Adult Infectious Conjunctivitis PDF

GP Eyes - Dr Malcolm McKellar | Adult Infectious Conjunctivitis http://www.gpeyes.co.nz/index.php?id=94 Infectious conjunctivitis is one of the commonest causes of a red eye. The symptoms and signs are usually quite specifi...

GP Eyes - Dr Malcolm McKellar | Adult Infectious Conjunctivitis http://www.gpeyes.co.nz/index.php?id=94 Infectious conjunctivitis is one of the commonest causes of a red eye. The symptoms and signs are usually quite specific and with a careful history and examination one can usually be sure of the diagnosis and institute a management plan. Included in this document History Examination Distinguishing conjunctivitis from other red eyes Distinguishing bacterial from viral infection Distinguishing conjunctivitis from preseptal cellulitis Management What to tell the patient Non-resolution Managing patients who don't improve When to refer Key points History Most conjunctivitis comes on over a day or two. Patients usually complain of a foreign body sensation or grittiness. The symptoms are normally worse in the morning and the eyelids are often stuck together on awakening. Mild photophobia is common. There is often a history of recent or current URTI. Very occasionally there is a history of chlamydial infection. Examination Vision The vision is usually normal or mildly reduced. If the patient is photophobic or the eye is very watery, try testing with the room darkened or after instilling a local anaesthetic. Preauricular lymph nodes Tenderness and swelling of the pre-auricular nodes is almost pathognomonic of adenoviral conjunctivitis. The eyelids The eyelids are often puffy although the lids are not inflamed in the classical sense; i.e. there is no cellulitis. Most patients have some crusting. The conjunctiva The conjunctiva is inflamed by definition. The conjunctival vessels are engorged and look like tiny springs (Fig. 1). To confirm that it is the conjunctival vessels that are inflamed rather than the underlying scleral vessels, move the conjunctiva over the sclera. This can usually be achieved by rubbing the edge of the eyelid over the conjunctiva. The regional distribution of the redness is important. In conjunctivitis, as opposed to, for example iritis, the inflammation is usually more evident in the fornix than at the limbus, so it is important to pull the lower lid down and check which part of the eye seems most inflamed. In bacterial infection the conjunctiva has a darker, ‘brick-red’ appearance whereas in viral infection the colour is more ‘pink-red’. In viral conjunctivitis, small, often pin-point, conjunctival haemorrhages are common (Fig. 2). Bacterial infection is characterised by purulent discharge (Fig. 3). Fig. 1. Conjunctivitis. The blood Fig. 2. Conjunctival haemorrhages Fig. 3. The thick mucopurulent vessels of the conjunctiva are that are almost pathognomonic of viral discharge of bacterial conjunctivitis. engorged and look like tiny coiled conjunctivitis. springs. These blood vessels appear superficial and can be easily moved over the underlying scleral vessels, 1 of 3 2/28/2011 5:33 PM GP Eyes - Dr Malcolm McKellar | Adult Infectious Conjunctivitis http://www.gpeyes.co.nz/index.php?id=94 which are normal. There is a conjunctival haemorrhage present. Cornea In almost all cases of conjunctivitis the cornea is uninvolved and crystal clear. Even if the cornea is involved it is usually clear to the naked eye. Iris and pupil The iris details are always clear and the pupil reacts normally because there is no intraocular inflammation. Distinguishing conjunctivitis from other red eyes Conjunctivitis is not really painful and the symptoms are usually worse in the morning. Patients feel as if they have a small foreign body in the eye. In most patients the disease is bilateral and symmetrical, but one eye can be affected more than the other, and infection often begins in one eye and spreads a few days later to the opposite side. The vision remains essentially normal, the pupil responses are normal and there is always some mucoid or purulent discharge. Many patients have an associated upper respiratory tract infection and many will know of others who are currently suffering from the same condition. Preauricular lymphadenopathy and pinpoint conjunctival haemorrhages are almost pathognomonic of viral conjunctivitis. Distinguishing bacterial from viral infection The discharge in viral infection is more watery than the typically mucopurulent