IPN 2022 October

Conjunctivitis: Infectious and Non-Infectious

Conjunctivitis, also known as red or pink eye, is an eye conditions caused by infection or allergies. We recently spoke to Theresa Lowry Lehnen (PhD), Clinical Nurse Specialist and Associate Lecturer South East Technological University for a further insight into the infectious and non-infectious diagnosis of this very common and prevalent condition.

An interview with Theresa Lowry- Lehnen (PhD), CNS, GPN, RNP, South East Technological University

Conjunctivitis, also known as red or pink eye, is an eye conditions caused by infection or allergies. We recently spoke to Theresa Lowry Lehnen (PhD), Clinical Nurse Specialist and Associate Lecturer South East Technological University for a further insight into the infectious and non-infectious diagnosis of this very common and prevalent condition.

Conjunctivitis can be acute or chronic and infectious or noninfectious. Viruses and bacteria are the most common infectious causes. Theresa explains, “Non-infectious conjunctivitis includes allergic, toxic, and cicatricial conjunctivitis, as well as inflammation secondary to immune-mediated diseases and neoplastic processes. 2 Prevalence of conjunctivitis varies according to the underlying cause, which may be influenced by the patient’s age, as well as the season of the year.”

Viral conjunctivitis is the most common cause of infectious conjunctivitis both overall and in the adult population and is more prevalent in summer. Theresa points out that the signs and symptoms of viral conjunctivitis at presentation are variable - it usually does not require treatment, she says.

“Bacterial conjunctivitis is the second most common cause of infectious conjunctivitis, with most uncomplicated cases resolving in 1 to 2 weeks. Bacterial conjunctivitis is responsible for the majority of cases in children and occurs more frequently in winter. The majority of bacterial conjunctivitis cases are self-limiting and no treatment is necessary in uncomplicated cases. However, conjunctivitis caused by chlamydia or gonorrhoea and conjunctivitis in contact lens wearers should be treated with antibiotics. Allergic conjunctivitis occurs most often in spring and summer. Treatment with antihistamines and mast cell stabilisers usually alleviates the symptoms.” 1 Treatment with antihistamines and mast cell stabilizers alleviates the symptoms of allergic conjunctivitis.

Symptoms

The classic symptoms of the three most common types of conjunctivitis are: 2

Viral: symptoms of itching and tearing, history of recent upper respiratory tract infection, watery discharge, inferior palpebral conjunctival follicles, tender pre-auricular lymphadenopathy.

Bacterial: symptoms of redness and foreign body sensation, morning matting of the eyes, white-yellow purulent or mucopurulent discharge, conjunctival papillae, infrequently pre-auricular lymphadenopathy.

Allergic: symptoms of itching or burning, history of allergies/atopy, watery discharge, oedematous eyelids, conjunctival papillae, no pre-auricular lymphadenopathy.

Diagnosis

“A focused history and ocular examination are important for making a diagnosis and appropriate decisions about the treatment and management of conjunctivitis,” says Theresa. Labs and cultures are rarely indicated to confirm the diagnosis of conjunctivitis. Cultures and cytology are usually reserved for cases of recurrent conjunctivitis, those resistant to treatment, suspected gonococcal or chlamydial infection, suspected infectious neonatal conjunctivitis, and adults presenting with severe purulent discharge. 1, 2

“Ocular history includes timing of onset, prodromal symptoms, unilateral or bilateral eye involvement, associated symptoms, previous treatment and response, past episodes, type of discharge, and presence of pain, itching, eyelid characteristics, periorbital involvement, vision changes, photophobia, and corneal opacity. 2 The ocular exam should focus on visual acuity, extraocular motility, visual fields, discharge type, shape, size and response of pupil, the presence of proptosis, corneal opacity, foreign body assessment, tonometry, and eyelid swelling. 2

“Eye discharge type and ocular symptoms can help determine the cause. A purulent or mucopurulent discharge is often due to bacterial conjunctivitis, a watery discharge is more characteristic of viral conjunctivitis and itching is associated with allergic conjunctivitis. However,

clinical presentation is often nonspecific and relying on the type of discharge and patient symptoms does not always lead to an accurate diagnosis. 1

