konjungtivitis

Conjunctivitis

Creted by: dj_ry_cel@yahoo.co.id / wowo-mm.blogspot.com

Symptoms

Eyes with conjunctivitis

Redness (hyperaemia), irritation (chemosis) and watering (epiphora) of the eyes are symptoms common to all forms of conjunctivitis.

Acute allergic conjunctivitis is typically itchy, sometimes distressingly so, and often involves some lid swelling. Chronic allergy often causes just itch or irritation.

Viral conjunctivitis is often associated with an infection of the upper respiratory tract, a common cold, and/or a sore throat. Its symptoms include watery discharge and variable itch. The infection usually begins with one eye, but may spread easily to the other.

Bacterial conjunctivitis due to the common pyogenic (pus-producing) bacteria causes marked grittiness/irritation and a stringy, opaque, grey or yellowish mucopurulent discharge (gowl, goop, "gunk", "eye crust", or other regional names, officially known as 'gound') that may cause the lids to stick together (matting), especially after sleeping. Another symptom that could be caused by bacterial conjunctivitis is severe crusting of the infected eye and the surrounding skin. However discharge is not essential to the diagnosis, contrary to popular belief. Bacteria such as Chlamydia trachomatis or Moraxella can cause a non-exudative but persistent conjunctivitis without much redness. The gritty and/or scratchy feeling is sometimes localized enough for patients to insist they must have a foreign body in the eye. The more acute pyogenic infections can be painful. Like viral conjunctivitis, it usually affects only one eye but may spread easily to the other eye. However, it is dormant in the eye for three days before the patient shows signs of symptoms.

Irritant or toxic conjunctivitis is irritable or painful when the infected eye is pointed far down or far up. Discharge and itch are usually absent. This is the only group in which severe pain may occur.

Inclusion conjunctivitis of the newborn (ICN) is a conjunctivitis that may be caused by the bacteria Chlamydia trachomatis, and may lead to acute, purulent conjunctivitis.^[3] However, it is usually self-healing.^[3]

Signs

Infection (redness) of the conjunctiva, one of them is by looking at a host pink eye person to person, but may be quite mild. Except in obvious pyogenic or toxic/chemical conjunctivitis, a slit lamp (biomicroscope) is needed to have any confidence in the diagnosis. Examination of the tarsal conjunctiva is usually more diagnostic than the bulbar conjunctiva.

Allergic conjunctivitis shows pale watery swelling or edema of the conjunctiva and sometimes the whole eyelid, often with a ropy, non-purulent mucoid discharge. There is variable redness.

Viral conjunctivitis, commonly known as "pink eye", shows a fine diffuse pinkness of the conjunctiva which is easily mistaken for the 'ciliary injection' of iritis, but there are usually corroborative signs on bio microscopy, particularly numerous lymphoid follicles on the tarsal conjunctiva, and sometimes a punctate keratitis.

Pyogenic bacterial conjunctivitis shows an opaque purulent discharge, a very red eye, and on bio microscopy there are numerous white cells and desquamated epithelial cells seen in the tear duct along the lid margin. The tarsal conjunctiva is a velvety red and not particularly follicular. Non-pyogenic infections can show just mild infection and be difficult to diagnose. Scarring of the tarsal conjunctiva is occasionally seen in chronic infections, especially in trachoma.

Irritant or toxic conjunctivitis show primarily marked redness. If due to splash injury, it is often present only in the lower conjunctival sac. With some chemicals—above all with caustic alkalis such as sodium hydroxide—there may be necrosis of the conjunctiva with a deceptively white eye due to vascular closure, followed by sloughing of the dead epithelium. This is likely to be associated with slit-lamp evidence of anterior uveitis.

Treatment and management

Conjunctivitis sometimes requires medical attention. The appropriate treatment depends on the cause of the problem. For the allergic type, cool water poured over the face with the head inclined downward constricts capillaries, and artificial tears sometimes relieve discomfort in mild cases. In more severe cases, non-steroidal anti-inflammatory medications and antihistamines may be prescribed. Some patients with persistent allergic conjunctivitis may also require topical steroid drops.

Bacterial

Bacterial conjunctivitis usually resolves with no treatment. Treatment with antibiotic eye drops or ointments ( such as chloramphenicol or fusidic acid ) does however speed recovery. Gentamicin and Vigamox, (moxifloxacin) are commonly used in the U.S.^[4] Evidence suggests there is a modest reduction in duration from an average of 4.625 days (untreated controls) to 3.3 days for those given immediate antibiotics. Deferring antibiotics yields almost the same duration as those immediately starting treatment with 3.9 days duration, but with half the two-week clinic reattendance rate.^[5]

Viral

Although there is no specific treatment for viral conjunctivitis, symptomatic relief may be achieved with warm compresses^[6] and artificial tears. For the worst cases, topical corticosteroid drops may be prescribed to reduce the discomfort from inflammation. However prolonged usage of corticosteroid drops increases the risk of side effects. Antibiotic drops may also be used for treatment of complementary infections. Patients are often advised to avoid touching their eyes or sharing towels and washcloths. Viral conjunctivitis usually resolves within 3 weeks. However, in worse cases it may take over a month. In past times breast milk was often used to relieve the symptoms of conjunctivitis.

