The conjunctiva is a loose connective tissue that covers the surface of the eyeball (bulbar conjunctiva) and reflects back upon itself to form the inner layer of the eyelid (palpebral conjunctiva). This tissue firmly adheres to the sclera at the limbus, where it meets the cornea. The accessory lacrimal glands (Krause and Wolfring), along with goblet cells, are contained within the conjunctiva and are responsible for keeping the eye lubricated.
Conjunctivitis is one of the most common nontraumatic eye complaints resulting in presentation to the emergency department (ED): 3% of all ED visits are ocular related, and conjunctivitis is responsible for approximately 30% of all eye complaints. This term describes any inflammatory process that involves the conjunctiva; however, to most patients, conjunctivitis (often called pink eye) is a diagnosis in its own right. As with any mucous membrane, infectious agents may adhere to the conjunctiva, thus overwhelming normal defense mechanisms and producing clinical symptoms of redness, discharge, irritation, and possibly photophobia.
Cellular infiltration and exudation characterize conjunctivitis on a cellular level. Classification is usually based on cause, including viral, bacterial, fungal, parasitic, toxic, chlamydial, chemical, and allergic agents. Viral etiologies are more common than bacterial, and incidence of viral conjunctivitis increases in the late fall and early spring. Classification can also be based on age of occurrence or course of disease. The etiology often can be distinguished on clinical grounds. In keratoconjunctivitis, an associated corneal involvement is present.
Several studies demonstrate that acute conjunctivitis occurs with almost equal frequency between bacterial and viral causes. Fitch et al noted that viral conjunctivitis occurs more frequently in the summer, and bacterial conjunctivitis occurs more often in the winter and spring.
Most causes of conjunctivitis are benign, with a self-limited process; however, depending on the immune status of the patient and the etiology, conjunctivitis can progress to increasingly severe and sight-threatening infections. The role of the emergency physician is to separate those few conditions requiring more vigorous treatment from the majority that can be handled satisfactorily in the ED.
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In classic presentations, patients complain of eyelids sticking together on waking. They may describe itching and burning or a gritty, foreign-body sensation. Pus sliding across the eye may distort vision, although visual acuity is normal. Photophobia is minimal. Family members with similar complaints typically present with conjunctivitis from an infectious cause. A history of a recent upper respiratory infection (URI) is typically associated with a viral cause.
In any patient with ocular complaints, perform a complete physical examination of the eye, including visual acuity, fluorescein staining, slit-lamp examination, and tonometry.
In prospective observational cohort study of 368 patients, Meltzer et al sought to identify children at low risk for bacterial conjunctivitis. The combination of 4 clinical factors was found to be independently associated with a negative conjunctival culture result, as follows:
Age 6 years or older
Presentation in April through November
No or watery discharge
No glued eye in the morning
When 3 factors were present, 76.4% of patients had a negative culture, and when 4 factors were present, 92.3% of patients had a negative culture result. 
Bilateral versus unilateral disease
Bilateral disease is typically infectious or allergic. Unilateral disease suggests toxic, chemical, mechanical, or lacrimal origin. Intraocular pressure, pupil size, and light response are all normal in unilateral disease, and ciliary flush, corneal staining, and anterior chamber reaction is absent unless a significant amount of keratitis is associated (as seen in epidemic keratoconjunctivitis [EKC]).
Bacterial conjunctivitis is characterized by acute onset, minimal pain, occasional pruritus, and, sometimes, exposure history. Ocular surface disease (eg, keratitis sicca, trichiasis, chronic blepharitis) predisposes the patient to bacterial conjunctivitis. Staphylococcal and streptococcal species are the most common pathogens.
Preauricular adenopathy sometimes occurs; chemosis (thickened, boggy conjunctiva) is common. The conjunctival discharge is copious, thick, and purulent, and the conjunctival injection is moderate or marked.
Chlamydial conjunctivitis is characterized by chronic onset, minimal pain level, occasional pruritus, and a history of sexually transmitted disease (STD). This condition tends to be chronic with exacerbation and remission. Occasional preauricular adenopathy is present, but chemosis is rare. The conjunctival discharge amount is minimal with a seropurulent quality. There is moderate conjunctival injection.
