Chapter 16. Conjunctivitis

A 35-year-old woman presents with 2 days of redness and tearing in her eyes (Figure 16-1). She has some thin matter in eyes, but neither eye has been glued shut when she awakens. She does not have any trouble seeing once she blinks to clear any accumulated debris. Both eyes are uncomfortable and itchy, but she is not having any severe pain. She does not wear contact lenses and has not had this problem previously. The patient was diagnosed with viral conjunctivitis and scored −1 on the clinical scoring system (see “Diagnosis”). She was instructed about eye hygiene and recovered in 3 days.

Conjunctivitis, inflammation of the membrane lining the eyelids and globe, presents with injected pink or red eye(s), eye discharge ranging from mild to purulent, eye discomfort or gritty sensation, and no vision loss. Conjunctivitis is most commonly infectious (viral or bacterial) or allergic, but can be caused by irritants. Diagnosis is clinical, based on differences in symptoms and signs.

Pink eye.

• Infectious conjunctivitis is common and often occurs in outbreaks, making the prevalence difficult to estimate.
• In the United States, the estimated annual incidence rate for bacterial conjunctivitis is 135 per 10,000 people.1
• Viral conjunctivitis is more common than bacterial conjunctivitis.
• Allergic conjunctivitis had a point prevalence of 6.4% and a lifetime prevalence of 40% in a large population study in the United States from 1988 to 1994.2

Conjunctivitis is predominately infectious (bacterial or viral) or allergic, and the most common etiologies vary by age.

• Neonatal conjunctivitis is often caused by Chlamydia trachomatis and Neisseria gonorrhoeae.3
• Children younger than 6 years are more likely to have a bacterial than viral conjunctivitis (Figure 16-2). In the United States, the most common bacterial causes are Haemophilus species and Streptococcus pneumoniae accounting for almost 90% of cases in children.4
• Children age 6 years or older are more likely to have viral or allergic causes for conjunctivitis.4 Adenovirus is the most common viral cause.

• To distinguish conjunctivitis from other causes of a red eye, ask about pain and check for vision loss. Patients with a red eye and intense pain or vision loss that does not clear with blinking are unlikely to have conjunctivitis and should undergo further evaluation.
• Always ask about contact lens use as this can be a risk factor for all types of conjunctivitis, including bacterial conjunctivitis (Figure 16-3).
• Typical clinical features of any type of conjunctivitis may include eye discharge, gritty or uncomfortable feeling, one or both pink eyes, and no vision loss. The infection usually starts in one eye, and progresses to involve the other eye days later.
• Bacterial conjunctivitis (see Figures 16-2, 16-3, and 16-4) has a more purulent discharge than viral or allergic conjunctivitis.
• A clinical scoring system has been developed to distinguish bacterial from other causes of conjunctivitis in healthy adults who did not wear contact lenses. A score of +5 to −3 is determined as follows:
  • Two glued eyes (+5); one glued eye (+2); history of conjunctivitis (−2); eye itching (−1).
  • A score of +5, +4, or +3 is useful in ruling in bacterial conjunctivitis with specificities of 100%, 94%, and 92%, respectively.
  • Scores of −1, −2, or −3 are useful in ruling out bacterial conjunctivitis with sensitivities of 98%, 98%, and 100%, respectively.5

Allergic conjunctivitis is typically bilateral and accompanied by eye itching. Giant papillary conjunctivitis is a type of allergic reaction, most commonly to soft contact lenses (Figure 16-5).

Laboratory Testing

• An in-office rapid test for adenoviral conjunctivitis (RPS Adeno Detector) has a sensitivity of 88% and a specificity of 91% compared to viral cell culture with confirmatory immunofluorescence staining.6

• Episcleritis—Segmental or diffuse inflammation of episclera (pink color), mild or no discomfort but can be tender to palpation, and no vision disturbance (see also Chapter 17, Episcleritis and Scleritis).
• Scleritis—Segmental or diffuse inflammation of sclera (dark red, purple, or blue color), severe boring eye pain often radiating to head and neck, and photophobia and vision loss (see also Chapter 17, Episcleritis and Scleritis).
• Uveitis or iritis—360-degree perilimbal injection, eye pain, photophobia, and vision loss. Frequently treated initially as conjunctivitis without resolution (see also Chapter 18, Uveitis and Iritis).
• Keratitis or corneal ulcerations—Diffuse conjunctival injection, often with miosis (constriction of pupil), eye discharge, pain, photophobia, and vision loss depending on the location of ulceration. Herpes keratitis is a diagnosis that should not be missed (Figures 16-6 and 16-7). The use of fluorescein and a UV light can help identify dendritic ulcers or other corneal damage and prompt an emergent referral to an ophthalmologist (Figure 16-7). Contact lens wearers should urgently see an ophthalmologist for keratitis.
• Acute-angle closure glaucoma—Cloudy cornea and scleral injection, eye pain with ipsilateral headache, elevated intraocular pressure, and severe vision loss (see also Chapter 19, Glaucoma).
• A foreign body in the eye can cause conjunctival injection and lead to a bacterial superinfection. If the foreign body is not easily dislodged with conservative measures, or appears to be superinfected with ulceration or leukocyte infiltrate, prompt referral to an ophthalmologist is required (Figure 16-8).

