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Conjunctivitis (ie, inflammation of the conjunctiva) is the most common ocular disease worldwide. It is characterized by a pink appearance (hence the common term pink eye) because of sub-conjunctival blood vessel hemorrhages.
General symptoms include foreign body sensation, scratching or burning sensation, itching, and photophobia. Conjunctivitis may be unilateral or bilateral, but the infection usually starts in one eye and then spreads to the other eye by hand contact.
The four main clinical features important to evaluate are the type of discharge (ie, watery, mucoid, purulent, or mucopurulent), type of conjunctival reaction (ie, follicular or papillary), presence of pseudomembranes or true membranes, and presence or absence of lymphadenopathy (ie, enlargement of the preauricular and submandibular lymph nodes where the eyelids drain). Pseudomembranes consist of coagulated exudate that adheres to the surface of the inflamed conjunctiva. True membranes form when the exudate adheres to the superficial layer of the con-junctiva, and removal results in bleeding. Follicles are multiple, slightly elevated lesions encircled by tiny blood vessels; they look like grains of rice. Papillae are hyperplastic conjunctival epithe-lium in numerous projections that are usually seen as a fine mo-saic pattern under slit-lamp examination. Diagnosis is based on the distinctive characteristics of ocular signs, acute or chronic pre-sentation, and identification of any precipitating events. Positive results of swab smear preparations and cultures confirm the diagnosis.
Conjunctivitis is classified according to its cause. The major causes are microbial infection, allergy, and irritating toxic stimuli. A wide spectrum of exogenous microbes can cause conjunctivitis, includ-ing bacteria (eg, Chlamydia), viruses, fungus, and parasites. Con-junctivitis can also result from infection of an existing ocular infection or can be a manifestation of a systemic disease.
Bacterial conjunctivitis can be acute or chronic. The acute type can develop into a chronic condition. Signs and symptoms can vary from mild to severe. Chronic bacterial conjunctivitis is usually seen in patients with lacrimal duct obstruction, chronic dacryocystitis, and chronic blepharitis. The most common caus-ative microorganisms are Streptococcus pneumoniae, Haemophilusinfluenzae, and Staphylococcus aureus.
Bacterial conjunctivitis manifests with an acute onset of red-ness, burning, and discharge. There is papillary formation, con-junctival irritation, and injection in the fornices. The exudates are variable but are usually present on waking in the morning. The eyes may be difficult to open because of adhesions caused by the exudate. Purulent discharge occurs in severe acute bacterial in-fections, whereas mucopurulent discharge appears in mild cases. In gonococcal conjunctivitis, the symptoms are more acute. The exudate is profuse and purulent, and there is lymphadenopathy. Pseudomembranes may be present.
Viral conjunctivitis (Fig. 58-18) can also be acute and chronic. The discharge is watery, and follicles are prominent. Severe cases include pseudomembranes. The common causative organisms are adenovirus and herpes simplex virus. Conjunctivitis caused by adenovirus is highly contagious. The symptoms include extreme tearing, redness, and foreign body sensation that can involve one or both eyes. The condition is usually preceded by symptoms of upper respiratory infection. Corneal involvement causes extreme photophobia. There is lid edema, ptosis, conjunctival hyperemia (ie, dilation of the conjunctival blood vessels), watery discharge, follicles, and papillae. These signs and symptoms vary from mild to severe and may last for 2 weeks. Viral conjunctivitis, although self-limited, tends to last longer than bacterial conjunctivitis.
Epidemic keratoconjunctivitis (EKC) is most often accompa-nied by preauricular lymphadenopathy and occasionally perior-bital pain. There are marked follicular and papillary formations. EKC can lead to keratopathy. EKC is a highly contagious viral conjunctivitis that is easily transmitted from one person to an-other among household members, school children, and health care workers. The outbreak of epidemics is seasonal, especially during the summer when people frequent swimming pools.
Chlamydial conjunctivitis includes trachoma and inclusion conjunctivitis. Trachoma is an ancient disease and is the leading cause of preventable blindness in the world. It is prevalent in areas with hot, dry, and dusty climates and in areas with poor living conditions. It is spread by direct contact or fomites, and the vec-tors can be insects such as flies and gnats.
