topical corticosteroids

5. Exclude red-eye emergencies

6. Allergic: Allergen avoidance and topical antihistamine

7. Viral: Consider antiviral therapy with topical ganciclovir 0.15% gel 1 drop 5 times/day

8. Bacterial: Symptomatic treatment, short course of broad-spectrum topical antibiotic

9. Gonococcal conjunctivitis: Ceftriaxone 1 g IM

Differential diagnoses

Blepharitis, Cancer, Chalazion, Corneal abrasion, Corneal ulcer, Episcleritis, Foreign body, Glaucoma, Hordeolum, Iridocyclitis, Keratitis, Keratoconjunctivitis sicca, Periorbital cellulitis, Pterygium, Scleritis, Sjogren syndrome, Stevens-Johnson syndrome, Subconjunctival hemorrhage, Toxic epidermal necrolysis