Conjunctivitis

Conjunctival inflammation of the the inner eyelids (the tarsal conjunctiva) and the sclera (the “white of the eye”, which is the bulbar conjunctiva). Conjunctivitis can be secondary to a variety of causes, which we divide into infectious and non-infectious.

• Prominent feature is purulent “mucus” consistency discharge (yellow, green, or white).
• Unilateral or bilateral in distribution.
• 7 – 10 day course.
• Highly contagious.
• Typically occurs in the Winter/Spring (December to April).
• Key bacteria include -
• Adults: Staphylococcus aureus (and less often Streptococcus pneumoniae, Haemophilus influenzae).
• Children: Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis.
• Critically ill: Pseudomonas aeruginosa
• Newborns (via oculogenital transmission): Neisseria gonorrheae and Chlamydia trachomatis
• Contact Wearers: Pseudomonas aeruginosa is a notable cause. As well, be aware that the risk of Acanthamoeba keratitis (a vision-threatening infection) is increased by contact use.

• Chlamydia trachomatis, the worldwide leading infectious cause of blindness, is a keratoconjunctivitis secondary to recurrent Chlamydia trachomatis infection. The infection typically occurs in children in endemic areas via direct or indirect transmission of ocular or nasal secretions (the microorganism collects on a person’s fingers, on an inanimate object (fomite), or on a fly and is transmitted to another individual’s eyes).
• Note that trachoma manifests as active conjunctivitis (active trachoma) and ultimately can result in conjunctival scarring (cicatricial disease), which is secondary to recurrent infection and a type 4 hypersensitivity response (cell-mediated delayed hypersensitivity).
• Note that Chlamydia trachomatis produces 3 forms of eye infection (trachoma is just one of them). The other two are:
• Neonatal conjunctivitis occurs when a newborn (in the first 15 days of life) is infected from vagina of an infected mother during delivery.
• Adult inclusion conjunctivitis occurs in the setting of concomitant genitourinary tract infection.

• Adenoviral conjunctivitis is the prominent cause (~ 75% of cases).
• Typically, part of an adenovirus infection with a upper respiratory infectious prodrome.
• Copious, watery, mucoserous discharge with a “gritty” feeling in one eye and then the other eye becomes symptomatic within 1-2 days.
• Highly contagious (transmissible).
• Patients may report purulent discharge but this is usually actually crusting of serous discharge overnight giving a more purulent appearance in the morning.
• Ocular viral conjunctivitis can be part of herpes infections, including:
• Herpes simplex virus epithelial keratitis (HSV keratitis) can occur during initial infection or recurrent infection. Key pathological finding: “multiple small branching epithelial dendrites on the corneal surface”.
• Herpes zoster ophthalmicus, which is shingles in the V1 distribution, which is typically extremely painful and can lead to corneal scarring.

• Airbone allergens induce a type I IGE-mediated hypersensitivity response.
• Bilateral pink (more-so than red) appearance.
• “Velvety thickening” and Giant papillae on the inner eyelid, giving a cobblestone appearance.
• Burning, itching, irritation, worsens with eye rubbing.
• Associated allergy history.
• Forms of allergic conjunctivitis:
• Seasonal conjunctivitis due to seasonal allergen.
• Atopic keratoconjunctivitis is a chronic (perennial), severe form.
• Vernal keratoconjunctivitis is a chronic, severe form in a select climate: warm, dry, subtropical (eg, the Mediterranean).
• Giant papillary conjunctivitis in contact wearers.

• Irritant-induced.
• Typically, self-limited.

• Azari, Amir A., and Neal P. Barney. “Conjunctivitis: A Systematic Review of Diagnosis and Treatment.” JAMA 310, no. 16 (October 23, 2013): 1721–29. https://doi.org/10.1001/jama.2013.280318.

• Chen, Yu-Yen, Su-Hsun Liu, Ulugbek Nurmatov, Onno Cp van Schayck, and Irene C. Kuo. “Antibiotics versus Placebo for Acute Bacterial Conjunctivitis.” The Cochrane Database of Systematic Reviews 3, no. 3 (March 13, 2023): CD001211. https://doi.org/10.1002/14651858.CD001211.pub4.

• “Conjunctivitis - EyeWiki.” Accessed July 8, 2024. https://eyewiki.aao.org/Conjunctivitis#Viral_conjunctivitis.

• Epling, John. “Bacterial Conjunctivitis.” BMJ Clinical Evidence 2012 (February 20, 2012): 0704.

• Ibrahim, Youhanna W., David L. Boase, and Ian A. Cree. “Factors Affecting the Epidemiology of Acanthamoeba Keratitis.” Ophthalmic

Epidemiology 14, no. 2 (January 1, 2007): 53–60. https://doi.org/10.1080/09286580600920281.

• Mishori, Ranit, Erica L. McCLASKEY, and Vince J. Winklerprins. “Chlamydia Trachomatis Infections: Screening, Diagnosis, and Management.” American Family Physician 86, no. 12 (December 15, 2012): 1127–32.

Conjunctivitis (side view) Conjunctivitis (front view)