In the April issue of Retail Pharmacy magazine, we delved into the topic of allergic conjunctivitis: how this condition can be managed, what it can lead to if left untreated, and the services that pharmacists can offer in this space.
What is allergic conjunctivitis?
Allergic conjunctivitis is a common eye condition typically caused by a reaction to an allergen.
“[It’s] caused by an allergic reaction to substances such as pollen, dust mites, pet dander or mould spores,” said Dr Jacinta Johnson, Senior Lecturer In Pharmacy at the University of South Australia’s School of Pharmacy and Medical Sciences.
Another possible cause includes an allergic reaction to foods or food additives, although she says this is less common.
“Other triggers can include allergic reactions to medicated eye drops or ointments or contact lenses and solutions,” Dr Johnson said.
“People who have a history of other allergies or asthma may be more likely to develop allergic conjunctivitis, and it can be as a symptom of hay fever [allergic rhinitis]. Exposure to irritants like cigarette smoke, perfume and other chemicals can also trigger symptoms.
“When these allergens come into contact with the eyes, the body releases histamine, which causes inflammation and itching of conjunctiva – the thin, transparent membrane that covers the whites of the eyes and inside the eyelids.”
Symptoms of allergic conjunctivitis typically include “redness, itching, tearing, swollen eyelids and a burning or gritty sensation in the eyes”, according to Dr Johnson.
“Some people also experience blurred vision and sensitivity to light,” she said. “This is known as photophobia.”
Allergic conjunctivitis can result in quite debilitating symptoms that may be mistaken for other eye conditions, such as ‘pink eye’. But Dr Johnson says the difference is that allergic conjunctivitis is caused by “an allergic reaction, and isn’t contagious, whereas pink eye is caused by a viral or bacterial infection and is highly contagious”.
“While both conditions can cause similar symptoms, like redness, itching and tearing, there are some important differences between the two,” she said.
Dr Johnson continued: “With allergic conjunctivitis, both eyes are usually affected simultaneously. Symptoms occur soon after exposure to an allergen. The discharge is clear and watery. On the other hand, pink eye can affect one or both eyes and usually develops a few days after exposure to the causative virus or bacterial. In pink eye, discharge from the eye can be thicker, and yellow or green in colour, and there may be accompanying cold-like symptoms such as a runny nose and sore throat.”
Stephanie Conway-Allen, Associate Professor of Pharmacy Practice at Massachusetts College of Pharmacy and Health Sciences in the US, agrees that generally speaking, conjunctivitis refers to “inflammation of the conjunctiva”.
She adds that while there may be “several causes of conjunctivitis”, allergic conjunctivitis specifically refers to “an allergenic or an allergy mediated conjunctivitis”, although this isn’t “an infection” such as may be found in viral or bacterial conjunctivitis or pink eye.
“So, an allergic conjunctivitis, specifically, is an immune response to allergens,” she said. “This is very different from bacterial or viral conjunctivitis because the response is different, and the treatment is going to also [be different]. [Allergic conjunctivitis] is an immune response typically to allergens, as opposed to what we think of for pink eye, which is a bacterial or viral infectious response.”
Elaborating on the symptoms of allergic conjunctivitis, Associate Professor Conway-Allen distinguishes these from bacterial or viral conjunctivitis in that “there shouldn’t be any sort of mucus or discharge” here. The signs and symptoms, she continues, include “itching, watery eyes, red eyes”.
“Patients will often complain of rhinitis as well,” she said, underscoring that all these symptoms are “a response to an allergen”.
Associate Professor Conway-Allen continued: “Another thing to know is there are actually two different types of the more common allergic conjunctivitis, and this is seasonal versus perennial. The seasonal allergies are, as you can imagine, a response to changes in the environment, usually outdoors – this is grass or pollen. So, that can cause seasonal allergies or seasonal allergic conjunctivitis. Perennial conjunctivitis is considered to be more of a chronic condition and is often persistent. It’s associated with indoor allergens, and that includes dust, pet dander, cockroaches.”
In terms of how long allergic conjunctivitis typically lasts, Dr Johnson says symptoms will usually persist “as long as exposure to the allergen continues”.
“This means it can be acute, lasting for a short period of time, or chronic, persisting for several months or even years,” she said. “The duration of symptoms will depend on an individual’s level of exposure to the triggering allergen, the severity of the allergy, and other factors such as their general health and treatments they may be using.”
While allergic conjunctivitis is a response to an allergen, it’s important to note that it may lead to bacterial infections.
“In general, additional infection or discomfort is absolutely possible with allergic conjunctivitis,” Associate Professor Conway-Allen said. “If a patient has allergic conjunctivitis and they’re not treating it, perhaps, and they’re using dirty hands to touch and rub their eyes, they’re going to be predisposed to additional infection … so absolutely, untreated allergic conjunctivitis may become a concern.”
Dr Johnson adds that, if left untreated, not only can allergic conjunctivitis cause ongoing discomfort, which can impact quality of life, but also “the symptoms can worsen and persist for longer periods of time, causing more severe irritation and inflammation”.
