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A couple of decades ago, many of us hadn’t heard of nut-free lunch policies, EpiPens and ‘free from’ foods, but the relentless rise in the rate of allergies means these are all now commonplace.
Allergies range from mild to severe, with hayfever at one end of the spectrum and anaphylaxis at the other. The immediate nature of many allergic reactions places pharmacists at the centre of their management, as quick and easy access to treatment is very important.
Despite a significant rise in awareness of allergies in recent years, plenty of confusion still surrounds them. The mechanism behind allergy is complex but is best described as the negative reaction that the body has to a particular substance.
Very often these substances are foods (e.g. egg, shellfish and nuts), although a person can be allergic to pretty much anything. Common allergens other than food include Latex, bee and wasp stings, and a number of medicines (e.g. antibiotics, NSAIDs, aspirin, chemotherapy drugs).
Symptoms are broad and range from a runny nose, sneezing, skin rashes and worsening of asthma and eczema, through to the swelling of the lips and throat that is seen in severe reactions.
Anaphylaxis (also known as anaphylactic shock) can be caused by an allergy and is a medical emergency. People who are known to be at risk of anaphylaxis should be advised to carry an adrenaline auto-injector at all times.
There are no accurate statistics regarding allergy incidence as, for example, many people don’t go to their GP or pharmacist if symptoms are mild. What is known is that the rate of allergies has been rising fast, particularly in children and especially in the Western and developed world.
In the UK, 45 per cent of adults and 38 per cent of children reported allergy symptoms in the past 12 months – one of the highest rates in the world.1 Serious allergies are on the rise with a seven to 10-fold increase in anaphylaxis in the past two decades.
There are various theories as to why allergy incidence is increasing so rapidly. These include:
• Hygiene hypothesis. This argues that, if we are not exposed to bacteria and endotoxins in early childhood, our immune systems don’t develop as they should and therefore overreact when exposed to allergen challenges
• Excessive use of antibiotics
• Air pollution
• Eating more processed food
• Increase in stress
• Insulation and double-glazing, which have created more of an allergy challenge within people’s homes.
“The environment in which we live has changed,” says Holly Shaw, a nurse adviser at Allergy UK. “We know there is evidence that early exposure to lots of microbacteria has a protective effect [from allergies].”
The rate of allergies has been rising fast particularly in children
Eczema (atopic dermatitis) is a disease characterised by a faulty skin barrier, which causes the skin to lose moisture and allows infection to enter, resulting in inflammation, intense itching, redness, dryness, blistering and scaling. The itching can promote scratching and skin damage, leading to cracked, weeping skin, which, in turn, creates more irritation and can cause the sufferer to become trapped in an itch-scratch cycle.
Allergic dermatitis also causes irritation, itching and inflammation. Unlike irritant dermatitis, which is caused by repeated exposure to harsh chemicals, allergic dermatitis involves an immunological response and requires a sensitisation period. Key triggers are either contact (e.g. plants, cosmetics, fabric, jewellery) or environmental (e.g. food, sunlight and medicines).
Also known as nettle rash or hives, urticaria is characterised by raised red weals on the skin that may itch or cause a burning sensation and are often accompanied by angioedema. Urticaria has various causes and only around 20 per cent of cases are connected with allergy. Other possible triggers include infection, physical pressures and food intolerance.
Polymorphic light eruption
Polymorphic light eruption (PLE) is a common skin problem that usually occurs during exposure to the first strong sunlight of the year or while on a sunny holiday. It is not clear why certain individuals are affected by PLE, although it is thought to involve a delayed reaction to an allergen produced in the body in response to ultraviolet (UV) radiation. The problem usually subsides as the skin adapts to stronger UV levels.
Insect bites and stings
Most insect bites and stings clear up within 24 hours but systemic reactions involve the airways and require immediate medical attention as they can lead to life-threatening anaphylaxis.