Chemical

Conjunctivitis due to burns, toxic and chemical require careful wash-out with saline, especially beneath the lids, and may require topical steroids. The more acute chemical injuries are medical emergencies, particularly alkali burns, which can lead to severe scarring, and intraocular damage. Fortunately, such injuries are uncommon.

If you think you might have conjunctivitis, you should

• Keep your hands away from your eyes;
• Thoroughly wash hands before and after applying eye medications;
• Do not share towels, washcloths, cosmetics or eyedrops with others;
• Seek treatment promptly.
• Small children, who may forget these precautions, should be kept away from school, camp and the swimming pool until the condition is cured.

Infectious conjunctivitis, caused by bacteria, is usually treated with antibiotic eye drops and/or ointment. Other infectious forms, caused by viruses, can't be treated with antibiotics. They must be fought off by your body's immune system. But some antibiotics may be prescribed to prevent secondary bacterial infections from developing.

When treating allergic and chemical forms of conjunctivitis, the cause of the allergy or irritation must first be removed. For instance, avoid contact with any animal if it causes an allergic reaction. Wear swimming goggles if chlorinated water irritates your eyes. In cases where these measures won't work, prescription and over-the-counter eye drops are available to help relieve the discomfort.

Pathophysiology

Adenoviral conjunctivitis is the most common cause of viral conjunctivitis. Particular subtypes of adenoviral conjunctivitis include epidemic keratoconjunctivitis (pink eye) and pharyngoconjunctival fever. Transmission occurs through contact with infected upper respiratory droplets, fomites, and contaminated swimming pools.

Primary ocular herpes simplex infection is common in children and usually is associated with a follicular conjunctivitis. Infection usually is caused by HSV type I, although HSV type II may be a cause, especially in neonates. Recurrent infection, typically seen in adults, usually is associated with corneal involvement.

VZV can affect the conjunctiva during primary infection (chickenpox) or secondary infection (zoster). Infection can be caused by direct contact with VZV or zoster skin lesions or by inhalation of infectious respiratory secretions.

Picornaviruses cause an acute hemorrhagic conjunctivitis that is clinically similar to adenoviral conjunctivitis but is more severe and hemorrhagic. Infection is highly contagious and occurs in epidemics.

Molluscum contagiosum may produce a chronic follicular conjunctivitis that occurs secondary to shedding of viral particles into the conjunctival sac from an irritative eyelid lesion.

Vaccinia virus has become a rare cause of conjunctivitis because with the elimination of smallpox, the vaccination rarely is administered. Infection occurs through accidental inoculation of viral particles from the patient's hands.

HIV is the etiologic agent of acquired immunodeficiency syndrome (AIDS). Ocular abnormalities in patients with AIDS primarily affect the posterior segment, but anterior segment findings have been reported. When conjunctivitis occurs in a patient with AIDS, it tends to follow a more severe and prolonged course than in patients without AIDS. In general, patients with AIDS may develop a transient nonspecific conjunctivitis, characterized by irritation, hyperemia, and tearing, that requires no specific treatment. Microsporidia has been isolated from the cornea and conjunctiva of several patients with AIDS and keratoconjunctivitis. In these patients, symptoms included foreign body sensation, blurred vision, and photophobia; most cases resolved without antimicrobial therapy.

Physical Sign/Symptom

• Typical signs of adenoviral conjunctivitis include preauricular adenopathy, epiphora, hyperemia, chemosis, subconjunctival hemorrhage, follicular conjunctival reaction, and occasionally a pseudomembranous or cicatricial conjunctival reaction. The cornea often demonstrates a punctate epitheliopathy. The eyelids often are edematous and ecchymotic. In severe cases, there can be a corneal epithelial defect. It typically begins in one eye and progresses to the fellow eye over a few days. The second eye is usually less significantly involved.
• With HSV infection, vesicles may be present on the eyelid or face, the eyelids may be swollen, and an ulcerative blepharitis may be present.
• Corneal involvement in HSV manifests as a dendritic keratitis with typical features of linear branching and dendritic figures.
• Small papular lesions that erupt along the lid margin or at the limbus are present with varicella conjunctivitis. These lesions may resolve without sequelae, or they may become pustular and form painful reactive conjunctival ulcers.
• In herpes zoster ophthalmicus, look for skin involvement with the appearance of a dermatomal pattern of vesicles. These vesicles may become necrotic, resulting in pitted scarring of the skin. Conjunctival involvement includes hyperemia, follicular or papillary conjunctivitis, and a serous or mucopurulent discharge. Preauricular adenopathy is common. Very early in the process, there may be multiple fine dendritic corneal lesions, which disappear over a few days without treatment.
• Acute hemorrhagic conjunctivitis starts unilaterally but rapidly involves the fellow eye within 1 or 2 days. Signs on examination include a swollen, edematous eyelid, and pronounced hemorrhage beneath the bulbar conjunctiva.