“The itching sensation caused by allergic conjunctivitis can result in excessive rubbing of the eyes, which can lead to further irritation and potential corneal abrasion or injury,” Dr Johnson said. “In some cases, untreated allergic conjunctivitis may result in more serious eye conditions such as corneal ulcers, infections or scarring.
“Chronic or repeated exposure to the allergens that trigger allergic conjunctivitis can lead to chronic inflammation and damage to the conjunctiva and other parts of the eye, which may affect vision over time. Fortunately, serious complications due to allergic conjunctivitis are relatively rare.”
Treatment
While the condition can be “uncomfortable and irritating”, the good news is that allergic conjunctivitis isn’t typically a “serious condition and can be effectively managed”, says Dr Johnson.
“Usually, management involves a combination of strategies to identify and reduce – or ideally, remove – exposure to allergens, as well as treatments to help relieve symptoms,” she said. “Typical treatment options include eye drops containing antihistamines, vasoconstrictors, corticosteroids, or mast-cell stabilising medications and/or oral antihistamines.”
Dr Johnson continued: “In addition to avoiding allergens and using medications, other strategies – such as bathing eyes with cool water or using cool compresses to relieve inflammation, washing hands to avoid spreading allergens to the eyes, and wearing wrap-around sunglasses to protect the eyes from allergens and irritants in the air – may also be helpful.
“If preventative strategies and OTC treatment options aren’t sufficient, prescription treatments and allergen immunotherapy for specific allergens can be used to manage severe cases, under supervision of a GP, optometrist or relevant specialist.”
- OTC options
Providing support, education and advice around treatment options is one of the key roles of pharmacists in the space of allergic conjunctivitis, and several products are available to help treat this condition. Dr Johnson says these include antihistamine eye drops such as “levocabastine, ketotifen, pheniramine or loratadine with or without a vasoconstrictive agent like naphazoline”.
“The Australasian Society of Clinical Immunology and Allergy recommends that antihistamine eye drops are not used for more than six weeks, and vasoconstrictor drops are not used for more than 14 days without medical advice,” she said. “Eye drops containing a mast cell stabiliser, such as sodium cromoglycate, can be used for longer periods, although, as they take three to seven days to produce an effect, they’re best used for prevention of symptoms.
“Oral antihistamines can also be helpful when the allergen cannot be avoided. Lubricant eye drops can be used to help flush allergens from the tear fluid.”
Community pharmacist and master herbalist Gerald Quigley says other options for treating allergic conjunctivitis can include options such as an “old fashioned eye bath”, as well as “sterile saline eyedrops – something that’s … isotonic, so it won’t irritate”.
Mr Quigley also cites the importance of keeping eyes lubricated, because issues may arise when eyes dry out – with dry eyes a possible contributing factor to conjunctivitis. My Quigley underscores the benefit of sterile eyedrops in this instance – and not, necessarily, antihistamine eyedrops.
“You need something that’s fairly diluted, and that’s why the sterile water … that’s isotonic, used frequently is a good way [to prevent issues],” he said. “So, if you’ve been working in dust, mowing the lawn, and coping with all these things – as well as wearing your protective goggles …. and also, just irrigating the nose because that’ll be full of [pollen and dust] … again, that’s just all common sense.”
Additionally, Mr Quigley points to the importance of ensuring the immune system is operating optimally, and that while bodies have “an innate ability to cope with particular infections”, supporting the immune system through OTC vitamins, minerals and supplements, such as “immune-boosting vitamin D and C, and zinc”, will help.
Pharmacy’s role
“Community pharmacists play an important role in supporting patients to manage allergic conjunctivitis,” Dr Johnson said. “We can assist by providing non-pharmacological advice, recommendations for OTC treatments to trial, and can recognise when referral to another healthcare professional is necessary.
“Pharmacists can provide services to people with allergic conjunctivitis, such as provision of over-the-counter medicines along with advice for their safe and effective use, patient education to help identify triggers and manage the condition without or in addition to medications, referral to other health professionals where necessary, and monitoring of treatment efficacy and potential adverse effects.”
Another area in which pharmacists can play an important role is in educating patients on the correct use of eye drops, says Dr Johnson.
“The pharmacist has a role in making sure the patients know how to use eyedrops or eye products … making sure that they’re comfortable with administering eye drops [and] making sure that they follow the proper process … that they have the dexterity to remove the top, and to follow the instructions, and to tilt their head back, etc,” she said.
Mr Quigley adds that simple tips pharmacists provide can often make a difference between eyedrops working or going “straight behind down behind their nose”, which is when patients will typically say that “eyedrops taste dreadful” – because they’re not using them as they should be”.
“Simple little hints like that [the correct use of eyedrops] can often mean a difference between an eye dropper working or not working,” he said.
In addition to verbal education at the counter, Mr Quigley suggests providing patients with a small ‘information sheet’, which can help patients retain the details provided. He adds that it’s also useful to “get to know the optometrist up the road” for ongoing patient referral.
An example here, Mr Quigley says, is the work done by Chemist Warehouse, which has launched ‘Optometrist Warehouse’ services.
“They have optometrists on the staff,” he said.