Viral conjunctivitis is characterized by acute or subacute onset, minimal pain level, and, often, exposure history. Pruritus is common, and a clear, watery discharge is typical. Occasionally, severe photophobia and foreign-body sensation occurs, usually caused by adenovirus (epidemic keratoconjunctivitis [EKC]), when associated with keratitis.
Check for preauricular adenopathy and a follicular conjunctival change, particularly on the palpebral conjunctiva. If present, the likely diagnosis is EKC. Be aware that herpes simplex and chlamydia also cause follicular conjunctivitis and preauricular adenopathy.
Preauricular adenopathy is common in EKC and herpes, whereas chemosis is variable.
The conjunctival discharge amount is moderate, stringy, or sparse, with a thin and seropurulent quality. There is moderate or marked conjunctival injection.
See Viral Conjunctivitis.
Allergic conjunctivitis is characterized by acute or subacute onset, no pain, and no exposure history. Pruritus is extremely common and the hallmark symptom of this condition. Clear, watery discharge is typical, with or without a moderate amount of mucus production.
An aggressive form of allergic conjunctivitis is vernal conjunctivitis in children and atopic conjunctivitis in adults. Vernal disease is often associated with shield corneal ulcers. Perilimbal accumulation of eosinophils (Horner-Trantas dots) typifies vernal disease. Vernal keratoconjunctivitis (VKC), usually affects young boys, tends to be bilateral, and occurs in warm weather. VKC is presumed to be a hypersensitivity to exogenous antigens and may be associated with or accompanied by keratoconus.
Preauricular adenopathy is absent; chemosis is common. The conjunctival discharge amount is moderate, stringy, or sparse, with a clear quality. There is moderate conjunctival injection.
Marginal ulcers (small white ulcers that appear on the cornea at the limbus) may indicate an allergic reaction to staphylococcal antigen.
This is a toxin-related complication of staphylococcal species that frequently cause blepharitis.
Pain, photophobia, and a foreign-body sensation are common. The ulcers are sterile and respond to topical steroids.
Giant Papillary Conjunctivitis
Giant papillary conjunctivitis resembles vernal disease. This condition occurs mainly in contact lens wearers. These patients develop a syndrome of excessive pruritus, mucous production, and increasing intolerance to contact use. The giant papillae are predominantly on the upper palpebral conjunctiva and can be seen only on lid eversion. Increased deposition may also be seen on the contact lens of the affected eye.
Prehospital and ED Management
Prehospital transport is rarely indicated for patients with conjunctivitis. More serious concerns may warrant emergency medical services (EMS) transport. Prehospital personnel, emergency physicians, and other medical personnel must be careful not to transmit this infection and should not overlook more serious comorbidity. Thorough hand washing, glove use, and using eye drops in individual or unit dose containers are necessary.
Treatment is often supportive. Artificial tears help the discomfort of keratitis and photophobia. Cold, moist compresses improve the swelling and discomfort of the lids. Antibiotic drops help prevent a secondary bacterial infection. Reserve topical corticosteroids for use by an ophthalmologist when substantial inflammation is present and herpes simplex is excluded.
Broad-spectrum antibiotics, such as Ciloxan (ciprofloxacin) or Ocuflox (ofloxacin), are good choices. Sulfacetamide is also acceptable. Aminoglycoside is toxic to epithelia and retards healing. Polytrim (trimethoprim/sulfamethoxazole) is a reasonable choice particularly in children.
Patients with gonorrheal infections, neonates with infections, and patients who are immunocompromised should be admitted for administration of intravenous antibiotics.
For treatment guidelines, see the American Academy of Ophthalmology's guidelines. 
Consult with an ophthalmologist for all serious eye complaints. Simple conjunctivitis usually can be followed up by the patient's primary care provider. Discuss with an ophthalmologist solutions to questions or equivocal diagnosis. Neisserial conjunctivitis is an ocular emergency and should be viewed as an ocular finding of systemic disease. Ophthalmologic consultation is essential.
Manage simple conjunctivitis in the ED. Transfer may be appropriate for patients with complications from chronic or gonococcal conjunctivitis when an ophthalmologist is unavailable.