Causes

A variety of viruses can be responsible for conjunctival infection. Adenovirus is the most common cause, and HSV is the most problematic. Less common causes include VZV, picornavirus (enterovirus 70, Coxsackie A24), poxvirus (molluscum contagiosum, vaccinia), and HIV.

Treatment

Medical Care

Treatment of adenoviral conjunctivitis is supportive. No evidence exists that demonstrates efficacy of antiviral agents.

• Patients should be instructed to use cold compresses and lubricants, such as artificial tears, for comfort.
• Topical vasoconstrictors and antihistamines may be used for severe itching but generally are not indicated because they are minimally helpful and may cause rebounding of symptoms, as well as local toxicity and hypersensitivity.
• For patients who may be susceptible, a topical astringent or antibiotic may be used to prevent bacterial superinfection.
• Topical steroids may be used for pseudomembranes or when subepithelial infiltrates impair vision, although subepithelial infiltrates may recur after discontinuing the steroids. Extreme caution should be taken when using corticosteroids, as they may worsen an underlying HSV infection.
• An in vitro study using adenovirus 8 and A549 human epithelial cell cultures demonstrated that povidone-iodine at a concentration of 1:10 (0.8%) is highly effective against free adenovirus, less effective against intracellular adenoviral particles in already infected cells, and not significantly cytotoxic for healthy cells. Thus, povidone-iodine 0.8% may represent a potential option to reduce contagiousness in cases of adenoviral infections.
• Patients with conjunctivitis caused by HSV usually are treated with topical antiviral agents, including idoxuridine solution and ointment, vidarabine ointment, and trifluridine solution. An ophthalmologist should see any patient with ocular HSV infection. Treatment of HSV keratitis is discussed in Keratitis, Herpes Simplex.
• Treatment of VZV eye disease includes oral acyclovir, 600-800 mg, 5 times daily for 7-10 days, to terminate viral replication. Topical corticosteroids usually are not indicated for conjunctivitis or keratitis.
• Treatment of acute hemorrhagic conjunctivitis is supportive as in adenoviral infection and includes bed rest, cold compresses, and analgesics. Antibiotics have no useful role unless bacterial superinfection is present.
• For conjunctivitis associated with molluscum contagiosum, disease will persist until the skin lesion is treated. Removal of the central core of the lesion or inducement of bleeding within the lesion usually is enough to cure the infection. Occasionally, surgical excision is required.
• Other viral causes of conjunctivitis generally are self-limited and treated supportively with compresses for comfort and topical antibiotics as necessary to prevent bacterial superinfection.

Medication

Medications used in the treatment of viral conjunctivitis include the following: topical artificial tears, 4-8 times per day, for 1-3 weeks; topical vasoconstrictor/antihistamine, 4 times per day, for severe itching; topical steroids for pseudomembranes and subepithelial infiltrates; topical antibiotic to prevent bacterial superinfection; topical antiviral agents for HSV infection; and oral acyclovir for VZV infection.

Deterrence/Prevention

• Prevention of transmission, especially in health care facilities, is extremely important.
• Careful hand washing before seeing every patient, proper cleansing of instruments, and frequent changing of multiuse ophthalmic drops are vital.
• Using a single infective examination room, as well as educating the staff and the patient, is important.
• Patients should be instructed to take contagion and isolation precautions for at least 2 weeks or as long as the eyes are red and weeping.

Complications

• Complications include the following: punctate keratitis with subepithelial infiltrates, bacterial superinfection, corneal ulceration with keratoconjunctivitis, and chronic infection.
• Epithelial keratitis may accompany viral conjunctivitis. Punctate epithelial erosions that stain with fluorescein characterize viral keratitis. Rarely, these changes are sufficiently distinctive morphologically to allow identification of a specific type of virus as the etiologic agent. If the conjunctivitis persists or is severe, disturbances in the anterior stroma beneath the epithelial abnormalities may occur. In general, the stromal or subepithelial abnormalities are transient and resolve despite persistence of epithelial keratitis. However, in cases of adenoviral infection, the stromal abnormalities may persist for months to years, long after the epithelial changes have resolved. In such cases, these subepithelial infiltrates are considered to be immunologic in origin, the result of antigen-antibody reaction. If they are in the pupillary axis, they may cause decreased vision and/or glare.

Prognosis

• Most cases of viral conjunctivitis are acute, benign, and self-limited. The infection usually resolves spontaneously within 2-4 weeks. Subepithelial infiltrates may last for several months, and, if in the visual axis, they may cause decreased vision or glare.

References

http://www.wikipedia.com

http://emedicine.medscape.com