Conjunctivitis resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief:

Overview

Conjunctivitis is the most common eye infection causing dilation of conjunctival blood vessels and results in inflammation. The most common cause of conjunctivitis is infection of which viral infections are the commonest cause, followed by bacterial. The non-infection forms are allergic, mechanical, toxic and neoplastic. Among noninfectious conjunctivitis, the allergic form is more common. Infectious conjunctivitis can be presented with red eye, foreign body sensation, itching, light sensitivity, burning, and watery discharge in viral conjunctivitis and mucopurulent discharge in bacterial form. Regarding the onset and severity of clinical symptoms, conjunctivitis is classified as acute, chronic, and recurrent. Most cases of infectious conjunctivitis are considered as acute conjunctivitis. Allergic conjunctivitis can be chronic while it can be present with acute exacerbations related to seasonal factors or contact lens use. It is important to differentiate conjunctivitis from other sight-threatening eye diseases that have similar clinical presentation.

Causes

Life Threatening Causes

Most cases of conjunctivitis are relatively mild and will not cause eye damage of any sort. However, if it left untreated it can lead to sight-treathening complications including:

• keratitis
• keratoconjunctivitis

Viral conjunctivitis

• Adenoviruses are the most common cause of viral conjunctivitis
• Herpes simplex virus (HSV)
• Varicella zoster virus (VZV)
• Picornaviruses

Bacterial conjunctivitis

• Staphylococcus aureus
• Haemophilus influenza
• Streptococcus pneumoniae
• Moraxella catarrhalis

Diagnosis

Some initial diagnosis should be excluded for which physicians should manage patients by a systematic approach.

Suspected acute conjunctivitis (<4 weeks duration)

Associated with pain, blurred vision, photophobia

Yes

No

Ophthalmology referral

Any discharge

Yes

No

Hyperpurulent

Mucopurulent

Serous

Ophthalmology referral

Gonococcal conjunctivitis

Bacterial conjunctivitis

Itiching

Ophthalmology referral

Yes

No

Allergic conjunctivitis

Viral conjunctivitis

Differential diagnosis

Differentail diagnosis	Manifestation	Examination findings
Blepharitis	Burning and foreign-body sensation, symptoms worse with prolonged reading or watching	Bilateral redness
Uveitis	Photophobia, pain, blurred vision	Decreased vision, poorly reacting pupils, constant eye pain radiating to temple and brow, red eye
Angle closure glaucoma	Headache, nausea, vomiting, ocular pain, decreased vision, light sensitivity	Firm eye on palpation, ocular redness, steamy cornea
Endophthalmitis	Severe pain, photophobia	Red eye, pus in the anterior chamber, history of eye surgery or ocular trauma
Scleritis	Decreased vision, moderate to severe pain	Redness, bluish sclera
Subconjunctival hemorrhage	foreign-body sensation and tearing or be asymptomatic	Blood under the conjunctival membrane

Treatment

Medical therapy for conjunctivitis

Category	Epidemiology	Type of discharge	Cause	Treatment
Viral conjunctivitis	80% of all acute conjunctivitis	Serous	Adenovirus in 65% of cases	Cold compress Artificial tears Antihistamines
HSV	1.3-4.8% of all acute conjunctivitis	Variable	Herpes simplex virus	Topical acyclovir 1 drop 9 ×/d for 7-10 days
Acute bacterial conjunctivitis	18.3%-57% of all acute conjunctivitis	Mucopurulent	S aureus, S epidermidis, H influenzae S pneumoniae	Aminoglycosides Gentamicin Ointment: 4 ×/d for 1 wk Solution: 1-2 drops 4 ×/d for 1 wk Fluoroquinolones Ciprofloxacin ointment: 3 ×/d for 1 wk Solution: 1-2 drops 4 ×/d for 1 w
Allergic conjunctivitis	Up to 40% of population may be affected	Serous or mucoid	Pollens	Topical antihistamines Azelastine 0.05%: 1 drop 2 ×/d Topical mast cell inhibitors Cromolyn sodium 4%: 1-2 drops every 4-6 h

Do's

• In assessment of a person presenting with red eye, serious causes (such as acute glaucoma, keratitis, iritis and trauma) must be excluded.
• Urgent referral to ophthalmology should be arranged if the person has:
  • A red flag indicating a serious cause of red eye
  • Suspected gonococcal or chlamydial conjunctivitis
  • Suspected periorbital or orbital cellulitis
  • Had recent intraocular surgery
  • Conjunctivitis associated with a severe systemic condition or is immunocompromised
  • Corneal involvement
  • Possible herpes infection
• Reassuring the person that most cases are self-limiting.
• Advising self-care measures such as cleaning the eyelids, cool compresses, lubricating drops or artificial tears and avoidance of contact lenses.
• In most cases of bacterial conjunctivitis, observation can be the only option because they often resolve spontaneously and no treatment is necessary. However, using topical antibiotics is are effective in reducing the duration of conjunctivitis.
• Topical antihistamines and mast cell stabilizers in allergic conjunctivitis is recommended.
• In cases of severely purulent conjunctivitis bacterial culture is useful.

Don'ts

• People with weaker immune systems such as those with diabetes and people who don’t wash their hands before inserting or removing contact lenses are more at risk of bacterial conjunctivitis.
• Patients with any form of conjunctivitis should refrain wearing contact lenses until the conjunctivitis has completely cleared up.
• Both types of infectious conjunctivitis are very contagious and easily spread. It is important to avoid contacting with other or sharing equipments with other people to help prevent spreading the infection.

References

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