“Similar to redness and discharge, other common signs and symptoms of conjunctivitis are nonspecific and can make determining the underlying cause more difficult.” For example, she told us, itching is historically correlated with allergic conjunctivitis and while in the context of watery discharge and a history of atopy this is likely the case, one study found that 58% of patients with culture-positive bacterial conjunctivitis also reported itchy eyes. 2

Papillae, a nonspecific finding in conjunctivitis can be present in both infectious and noninfectious conjunctivitis. Theresa adds, “Papillae, small elevations usually under the superior tarsal conjunctival, with central vessels are often present in bacterial conjunctivitis, allergic conjunctivitis, and contact lens intolerance. Papillae in chronic allergic conjunctivitis can lead to a cobblestone appearance of the conjunctiva. 2 While also non-specific, the presence of follicles, in conjunction with other findings, can help differentiate the aetiology of conjunctivitis. Follicles are small elevated yellow-white lesions found at the junction of the palpebral and bulbar conjunctiva and are a lymphocytic response often present in chlamydial and adenoviral conjunctivitis. 2

“Differential diagnosis can include glaucoma; iritis; keratitis; episcleritis; scleritis; pterygium; corneal ulcer; corneal abrasion; corneal foreign body; subconjunctival

haemorrhage; blepharitis; hordeolum; chalazion; contact lens over use and dry eye. Other signs and symptoms that can point to diagnosis other than conjunctivitis include localised redness, redness not including the entire conjunctiva, ciliary flush, elevated intraocular pressure, vision loss, moderate to severe pain, hypopyon, hyphema, pupil asymmetry, decreased pupil response, and trouble opening the eye or keeping it open. 2 It is important to differentiate conjunctivitis from other causes of “red eye” associated with severe sight- or life-threatening consequences.” Theresa also notes that while presentations can often overlap, a systematic approach including a thorough history and ocular exam should safely out rule acute sightthreatening diagnoses and identify the likely cause of conjunctivitis. 7

Viral Conjunctivitis

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Viruses are responsible for up to 80% of all cases of acute conjunctivitis. She continues, “Clinical accuracy in diagnosing viral conjunctivitis is less than 50% compared with laboratory confirmation and many cases

are misdiagnosed as bacterial conjunctivitis. Between 65% and 90% of cases of viral conjunctivitis are caused by adenoviruses, which can produce pharyngoconjunctival fever and epidemic keratoconjunctivitis, two of the common clinical entities associated with viral conjunctivitis.

“Pharyngo-conjunctival fever (PCF) caused by HAdV types 3, 4 and 7 is usually characterised by the presence of fever, pharyngitis, periauricular lymphadenopathy, and acute follicular conjunctivitis. Additional ocular surface findings include oedema, hyperaemia, and petechial haemorrhages of the conjunctiva as a result of interaction between proinflammatory cytokines and conjunctival vasculature.

“This condition is self-limited, often resolving spontaneously in two–three weeks without any treatment. 6 The most severe ocular manifestation of adenoviral infection is epidemic keratoconjunctivitis (EKC) which affects both the conjunctiva and cornea, leaving behind long-lasting and permanent ocular surface changes and visual disturbances. Serotypes, 8, 19, 37 and less frequently serotype 4 were believed to be associated with EKC, but more recently, HAdV-D53 and HAdV-D54 have been identified in several outbreaks and thought to be responsible for the majority of EKC cases. 6 Ocular manifestations of EKC include conjunctival discharge, follicular conjunctivitis, corneal sub epithelial infiltrates (SEI), corneal scarring, development of conjunctival membranes and pseudo membranes and symblepharon formation. 6

Lymphadenopathy occurs in up to 50% of viral conjunctivitis cases and is more prevalent in viral conjunctivitis compared with bacterial conjunctivitis. Treatment with antihistamines and mast cell stabilizers alleviates the symptoms of allergic conjunctivitis.

Viral conjunctivitis secondary to adenoviruses is highly contagious and spreads through direct contact example via contaminated fingers, medical instruments, swimming pool water, or personal items.” Incubation and communicability are estimated to be 5 to 12 days and 10 to 14 days, respectively. 1

“Conjunctivitis caused by the herpes simplex virus is usually unilateral. The discharge is thin and watery, and accompanying vesicular eyelid lesions may occur. Topical and oral antivirals are recommended, however, topical corticosteroids should be avoided because they potentiate the virus and may cause harm. 1

“Herpes zoster virus, responsible for shingles, can involve ocular tissue, especially if the first and second branches of the trigeminal nerve are involved. Eyelids are the most common site of ocular involvement, followed by the conjunctiva. Corneal complication and uveitis may occur. Patients with suspected eyelid or eye involvement or those presenting with Hutchinson sign (vesicles at the tip of the nose, which has high correlations with corneal involvement) should be referred for a thorough ophthalmic evaluation. Treatment usually consists of a combination of oral antivirals and topical steroids.” 1

Bacterial Conjunctivitis

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Bacterial conjunctivitis can be contracted from infected individuals or result from abnormal proliferation of the conjunctival flora.