Trachoma is an eye infection caused by C. trachomatis that is rare in the United States but common in the rural areas of some developing countries. It is a leading cause of blindness in the developing world. Poverty and poor hygiene are major risk factors. Once the eye is infected, follicles can be seen on the upper tarsal conjunctiva upon eyelid eversion (Figure 16-9). Superior tarsal conjunctival scarring leads to entropion, which causes corneal scarring and ultimately blindness (Figure 16-10).

Vernal conjunctivitis is a severe recurrent form of allergic conjunctivitis that is more common in the summer (not the spring). The term vernal refers to the spring time, and therefore it is now referred to as “warm weather conjunctivitis” rather than “spring catarrh.” Giant papillae that look like a cobblestone pattern may be seen in this condition. It occurs primarily in young boys, and typically ceases to recur seasonally with age.

Hand hygiene can control the spread of infectious conjunctivitis.

Most acute conjunctival infections are viral and resolve without treatment. Following are the categories of patients who have a high probability of bacterial conjunctivitis and who are treated with topical antibiotics:

• Children younger than age 6 years.4
  • Azithromycin 1.5% ophthalmic solution twice daily for 3 days resulted in a clinical and microbiologic cure in more than 80% of children. This dosing regimen provides equivalent efficacy to 4 times a day dosing of tobramycin.7,8
• Adults who score +3 or above on the clinical scoring system for bacterial conjunctivitis.
• Studies show that more than 80% of patients show improvements with 0.3% ciprofloxacin, tobramycin, norfloxacin, or gentamicin.9,10
• Levofloxacin 0.5% is dosed 3 times a day.11
• Delayed antibiotic prescription decreased antibiotic use by nearly 50% and provided similar symptom control compared to immediate antibiotics.12

Allergic conjunctivitis can be treated with antihistamines, mast-cell stabilizers, nonsteroidal antiinflammatory agents, corticosteroids, and immunomodulatory agents.13

Referral

• Refer patients who have vision loss, copious purulent discharge (this could represent gonococcal disease, which must be cultured, and which can cause vision loss), severe pain, lack of response to therapy, or a history of herpes simplex or zoster eye disease to an ophthalmologist.
• Any patient who may need ocular steroid should be seen by an ophthalmologist. There is a severe risk for complications with the use of ocular steroids.

Good hygiene practices with washing of the hands and face with soap and water.

Routine follow-up is generally not needed if symptoms resolve in 3 to 5 days.

State health departments have no consensus on when children with conjunctivitis can return to school. A literature-based review suggests the best strategy is excluding children from school until they are asymptomatic.14

• Most adults and children older than age 6 years have a nonbacterial cause of conjunctivitis.
• Remove contact lenses until conjunctivitis has resolved.
• Avoid touching the face or rubbing the eyes and wash hands immediately afterwards.
• Do not share face towels, eye make-up, or contact lens cases.
• Inform your physician immediately if you experience eye pain or vision loss.

Patient Resources

• PubMed Health. Conjunctivitis—http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002005/.
• American Academy of Ophthalmology has patient information under For Patients and the Public at http://www.aao.org.
• American Academy of Ophthalmology. Conjunctivitis: What Is Pink Eye?—http://www.geteyesmart.org/eyesmart/diseases/conjunctivitis.cfm.
• Centers for Disease Control and Prevention has patient information in English and Spanish at http://www.cdc.gov.
• Centers for Disease Control and Prevention. Conjunctivitis (Pink Eye)—http://www.cdc.gov/conjunctivitis/index.html.
• The Livestrong foundation has auditory patient information on YouTube. Conjunctivitis Health Byte— http://www.youtube.com/watch?v=O8LkDfbLCaY; and A Healthy Byte: Pink Eye—http://www.youtube.com/watch?v=Hp28hS7XYCo&feature=relmfu.

Provider Resources

• Agency for Healthcare Research and Quality. Conjunctivitis guidelines—http://www.guideline.gov/content.aspx?id=36093.