Overview of Conjunctivitis

Any source of inflammation can cause lacrimation or discharge and diffuse conjunctival vascular dilation. Discharge may cause the eyes to crust overnight. Thick discharge may blur vision, but once discharge is cleared, visual acuity should be unaffected.

Itching and watery discharge predominate in allergic conjunctivitis. Chemosis and papillary hyperplasia also suggest allergic conjunctivitis Allergic Conjunctivitis Allergic conjunctivitis is an acute, intermittent, or chronic conjunctival inflammation usually caused by airborne allergens. Symptoms include itching, lacrimation, discharge, and conjunctival... read more . Irritation or foreign body sensation, photophobia, and discharge suggest infectious viral conjunctivitis Viral Conjunctivitis Viral conjunctivitis is a highly contagious acute conjunctival infection usually caused by an adenovirus. Symptoms include irritation, photophobia, and watery discharge. Diagnosis is clinical... read more ; purulent discharge suggests bacterial conjunctivitis Acute Bacterial Conjunctivitis Acute conjunctivitis can be caused by numerous bacteria. Symptoms are hyperemia, lacrimation, irritation, and discharge. Diagnosis is clinical. Treatment is with topical antibiotics, augmented... read more . Unusually severe eye pain suggests scleritis Scleritis Scleritis is a severe, destructive, vision-threatening inflammation involving the deep episclera and sclera. Symptoms are moderate to marked pain, hyperemia of the globe, lacrimation, and photophobia... read more .

Usually, diagnosis of conjunctivitis is made by history and examination (see table ), usually including slit-lamp Slit-lamp examination The eye can be examined with routine equipment, including a standard ophthalmoscope; thorough examination requires special equipment and evaluation by an ophthalmologist. History includes location... read more examination with fluorescein staining of the cornea and, if glaucoma Overview of Glaucoma Glaucomas are a group of eye disorders characterized by progressive optic nerve damage in which an important part is a relative increase in intraocular pressure (IOP) that can lead to irreversible... read more is suspected, measurement of intraocular pressure. In order to prevent transmitting infection to other patients and to staff, meticulous disinfection of equipment that touches the eye is particularly important after examination of patients who could have conjunctivitis.

Other disorders can cause a red eye Red Eye Red eye refers to a red appearance of the opened eye, reflecting dilation of the superficial ocular vessels. Dilation of superficial ocular vessels can result from Infection Allergy Inflammation... read more . Deep pain in the affected eye when a light is shone in the unaffected eye (true photophobia) does not occur in uncomplicated conjunctivitis and suggests a disorder of the cornea or anterior uvea. Circumcorneal conjunctival hyperemia (sometimes described as ciliary flush) is caused by dilated, fine, straight, deep vessels that radiate out 1 to 3 mm from the limbus, without significant hyperemia of the bulbar and tarsal conjunctivae. Ciliary flush occurs with uveitis Overview of Uveitis Uveitis is defined as inflammation of the uveal tract—the iris, ciliary body, and choroid. However, the retina and fluid within the anterior chamber and vitreous are often involved as well.... read more , acute glaucoma Overview of Glaucoma Glaucomas are a group of eye disorders characterized by progressive optic nerve damage in which an important part is a relative increase in intraocular pressure (IOP) that can lead to irreversible... read more , and some types of keratitis (see Corneal Disorders Introduction to Corneal Disorders Symptoms that suggest corneal involvement (eg, rather than simple conjunctivitis) include unilateral involvement, pain (foreign body sensation and ache—not just a gritty sensation), particularly... read more ) but not with uncomplicated conjunctivitis.

The cause of conjunctivitis is suggested by clinical findings. However, cultures are indicated for patients with severe symptoms, immunocompromise, a vulnerable eye (eg, after a corneal transplant, in exophthalmos Proptosis This photo shows a woman's slightly bulging left eye (proptosis), caused by a meningioma. Proptosis is protrusion of the eyeball. Exophthalmos means the same thing, and this term is usually... read more due to Graves disease Etiology ), or poor response to initial therapy.

Clinical differentiation between viral and bacterial infectious conjunctivitis is not highly accurate. However, if the history and examination strongly suggest viral conjunctivitis, withholding antibiotics initially is appropriate. Antibiotics can be prescribed later if the clinical picture changes or if symptoms persist.

Clinicians must take the following steps to avoid transmitting conjunctivitis, which is most often highly contagious and spread by droplets, fomites, and hand-to-eye inoculation:

Patients should do the following:

Eyes should be kept free of discharge and should not be patched. Small children with conjunctivitis should be kept home from school to avoid spreading the infection. Cool washcloths applied to the eyes may help relieve local burning and itching. Antimicrobials are used for certain infections.

Acute bacterial conjunctivitis Acute Bacterial Conjunctivitis Acute conjunctivitis can be caused by numerous bacteria. Symptoms are hyperemia, lacrimation, irritation, and discharge. Diagnosis is clinical. Treatment is with topical antibiotics, augmented... read more is typically treated with antibiotics (topical for causes except gonococcal and chlamydial). Gonococcal conjunctivitis and adult inclusion conjunctivitis Adult Inclusion Conjunctivitis Adult inclusion conjunctivitis is caused by sexually transmitted Chlamydia trachomatis. Symptoms include chronic unilateral hyperemia and mucopurulent discharge. Diagnosis is clinical... read more require systemic antibiotics.

Viral conjunctivitis is typically self-limited, but severe cases sometimes require topical corticosteroids.

Allergic conjunctivitis is treated with topical antihistamines, nonsteroidal anti-inflammatory drugs, mast cell stabilizers, or a combination. Topical corticosteroids or cyclosporine are used for recalcitrant cases. Oral antihistamines may be helpful for patients with other allergic symptoms (eg, rhinorrhea).