Contaminated fingers, oculogenital spread, and contaminated fomites are common routes of transmission. Certain conditions such as compromised tear production, disruption of the natural epithelial barrier, abnormality of adnexal structures, trauma, and immunosuppressed status can predispose to bacterial conjunctivitis. Bacterial conjunctivitis is much more common in children than adults, and the pathogens responsible vary depending on the age group. The most common pathogens responsible for bacterial conjunctivitis in adults are staphylococcal species, followed by Streptococcus pneumoniae and Haemophilus influenzae. In children, the condition is often caused by H influenzae, S pneumoniae, and Moraxella catarrhalis. The infection usually lasts 7 to 10 days. 1, 2

“Hyperacute bacterial conjunctivitis presents with decreased vision and a severe copious purulent discharge. There is often accompanying eyelid swelling, eye pain on palpation, and preauricular adenopathy. It is often caused by Neisseria gonorrhoeae and carries a high risk for corneal involvement and subsequent corneal perforation. Treatment

for hyperacute conjunctivitis secondary to N gonorrhoea is intramuscular ceftriaxone, and concurrent chlamydial infection should be managed accordingly. Conjunctival hyperemia, mucopurulent discharge, and lymphoid follicle formation are hallmarks of chlamydial conjunctivitis. Discharge is often purulent or mucopurulent, however, patients often present with mild symptoms for weeks to months.

“Chlamydial conjunctivitis is often acquired via oculogenital spread or other intimate contact with infected individuals and in new-borns the eyes can be infected after vaginal delivery by infected mothers. Treatment with systemic antibiotics such as oral azithromycin and doxycycline is efficacious. Patients and their sexual partners must be treated and a coinfection with gonorrhoea

Chronic bacterial conjunctivitis is used to describe any conjunctivitis lasting more than 4 weeks. Staphylococcus aureus, Moraxellalacunata, and enteric bacteria are the most common causes. Ophthalmologic consultation should be sought for management.

Signs and symptoms include red eye, purulent or mucopurulent discharge, and chemosis.

Theresa adds that incubation and communicability are estimated to be 1 to 7 days and 2 to 7 days, respectively.

Bilateral mattering and adherence of the eyelids, lack of itching, and no history of conjunctivitis are strong positive predictors of bacterial conjunctivitis,” she says. “Severe purulent discharge should always be cultured and gonococcal conjunctivitis should be considered. Conjunctivitis not responding to standard antibiotic therapy in sexually active patients warrants a chlamydial evaluation. The possibility of bacterial keratitis is high in contact lens wearers, who should be treated with topical antibiotics and referred to an ophthalmologist. A patient wearing contact lenses should be asked to remove them.” 1, 6

Allergic conjunctivitis

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Allergic conjunctivitis is the

inflammatory response of the conjunctiva to allergens such as pollen, animal fur and other environmental antigens. Redness and itching are the most consistent symptoms. 2

“Ocular allergic conditions can be classified into three main categories: IgE-mediated reactions, including seasonal allergic conjunctivitis (SAC) and perennial allergic conjunctivitis (PAC); combined IgE and non-IgEmediated reactions, including VKC and AKC; and non-IgE-mediated reactions, including giant papillary conjunctivitis (GPC) and contact dermatoconjunctivitis (CDC). 6

“Treatment involves avoidance of the offending antigen and the use of saline solution or artificial tears to dilute and remove the allergens. Topical decongestants, antihistamines, mast cell stabilisers, nonsteroidal anti-inflammatory drugs and corticosteroids may be indicated. Steroids must be used judiciously and only when indicated.” 1, 7

Treatment and Management

Theresa concludes by adding that effective management of conjunctivitis includes timely diagnosis, appropriate differentiation of the various aetiologies, and appropriate treatment.