Trachoma is a bilateral chronic follicular conjunctivitis ofchildhood that leads to blindness during adulthood, if left un-treated. The onset in children is usually insidious, but it can be acute or subacute in adults. The initial symptoms include red inflamed eyes, tearing, photophobia, ocular pain, purulent exu-dates, preauricular lymphadenopathy, and lid edema. Initial oc-ular signs include follicular and papillary formations. At the middle stage of the disease, there is an acute inflammation with papillary hypertrophy and follicular necrosis, after which trichiasis (turning inward of hair follicles) and entropion begin to develop. The lashes that are turned in rub against the cornea and, after prolonged irritation, cause corneal erosion and ulceration. The late stage of the disease is characterized by scarred conjunctiva, subepithelial keratitis, abnormal vascularization of the cornea (pannus), and residual scars from the follicles that look like de-pressions in the conjunctiva (ie, Herbert’s pits). Severe corneal ulceration can lead to perforation and blindness.
Inclusion conjunctivitis affects sexually active young people who have genital chlamydial infection. Transmission is by oral-genital sex or hand-to-eye transmission. It has been reported that indirect transmission has been acquired from inadequately chlo-rinated swimming pools. The eye lesions usually appear a week after exposure and may be associated with a nonspecific urethritis or cervicitis. The discharge is mucopurulent, follicles are present, and there is lymphadenopathy.
Immunologic or allergic conjunctivitis is a hypersensitivity reac-tion as a part of allergic rhinitis (hay fever), or it can be an inde-pendent allergic reaction. The patient usually has a history of an allergy to pollens and other environmental allergens. There is ex-treme itching, epiphora (ie, excessive secretion of tears), injection, and usually severe photophobia. The stringlike mucoid discharge is usually associated with rubbing the eyes because of severe itch-ing. Vernal conjunctivitis is also known as seasonal conjunctivi-tis because it appears mostly during warm weather. There may be large formations of papillae that have a cobblestone appearance. It is more common in children and young adults. Most affected individuals have a history of asthma or eczema.
Chemical conjunctivitis can be the result of medications, chlo-rine from swimming pools (more common during the summer), exposure to toxic fumes among industrial workers, or exposure to other irritants such as smoke, hair sprays, acids, and alkalis.
The management of conjunctivitis depends on the type. Most types of mild and viral conjunctivitis are self-limiting, benign conditions that may not require treatment and laboratory procedures. For more severe cases, topical antibiotics, eye drops, or ointment are prescribed.
Patients with gonococcal conjunctivitis require urgent antibiotic therapy. If left untreated, this ocular disease can lead to corneal perforation and blindness. The systemic complications can include meningitis and generalized septicemia.
Acute bacterial conjunctivitis is almost always self-limiting. If left untreated, the disease follows a 2-week course with resolution of symptoms. If treated with appropriate antibiotics, it may last for a few days, with the exception of gonococcal and staphylococcal conjunctivitis. Viral conjunctivitis is not responsive to any treatment. Cold compresses may alleviate some symptoms. It is extremely important to remember that viral conjunctivitis, especially EKC, is highly transmissible. Patients must be made aware of the contagious nature of the disease, and adequate in-structions must be given. These instructions should include an emphasis on handwashing and avoiding sharing hand towels, face cloths, and eye drops. Tissues should be directly discarded into a trashcan.
Proper steps must be taken to avoid nosocomial infections. Frequent hand hygiene, procedures for environmental cleaning, and disinfection of equipment used for eye examination must be strictly followed at all times (Chart 58-9). During outbreaks of conjunctivitis caused by adenovirus, it is necessary that health care facilities assign specified areas for treating patients with or suspected of having conjunctivitis caused by adenovirus to pre-vent spread. All forms of tonometry must be avoided unless med-ically indicated. All multidose medications must be discarded at the end of each day or when contaminated. Infected employees and others must not be allowed to work or attend school until symptoms have resolved, which can take 3 to 7 days.
Patients with allergic conjunctivitis, especially recurrent ver-nal or seasonal conjunctivitis, are usually given corticosteroids in ophthalmic preparations. Depending on the severity of the dis-ease, they may be given oral preparations. Use of vasoconstrictors, such as topical epinephrine solution, cold compresses, ice packs, and cool ventilation usually provide comfort by decreasing swelling.
For trachoma, treatment is usually broad-spectrum antibiotics administered topically and systemically. Surgical management in-cludes the correction of trichiasis to prevent conjunctival scarring. Adult inclusion conjunctivitis requires a 1-week course of anti-biotics. Prevention of reinfection is important, and affected individuals and their sexual partners must be advised to seek as-sessment and treatment for sexually transmitted disease, if indicated.
For conjunctivitis caused by chemical irritants, the eye must be irrigated immediately and profusely with saline or sterile water.
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