Pharmacists and their teams are uniquely placed to help people with allergies avoid allergens and comply with their treatment regimens. With allergy costing the NHS an estimated £1 billion a year, effective treatment could have a significant impact.2
It is particularly important that pharmacists target compliance, as low levels of adherence can lead to conditions caused by allergies (e.g. eczema and asthma) becoming worse, or even increase the risk of anaphylaxis.
“GPs won’t necessarily have time to ensure patients understand how best to use their medicines, so pharmacists can play a key role in helping [patients] understand how to use or take their medicines correctly, whether it is a tablet, inhaler or nasal spray,” says Shaw.
Pharmacists are also well placed to help eczema patients, for example, find which treatments are best for them, says Dr Emma Wedgeworth, consultant dermatologist and British Skin Foundation spokesperson. “Emollients are absolutely key and helping to find a product that suits an individual, as well as educating people on appropriate quantities to apply, is essential. Avoiding harsh cleansing products can also help maintain the skin barrier.
“Mild topical steroids such as 1% hydrocortisone available over the counter can also make a significant difference if used appropriately.”
“People are more likely to take medicines for allergies if they know which symptoms they can treat and how to use the medication effectively. It is important they have easy access to information about possible side-effects, how to take allergy medication, and when to seek help,” says Knut Shroeder from Self Care UK.
Emma Wedgeworth says she has seen at first hand the negative effects of poor compliance with asthma and eczema medication. “One of the major barriers to effective treatment is steroid phobia, which often perpetuates poor control of eczema. It is so important that all healthcare professionals involved with eczema patients – particularly pharmacists – feel comfortable with the use of topical steroids so they can instil confidence in their patients.” Something to bear in mind at the height of the summer allergy season.
Antihistamines are the mainstay of allergy management. They work by blocking the action of histamine, a chemical mediator released by the body as part of the immune response. Histamine widens blood vessels to increase the supply of white blood cells to the affected area. This results in inflammation or oedema in the surrounding tissue and can also cause narrowing of the airways. Histamine release will result in itching and irritation.
Antihistamines are most effective in advance of allergen exposure but can still be highly beneficial if taken during a reaction. In addition, antihistamine creams can sometimes be used to soothe insect bites and stings (although are not generally recommended), while nasal sprays and eye drops containing azelastine can relieve irritation in the nose or eyes. Nasal antihistamines have the advantage of a rapid onset of action, although they do not control as many symptoms as oral antihistamines.
Intranasal corticosteroid sprays or drops alleviate and prevent both immediate nasal allergy symptoms (e.g. sneezing and watery discharge) as well as late phase symptoms, such as congestion, irritation and sinus pain, which occur later in the allergy cascade as a result of additional chemicals released from mast cells. Corticosteroids suppress inflammation in the nasal passages by reducing mast cell activity.
Cromoglicate works by blocking histamine release during an allergic reaction by stabilising mast cells. It should ideally be administered before contact with the allergen and can take several weeks to have full effect, so is preventative in nature. Patients who are particularly troubled by eye symptoms, for example, should therefore be encouraged to persevere with treatment. Sodium cromoglicate nasal sprays can help to alleviate hayfever symptoms in children, for whom nasal corticosteroids are unsuitable.
Decongestants provide short-term relief from nasal congestion associated with allergic rhinitis. They work by increasing vasoconstriction in the blood vessels of the nasal passages, which results in reduced inflammation and mucus production. Intranasal decongestants containing ephedrine or xylometazoline should not be used for longer than five to seven days as prolonged administration can lead to rebound congestion.
Saline nasal washes or sprays are an effective alternative to decongestants that can be used all year round and are safe for use in children. They help to wash allergens out of the sinus passages and provide gentle relief from nasal irritation and congestion. In addition, sterile saline eye drops are a simple, gentle and effective alternative for dealing with seasonal allergic conjunctivitis.
Practical advice to help allergy sufferers avoid allergens includes:
House dust mites
• Choose wood or hard vinyl floor coverings instead of carpet
• Fit roller blinds that can be easily wiped clean
• Clean cushions, soft toys, curtains and upholstered furniture regularly, either by washing or vacuuming
• Use synthetic pillows and acrylic duvets
• Use a vacuum cleaner fitted with a high efficiency particulate air (HEPA) filter
• Wipe surfaces with a damp, clean cloth, as dry dusting can spread the allergens further
• Concentrate effort on controlling dust mites in the areas of your home where you spend most time.