“Most acute bacterial conjunctivitis infections are self-limiting and do not require topical antibiotics. Acute bacterial conjunctivitis is usually unilateral with yellow-white mucopurulent discharge and symptoms usually resolve within 5-7 days without treatment. If topical antibiotics are considered necessary a delayed prescription for 3 days should be considered to see if symptoms resolve with self-care and without antibiotic eye drops. 7

“Antibiotic ointments last longer than drops, however they tend to interfere with vision. Chloramphenicol is not recommended in pregnancy or breastfeeding. In 2021 the Summary of Product Characteristics for Chloromycetin ® 0.5% Redi-Drops was updated to contra-indicate use of the drops in children under 2 years. This is due to a risk of toxicity from boron. This excipient is not present in the ointment formulation and the contra-indication applies to the drops only.” 7

“Antibiotic drops are indicated for complicated bacterial conjunctivitis, in conjunctivitis caused by gonorrhoea or chlamydia, and in bacterial conjunctivitis in contact lens wearers. 5 The recommended treatment for gonococcal

HSE (2021). Conjunctivitis: Antibiotic Prescribing. Available at: https://www.hse.ie/eng/services/ list/2/gp/antibiotic-prescribing/conditions-and-treatments/skin-soft-tissue/conjuncitivitis/ conjuncitivitis-ophthalmology.html

conjunctivitis is ceftriaxone 1gm IM, and it is also recommended to treat for concurrent chlamydial infection with 1gm azithromycin orally. The neonatal dosing for gonococcal conjunctivitis is 25 to 50mg/kg ceftriaxone IV/IM with a max dose of 125mg, with 20mg/ kg azithromycin PO once daily for three days. 2

“Viral conjunctivitis due to adenoviruses is usually selflimiting,

and treatment should target symptomatic relief including cold compresses and saline solution or artificial tears. 2

“Herpes simplex keratitis requires antiviral therapy such as aciclovir or ganciclovir and the patient should be reviewed by an ophthalmologists to monitor for complications. 2 Treatment of herpes zoster conjunctivitis includes a combination of oral antivirals and

topical steroids, however, steroids should only be part of therapy in consultation with ophthalmology. Antiviral doses differ from those used for herpes simplex and consist of oral acyclovir 800mg five times a day, oral famciclovir 500mg TDS, or oral valacyclovir 1g TDS for 7 to 10 days.” 3, 4

Topical corticosteroids are not recommended for cases of bacterial or viral conjunctivitis,

except for herpes zoster, as they can prolong the condition or potentiate the infection, resulting in complications including corneal damage and blindness. 1, 2

“Treatment for allergic conjunctivitis consists of allergen avoidance, artificial tears, cold compresses, and a wide range of topical agents. Topical agents include topical antihistamines alone or in combination with vasoconstrictors, topical mast cell inhibitors and topical glucocorticoids for refractory symptoms. Oral antihistamines can also be used in moderate to severe cases of allergic conjunctivitis. 1, 2

“Any patient with moderate to severe pain, vision loss, corneal involvement, severe purulent discharge, conjunctival scarring, recurrent episodes, lack of response to therapy, or herpes simplex keratitis should receive a prompt referral to an ophthalmologist. In addition, patients requiring steroids, contact lens wearers, and those with photophobia should also be referred to an ophthalmologist. 2

“Viral and bacterial conjunctivitis can spread by direct contact and have high transmission rates. Patient education is important to prevent transmission and the importance of hand hygiene should be highlighted.

Caution with steroids/ antibioticsteroid combination drops

“Steroids should be used with caution. Steroid drops or combination drops containing steroids should not be used routinely. Topical steroids are associated with cataract formation and can cause an increase in eye pressure, leading to glaucoma. 1 if an undiagnosed corneal ulcer secondary to herpes, bacteria, or fungus is present, steroids can also worsen the condition, leading to corneal erosion and blindness. 1

Complications

“Complications of acute conjunctivitis are rare. However, patients who fail to show improvement should be referred to an ophthalmologist for further evaluation. Patients with HZV conjunctivitis are at the highest risk of complications including corneal complications and uveitis, and should always see an ophthalmologist for close re-evaluation. Patients with N. gonorrhoea are also at high risk for corneal involvement and secondary corneal perforation and should be treated appropriately,” 2 she concludes.

References available on request