The diagnosis of viral conjunctivitis is based on clinical and laboratory signs. Correct and early identification of etiology allows appropriate treatment and the avoidance of longer-term complications.

Patients with viral conjunctivitis present with sudden onset foreign body sensation, red eyes, itching, light sensitivity, burning, and watery discharge. Whereas with bacterial conjunctivitis, patients present with all the above symptoms, but with mucopurulent discharge and mattering of the eyelids upon waking. Those presenting with viral conjunctivitis usually have a recent history of upper respiratory tract infection or recent contact with a sick individual. Visual acuity is usually at or near their baseline vision. The cornea can have subepithelial infiltrates that can decrease the vision and cause light sensitivity. The conjunctiva is injected (red) and can also be edematous. In some cases, a membrane or pseudomembrane can be appreciated in the tarsal conjunctiva. These are sheets of fibrin-rich exudates that are devoid of blood or lymphatic vessels. True membranes can lead to the development of subepithelial fibrosis and symblepharon, and also bleed heavily on removal.[20] Follicles, small, dome-shaped nodules without a prominent central vessel, can be seen on the palpebral conjunctiva. The majority of viral conjunctivitis patients will have follicles present, but the presence of papillae does not rule out a viral etiology.[21] Palpation of the preauricular lymph nodes may reveal a reactive lymph node that is tender to the touch and will help differentiate viral conjunctivitis versus bacterial. With HSV, vesicles may appear on the face or eyelids and vision may be affected. Corneal involvement may occur. With herpes zoster, there is a linear dermatomal pattern of vesicles. The conjunctiva is often red with a mucopurulent discharge.

Fever, malaise, fatigue, presence of enlarged lymph nodes, and other constitutional signs help to differentiate viral conjunctivitis from other causes. Anisocoria and photophobia are associated with serious eye conditions including anterior uveitis, keratitis, and scleritis.[22] Systemic diseases associated with conjunctivitis include skin and mucous membrane diseases (acne rosacea, ichthyosis, xeroderma pigmentosum), collagen vascular diseases (systemic lupus erythematosus,  rheumatoid arthritis, Sjogren's disease, granulomatosis with polyangiitis), and autoimmunity (graft versus host disease, Steven-Johnson syndrome, and ocular cicatricial pemphigoid). 

Laboratory testing is typically not indicated unless the symptoms are not resolving and infection last longer than 4 weeks. Laboratory testing can be indicated in certain situations such as a suspected chlamydial infection in a newborn, an immune-compromised patient, excessive amounts of discharge, or suspected gonorrhea co-infection. In the office, physicians can run tests to positively identify adenovirus with a specificity and sensitivity of 89% and 94%, respectively. However, ophthalmologists usually can make the diagnosis clinically with confirmational additional testing.[23] 

Regarding adenovirus testing, the gold standard has traditionally been cell culture because once the virus is isolated, the diagnosis is definitive and the characterization of the virus can be undertaken.[24] Disadvantages include cost and increased time associated with cell culture-based testing. The mainstay of viral conjunctivitis testing in the developed world is the detection of viral DNA by polymerase chain reaction (PCR). PCR for adenovirus has been shown to be 93% sensitive and 97.3% specific from conjunctival swabs, with similar values, found for HSV diagnosis.[24] A recent development has been the creation of a rapid detection testing platform for adenovirus, the AdenoPlus assay (Rapid Pathogen Screening Inc., Sarasota, Florida, USA). This is a swift office-based test designed to detect 53 serotypes of adenovirus and provide a result within 10 minutes.[25] Studies have demonstrated high specificity values of 92% to 98% in detecting adenoviral conjunctivitis. [26][27][28] However, the test has lower sensitivity reported compared with PCR analysis.[26][27][28] Rapid detection testing can be more useful in the future once viral conjunctivitis treatments reach the clinical setting.[29]

Treatment for viral conjunctivitis is aimed at symptomatic relief and not to eradicate the self-limiting viral infection. The resolution of conjunctivitis can take up to 3 weeks. Treatment includes using artificial tears for lubrication four times a day or up to ten times a day with preservative-free tears. Cool compresses with a wet washcloth to the periocular area may provide symptomatic relief. Preventing the spread of infection to the other eye or other people requires the patient to practice good hand hygiene with frequent washing, avoidance of sharing towels or linens, and avoiding touching their eyes. A person is thought to shed the virus while their eyes are red and tearing.