discharge of bacterial conjunctivitis. Viral infection of the conjunctiva usually results in a pinkish tinge of the conjunctiva whereas bacterial infection causes a more ‘brick-red’ colouring. Distinguishing conjunctivitis from preseptal cellulitis Most conjunctivitis causes a degree of eyelid swelling due to both the infection itself and eyelid rubbing. However the lid swelling is an oedematous process and can usually be distinguished from infectious cellulitis which is more deeply red, firm, hot and tender. Management Supportive measures Instruct the patient to clean the eyelids each morning with cooled boiled water and apply cool compresses throughout the day. Warm compresses can be used to treat tender lymph nodes. A broad brimmed hat and sunglasses are very helpful if there is significant photophobia, some patients will need a pair of ‘clip-ons’ over the top of regular sunglasses. Artificial tears help to soothe the eye and vasoconstrictors can be used sparingly to whiten the eye. Keeping these drops in the refrigerator makes them more refreshing. Don’t forget simple analgesia. Paracetamol helps people with conjunctivitis. Antibiotics Most conjunctivitis will resolve without treatment whether or not it is bacterial or viral in origin. There is a very good argument not to treat ANY conjunctivitis whether viral or bacterial. The best antibiotic to use is chloramphenicol. Swabs You do not need to take a swab before starting treatment. Eye swabs can be difficult to interpret, as it is very easy to contaminate a conjunctival swab with eyelid/eyelash flora. Many patients have organisms such as S. epidermidis living as commensals in the conjunctival sac. Reserve culturing for atypical and resistant cases. What to tell the patient Advise patients that conjunctivitis is a highly contagious disease that normally resolves without treatment. The symptoms are usually marked for one week then settle over two to three weeks. Tell patients to pay meticulous attention to hygiene, washing their hands after touching their eyes and using a separate towel and face cloth. People with conjunctivitis should avoid contact with elderly, young and infirm patients. Non resolution Distinguish between slow resolution and non resolution. Conjunctivitis takes several weeks to settle although there should be some improvement over that time. If there is clearly no resolution consider the following. 2 of 3 2/28/2011 5:33 PM GP Eyes - Dr Malcolm McKellar | Adult Infectious Conjunctivitis http://www.gpeyes.co.nz/index.php?id=94 Fig. 4. Allergy to eye drops. Courtesy Dr M.J. Elder) Allergy to treatment Allergy to topical medications is the commonest cause of ‘non resolution’. The key features are itch and eyelid oedema. Usually there is a history of some improvement followed by deterioration. Often the eyelids and cheeks are red and swollen due to skin allergy caused by eye drops spilling from the conjunctival sac (Fig. 4). Chlamydia Enquire discretely about the possibility of chlamydial disease. The conjunctivitis usually begins about two weeks after sexual contact. Chloramphenicol is ‘bacteriostatic’ against chlamydia. Trachoma Consider trachoma in Polynesian, Middle Eastern or African patients. Managing patients who don’t improve Go back over the history and examination to be sure that you have the correct diagnosis. Stop antibiotic treatment for 24 hours. Medication allergy usually settles within 24 hours and stopping antibiotic treatment makes it much more likely that you will get a positive culture if you swab the eye. Swab the conjunctival sac and eyelid margin separately, avoiding any contact with the skin. If you think that chlamydial infection is a possibility, ‘scrub’ the conjunctiva with a chlamydial swab; you are trying to get some epithelial cells on the swab. Ask for both Gram and Giemsa stains. When to refer Refer all patients with vision less that 6/12, and non resolving or chlamydial infection. All patients with cellulitis (but not oedema) of the eyelids should be reviewed by an ophthalmologist Key points Conjunctivitis is characterised by a specific syndrome of symptoms and signs. It usually comes on over several days, is associated with URTI and does not affect the vision. The disease is usually bilateral, but one eye may be affected more than the other. Treatment is essentially supportive and there are few indications for antibiotic treatment. © GP Eyes - Dr Malcolm McKellar 2011 3 of 3 2/28/2011 5:33 PM