We’ve probably all either had or know someone who’s had conjunctivitis at some point. Essentially it is inflammation of the thin lining of the eyes, called the conjunctivae. People often have red, painful eyes (one or both) which can be itchy, runny and produce a sticky discharge. However, conjunctivitis should not cause much of a change to the sharpness of your vision - if this is happening, then see you doctor for a consultation.
Broadly speaking there are two forms of conjunctivitis:
Infective conjunctivitis itself has two main causes - viral and bacterial. It can affect one eye at first, but often spreads to affect the other eye, due in part to how close they are, and also in part to the fact it is almost impossible not to touch your own face, which causes spread.
There are a few key signs that can tell the two apart, although it can sometimes be tricky. Generally, viral conjunctivitis gives you a sticky but fairly translucent discharge from the affected eye. There can often be an associated viral upper respiratory tract infection - so if you’ve had a recent cough or cold, or one at around the same time and develop itchy red discharging eyes, the likelihood is that it is viral in nature.
Where bacterial conjunctivitis differs mainly is the consistency of the discharge. It is often thicker, and much like pus. This often causes eyelids themselves to be stuck together, more often in the mornings, and a yellow crust to form around the margins of the eyelids.
Allergic conjunctivitis :
Whereas infective causes can affect one eye at first, allergic conjunctivitis almost exclusively affects both from the outset. It can give a similar redness to the eyes, but the itching can be more intense, and the eyes normally water profusely without any sticky discharge. If you suffer from this, you may have a history of certain allergies and you may notice a certain trigger or seasonal cause - for example, dust, cat hair or pollen in hay-fever. You can read more about this, and how to tackle it, in my earlier blog: Itchy, Sneezy Wheezy.
For both bacterial and viral forms, good hand hygiene and avoiding towel-sharing is essential to try and minimise spread to others. If you wear contact lenses normally, it really goes without saying that wearing them if you have conjunctivitis is a pretty bad idea - so avoid those too until you’re completely better. Cold flannels wiped over the eyes can also be quite soothing. And for children, there is no recommended school exclusion - so unlucky for the kids - it’s back to school for them.
Bacterial conjunctivitis can easily be treated with antibiotic creams or drops, and usually resolves within a week or so. The medication needs to be applied about 4 times per day for the course of treatment, sometimes more frequently. Viral conjunctivitis often resolves on its own without treatment over a similar time period.
Allergic conjunctivitis can be treated with antihistamine drops or tablets, or a combination of both. 2% sodium cromoglicate drops (available over the counter as Opticrom) are a good starting point, or any freely available antihistamine like cetirizine or loratidine. Avoiding the trigger in question can be very difficult, but if you can, then it will obviously help.
Remember, if you’ve tried these treatments, and things aren’t getting better then it’s important to see your doctor again. They may need to re-examine you, take a swab from the eyes, or send you on for specialist assessment.
If you do need to see an specialist eye consultant, my colleague Dr Jaheed Khan comes with my highest recommendation. Click here to visit his website.
This blog can also be found on Dr Morton's - The Medical Helpline