If a membrane or pseudomembrane is present, it can be peeled at the slit lamp to improve patient comfort and prevent any scar formation from occurring. These membranes can either be peeled with a jeweler forceps or a cotton swab soaked with topical anesthetic. Topical steroids can help with the resolution of symptoms. However, they can also cause the shedding of the virus to last longer. Patients should be informed that they are highly contagious and should refrain from work or school until their symptoms resolve. While using steroids, they may still shed the virus without the visual symptoms that would indicate that they have an infection. Steroids should be reserved for patients with decreased vision due to their subepithelial infiltrates or severe conjunctival injection causing more the expected discomfort.[30][31]

The use of povidone-iodine, a non-specific disinfectant, is a promising new treatment for adenoviral conjunctivitis.[25] This is an inexpensive and widely available antiseptic solution which is used as part of the aseptic preparation for ocular surgery. It is able to kill extracellular organisms but has no effect intracellularly. It does not induce drug resistance because its mechanism of action is not immunologically dependent. A single dose of 2.5% povidone-iodine in infants with adenoviral conjunctivitis resulted in a reduction in symptom severity and reduced recovery time without significant side effects.[32]

Topical corticosteroids alone are contraindicated in epithelial herpes simplex keratitis and are associated with prolonged viral shedding and infection.[29] When used in combination with an anti-infective, corticosteroids have demonstrated good tolerability and efficacy in treating the inflammatory and infectious components of conjunctivitis.[33][34] 

While the most common causes of conjunctivitis are viral or bacterial and due to allergic reactions, there are other causes of conjunctivitis that should be considered when treatment does not improve symptoms. Uveitis is a local autoimmune reaction that causes the eye to become inflamed and is commonly mistaken for conjunctivitis. Uveitis can be a local reaction that is idiopathic or a manifestation of a systemic autoimmune disease such as rheumatoid arthritis, lupus, or ankylosis spondylitis. Systemic autoimmune disease such Sjogren syndrome or Stevens-Johnson syndrome can also mimic conjunctivitis by presenting with conjunctival erythema and discharge. 

A systemic workup should be initiated if any of these diseases are suspected. The most life or sight-threatening masqueraders of conjunctivitis include cavernous carotid fistula, orbital cellulitis, and orbital hemorrhage. In cavernous carotid fistulas, an abnormal communication between the arterial and venous circulation form causing vasodilation of the venous system. Subsequently, the fistula can cause rupture and hemorrhage, leading to irreversible damage to the eye and/or death. Due to venostasis, the ophthalmic vein dilates and causes congestion of the episcleral vessels mimicking conjunctivitis. Proptosis and a pulsatile globe can help differentiate between a fistula and conjunctivitis. Orbital cellulitis is an infection posterior to the septum and involves the orbital contents. Patients present with similar symptoms of conjunctivitis, but will also have pain with eye movements or even restricted eye movements. Lastly, an orbital hemorrhage is an ophthalmic emergency. The cause is mostly traumatic, but it is possible to have a spontaneous hemorrhage, especially in patients on anticoagulants, that present with proptosis, tight eyelids, and erythema of the conjunctiva.

The majority of cases of virus conjunctivitis resolve on their own. In rare cases, chronic infection may occur. Most cases resolve within 14-30 days. In some patients, photophobia, diminished vision and glare may be a problem.

• Punctate keratitis
• Bacterial superinfection
• Conjunctival scarring
• Corneal ulceration
• Chronic infection

The vast majority of viral conjunctivitis is caused by adenoviruses, and frequent hand washing, disinfection, and isolation of conjunctivitis patients can reduce further community transmission. There is no single treatment modality for viral conjunctivitis. Symptom relief with artificial tears, cold-compresses, and antihistamines can be effective. Antibiotic drops can potentially increase bacterial resistance and membranes or pseudomembrane require removal to reduce discomfort and scarring. The use of topical corticosteroids is indicated in select cases in the presence of membrane formation and subepithelial infiltration associated with photophobia and decreased vision. 

The majority of patients with viral conjunctivitis are first managed by the primary care giver, pediatrician or nurse practitioner. Even though viral conjunctivitis is a benign condition, it is contagious can be easily transmitted to others. The key is patient education.

Patients need to be educated that the condition is harmless and will resolve spontaneously. Hand washing should be emphasized since the infection is highly contagious. Parents and teachers should be educated on the importance of isolation in school to prevent epidemics. All patients with viral conjunctivitis who wear contact lenses should be told to refrain from wearing them until the symptoms have subsided.

The emergency department should have a special room for patients presenting with conjunctivitis to prevent spread to other patients. signs should be placed on the doors about not shaking hands and washing hands at every opportunity. Once the patient has been seen, he or she must be individually escorted out of the clinic to avoid contact with other patients. Many lawsuits have resulted in the past after patients in the emergency room acquired conjunctivitis from infected individuals, sitting in the same location.

While long-term sequelae are rare, chronic viral conjunctivitis can lead to a poor quality of life. Most cases take 1-4 weeks to recover without treatment. The morbidity is rare but can include corneal ulceration and punctate keratitis.  Follow up with an ophthalmologist is recommended to ensure that no complications have occurred.[35][36] (Level V)