Treatment with antimicrobials and symptomatic therapy is recommended for all patients initially presenting to the emergency department (ED) with simple conjunctivitis. Numerous topical antimicrobial agents may be used, including topical sulfacetamide, erythromycin, gentamicin, ciprofloxacin, or ofloxacin. Avoid neomycin-containing solutions because 8-15% of patients have hypersensitivity reactions. Instill drops every 2 hours. An ointment can be used at night or every 4-6 hours throughout the day.
Consider gonococcal conjunctivitis part of a systemic disease, thus requiring systemic treatment. Inpatient medical regimens include cefoxitin, ceftriaxone, cefotaxime, or spectinomycin. Treat all patients who have chlamydia with tetracycline, doxycycline, azithromycin, or erythromycin. Outpatient therapy is acceptable in less serious cases in which compliance can be ensured and includes intravenous ceftriaxone (50 mg/kg, not to exceed 1 g) followed by doxycycline 100 mg twice a day or erythromycin 500 mg qid. Identify and treat patients' sexualpartners.
Chlamydial conjunctivitis can be treated with doxycycline 100 mg twice a day for 10 days or azithromycin 1 g. Erythromycin can be used in pregnant patients and infants. Topical therapy with erythromycin also is recommended and may speed resolution. As with gonococcal infections, identify and treat patients' sexual partners.
Ophthalmic antibiotics are used for infectious conjunctivitis. Therapy must cover all likely pathogens in the context of the clinical setting. However, when prescribing the antibiotic, the care provider must take into account that the incidence of methicillin-resistant Staphylococcus aureus (MRSA) has continued to increase in recent years.
The US Food and Drug Administration (FDA) approved a new drug, besifloxacin, for the treatment of bacterial conjunctivitis.  Clinical studies showed that patients randomized to besifloxacin ophthalmic suspension 0.6% experienced significantly higher rates of clinical resolution and microbial eradication than patients randomized to vehicle. Besifloxacin was found to be as effective and well tolerated as moxifloxacin ophthalmic solution 0.5%.  In addition, a study by Comstock et al also showed besifloxacin ophthalmic suspension 0.6% to be safe and effective for the treatment of bacterial conjunctivitis. 
Decongestants generally have vasoconstricting effects with the ability to control pruritus. Mast cell stabilizers inhibit degranulation of sensitized mast cells following exposure to specific antigens and can aid in controlling pruritus for seasonal allergies.
Nonsteroidal anti-inflammatory agents (NSAIDs) are used for the treatment of allergic conjunctivitis. Although most NSAIDs are used primarily for their anti-inflammatory effects, they are also effective analgesics and are useful for the relief of mild to moderate pruritus. Ketorolac 0.4% has also been shown as effective in treating allergic conjunctivitis. 
Refer patients to their primary care provider for follow-up in 2-3 days to ensure they are responding to treatment. Viral conjunctivitis is usually self-limited to 10-14 days, but symptoms may persist for as many as 6 weeks.
Prescribe one of the previously mentioned antibiotics for discharged patients. For copious ocular secretions, patients may use frequent saline irrigation or artificial tears. Avoid eye patching.
Educate the patient regarding careful and frequent hand washing being necessary to reduce transmission from one eye to the other in the patient and from contacts.
During birth, risk of transmission of Gonococcus, Streptococcus, or Chlamydia to the fetus exists. Obtain maternal cervical culture results, if indicated and/or available.
Risk of chlamydial pneumonia exists. Pneumonia can occur in 10-20% of infants with chlamydial conjunctivitis as many as 6 months later. Untreated chlamydial conjunctivitis in adults can lead to conjunctival scarring.
Any of the bacterial organisms that cause conjunctivitis, particularly in a premature infant, can lead to sepsis and death. Neonates are at risk for secondary meningitis, cellulitis, and septicemia, particularly if the conjunctivitis is caused by Escherichia coli, Staphylococcus aureus, or Haemophilus influenzae.
Clinicians should be able to recognize a gonococcal infection in someone with ocular and genitourinary symptoms. Penetration of the cornea can occur within 2 days in patients with untreated Neisseria gonorrhoeae.
Infections with N meningitidis may require systemic antibiotics to prevent meningitis.
Failure to recognize herpes simplex conjunctivitis and keratitis and prescribing corticosteroids, as well as failure to consider other causes in a patient with an acutely red eye (eg, iritis, uveitis, angle-closure glaucoma, ocular ischemic syndrome, penetrating or perforating ocular injury) are also potential pitfalls.