Conjunctivitis

Excerpt

Conjunctivitis is a common cause of eye redness and, subsequently, a common complaint in the emergency department, urgent care clinics, and primary care clinics. People of any age, demographic, or socioeconomic status can be affected. More than 80% of all acute cases are generally diagnosed by non-ophthalmologists, such as internists, primary care providers, pediatricians, and nurse practitioners. In the United States, this imparts a substantial economic burden on the healthcare system, costing about $857 million annually. While conjunctivitis is typically a temporary condition that does not often lead to vision loss, ruling out other potential sight-threatening causes of red-eye during evaluation is crucial.

The conjunctiva is the transparent, lubricating mucous membrane covering the eye’s outer surface and comprises 2 parts: the bulbar conjunctiva that covers the globe and the tarsal conjunctiva that lines the eyelid’s inner surface.

Conjunctivitis refers to the inflammation of the conjunctival tissue, engorgement of the blood vessels, pain, and ocular discharge, and is classified as acute or chronic and infectious or noninfectious. Acute conjunctivitis refers to a symptom duration of 3 to 4 weeks from presentation, usually only lasting 1 to 2 weeks, whereas chronic is defined as lasting more than 4 weeks.

Apart from being caused by various infective agents, conjunctivitis may also be associated with some systemic illnesses, including Stevens-Johnson syndrome, keratoconjunctivitis sicca, nutritional deprivation (especially vitamin A deficiency), congenital metabolic syndromes, such as porphyria and Richner-Hanhart syndrome and immune-related disorders, such as Reiter syndrome.