DIFFERENTIATE THE VARIOUS FORMS OF CONJUNCTIVITIS

THE COMMON forms of conjunctivitis are allergic conjunctivitis, viral conjunctivitis and bacterial conjunctivitis. Their signs and symptoms can present in similar fashions and have overlap, causing doctor confusion.

ALLERGIC CONJUNCTIVITIS

This typically presents bilaterally and can range from acute to seasonal and chronic allergic conjunctivitis. Allergen exposure to the ocular surface occurs, and the inflammatory cascade begins with mast cell degranulation, causing the release of inflammatory mediators, such as histamine.

ALLERGIC SIGNS

• Chemosis
• Conjunctival injection
• Eyelid edema
• Inflammation
• Papillae
• Tearing

ALLERGIC SYMPTOMS

• Burning
• Decreased contact lens wear time and reduced comfort
• Excessive tearing
• Itching (usually the primary clinical symptom)
• Rhinitis

TESTING

Consider point-of-care allergy testing to identify the allergen, and refer the patient to a local allergist for a full work-up. [In eye care, that’s Doctor’s Allergy Formula system (Bausch + Lomb).]

TREATMENT

The four available options:

• Eye wash/artificial tears. These lubricate, wash away and dilute allergens from the ocular surface and tear film. Prescribe “when needed” use.
• Cool compress. These help give symptomatic relief in mild allergic reactions. Prescribe “when needed” use.
• Prescription anti-histamines/mast cell stabilizers. These block H1 and H2 receptors and decrease the amount of allergens that bind to mast cells, causing mast cell degranulation, which reduces the release of other allergic mediators. Most are dosed q.i.d. or b.i.d. as needed or long-term.
• Topical steroids. These reduce inflammation. Prescribe these b.i.d. to q.i.d., depending on severity, for one to two weeks.

BACTERIAL CONJUNCTIVITIS

Common forms of bacterial conjunctivitis are caused by Haemophilus influenza in children and Streptococcus pneumoniae in adults. Other causes: MRSA, Staphylococcus epidermis and Moraxella catarrhalis. Bacterial conjunctivitis usually presents unilaterally, though it may present bilaterally, making clinicians suspect allergic conjunctivitis.

BACTERIAL SIGNS

• Conjunctival injection
• Mucopurulent discharge
• Possible pediatric concomitant respiratory and ear infections.
• Tearing

BACTERIAL SYMPTOMS

• Irritation

TESTING

Consider culturing or referring for a culture in severe or chronic presentations.

TREATMENT

Once a specific strain of bacteria is confirmed with growth by a lab, if necessary, replace the antibiotic you prescribed while waiting for lab results, with a more appropriate and efficacious antibiotic. The use of antibiotics can vary, but q.i.d. for seven to 10 days is common.

VIRAL CONJUNCTIVITIS

Viral conjunctivitis can be caused by several different strains of viruses with adenovirus accounting for about 60% of infectious conjunctivitis cases, reports May 2007’s Optometry. Classic adenovirus, also called epidemic keratoconjunctivitis, is a common cause of infectious conjunctivitis in adults and children.

Adenoviruses are resilient to disinfection, and they can live for weeks on inanimate objects, such as doorknobs. Widespread and epidemic cases are at largely populated venues, such as schools.

Typically, viral conjunctivitis begins in one eye and then spreads to the fellow eye in three to seven days. If an early diagnosis or proper treatment isn’t carried out, corneal infiltrates can develop around one-week after the initial viral replication begins, causing symptoms. (See “Viral Symptoms.”) Delayed corneal infiltrate treatment can cause permanent decreased vision.

VIRAL SIGNS

• Conjunctival edema
• Conjunctival injection
• Hyperemia
• Inflammation
• Lid edema
• Palpable ipsilateral preauricular or submandibular lymphadenopathy
• Peri-orbital edema
• Sub-epithelial infiltrates
• Superior petechial hemorrhages

VIRAL SYMPTOMS

• Acute tearing
• Burning
• Decreased vision
• Irritation
• Foreign-body sensation
• Lid edema
• Photophobia
• Serous discharge

TESTING

In-office point-of-care testing can confirm a viral etiology, help you determine a proper treatment plan, educate the patient or parent whether it’s infectious and decrease unnecessary sick days.

TREATMENT

This falls under palliative and off-label. Palliative consists of cool compresses, artificial tears and OTC vasoconstrictors and antihistamines, as needed for 10 to 14 days. Off-label is betadine, topical ganciclovir and topical steroids.

With betadine, a topical anesthetic is placed on the eye. Next, a topical NSAID or topical steroid (q.i.d. for seven to 10 days, depending on severity) is placed on the eye for patient comfort, followed by four to five drops of 5% betadine for about 60 seconds. Then, an irrigating eye wash is employed to remove residual betadine.

Topical ganciclovir is effective against adenovirus, significantly reducing both the duration and incidence of subepithelial infiltrates with a quick recovery time. Prescribe use q.i.d. for seven to 10 days, depending on severity.

ARRIVING AT AN ANSWER

Types of conjunctivitis have some overlapping signs and symptoms that may lead to confusion and improper diagnosis. Be aware of specific signs and symptoms that differentiate the conditions from one another, to have better clinical success in diagnosing and treating these conditions. OM

DR. JOHNSTON practices at Georgia Eye Partners. He focuses on ocular surface disease and has extensive experience in co-managing cataract and refractive surgery patients. He is consultant and speaker for with Abbott, Alcon, Allergan, BioTissue and Shire. Email him at drj@gaeyepartners.com.