General Medical Information

Conjunctivitis, Episcleritis, and Scleritis

Jean Edwards Holt

Conjunctivitis is inflammation of the mucous membrane covering the globe and lining the inner part of the eyelids. Conjunctivitis usually is infectious or allergic. Viral conjunctivitis caused by the adenovirus group is the common pink eye for which children are sent home from school. Symptoms are mild, with only diffuse redness of the conjunctiva, minimal clear discharge, and perhaps a tender preauricular node or associated pharyngitis. The condition is generally self-limited, but it is highly contagious in its early stages. Bacterial conjunctivitis is commonly caused by strains of Staphylococcus, Diplococcus, or Haemophilus. The patient has mild symptoms of grittiness and photophobia. The most characteristic finding is that the lids stick together overnight because of a mucopurulent discharge. If acute, copious purulence is present, the offending agent may be Neisseria gonorrhoeae, and further systemic investigation should be performed. Routine culturing is not necessary because there usually is a prompt response to broad-spectrum topical antibiotics. If symptoms persist for more than 2 weeks, an alternative diagnosis should be entertained.

Allergic conjunctivitis can occur in response to topical medications, cosmetics, aerosols, or as part of the hay fever complex. The first exposure can be dramatic with severe itching and profuse watering associated with marked edema of the conjunctiva (chemosis), and the eyelids may be swollen shut, similar to the reaction of an insect sting. This condition can be unilateral or bilateral. It usually is managed with cold compresses and perhaps topical or systemic antihistamines after elimination of the offending agent, if possible.

Deep to the conjunctiva are the episcleral tissues and sclera. If the inflammation is not superficial, the patient reports deep pain, and the erythema appears dark red or purplish, episcleritis or scleritis should be considered. Episcleritis usually is an isolated patch of inflammation without sequelae. In contrast, more than 50% of cases of scleritis are associated with systemic disease, usually of a rheumatic nature. Recurrent inflammation of a pterygium can produce a discrete area of conjunctivitis.