• If you can’t permanently remove a pet from the house, keep it outside as much as possible or limit it to one room, preferably without carpet
• Do not allow pets in bedrooms
• Wash pets once a fortnight and groom dogs regularly outside
• Wash all bedding and soft furnishings where a pet has lain
• If visiting a friend or relative with a pet, ask them not to dust or vacuum on the day you are visiting as this will stir up allergens in the air
• Take an antihistamine one hour before entering a pet-inhabited house.
• Keep your home dry and well ventilated
• When showering or cooking, keep internal doors closed to prevent damp air from spreading through the house and use extractor fans
• Do not dry clothes indoors, store clothes in damp cupboards, or pack clothes too tightly in wardrobes
• Deal with any damp and condensation in your home.
• Stay indoors when the pollen count is high
• Avoid drying clothes and bedding outside when the pollen count is high
• Wear wrap-around sunglasses to protect your eyes from pollen
• Keep doors and windows shut during mid-morning and early evening, when there is most pollen in the air
• Shower, wash your hair and change your clothes after being outside
• Avoid grassy areas, such as parks and fields.
• By law, food manufacturers must label clearly foods that contain anything that is known to cause an allergy. By carefully checking the list of ingredients, a person should be able to avoid an allergic reaction
• When eating out at a restaurant, do not rely on the menu description alone but check what allergens a dish may contain
• Avoid places where there is a chance that different types of food could come into contact with each other, such as buffets or bakeries.
Allergies are often not taken particularly seriously in comparison to other physical illnesses. However, children with food allergies have been shown to be more anxious than those with insulin-dependent diabetes4, while higher levels of depression and anxiety have been reported in children with eczema.5
Learning and development can also be affected as memory and cognitive ability in individuals with eczema is significantly worse during the allergy season – particularly bad news for young people in the exam season, who may even see their grades affected due to the effects of their allergies.
Researcher Lavanya Diwaker says pharmacists need to rethink recommending medicines that cause drowsiness. “One of the biggest concerns with hayfever is that children take these medications during the exam season and drop grades because they are drowsy. There should be more focus on non-drowsy medication in such cases,” she says.
Allergy testing can be controversial. There are only two ways you can test for allergies, says Holly Shaw, and that is either through an IgE blood test or through a skin prick test. “What these two tests do is check for the presence of IgE antibodies in the blood or if there is a specific skin inflammation in response to an allergen.”
She warns against using any allergy testing kits that work differently, as they are not accurate and could lead to the unnecessary avoidance of food or other substances. “Hair testing and other alternative forms of testing are not scientific. They have been shown in the past to show multiple intolerances, leading to people removing the food from their diet and losing a lot of those nutrients.”
Allergy testing is also not necessary for mild conditions, she says. “Most patients will self-report they have hayfever, for example, without ever having an allergy test. You can do tests to find out which pollens are causing it but that won’t make any difference to the way the condition is self-managed and won’t make it any easier to avoid grass when someone goes to the park, for instance.”
New treatments such as allergen immunotherapy and better avoidance measures continue to be researched, offering hope to people with severe allergies. Baby weaning advice is also being reevaluated to determine how best to protect children from developing allergies in the first place.
Community pharmacists and their teams will continue to be an important point of information for their customers as advice and treatment options in the field of allergy change and grow. Because one thing is for sure: allergic disease represents a significant and expanding health problem worldwide, but particularly in the UK.
1. House of Lords: Science and Technology Committee: Sixth report: allergy. London. House of Lords 2007
2. Gupta R, Sheikh A, Stractan DP et al. Burden of allergic disease in the UK: secondary analyses of national databases. Clin Exp Allergy 2004: 34: 520-6
3. Diwakar L, Cummins C, Liford R et al. Systematic review of pathways for the delivery of allergy services. BMJ Open 2017
4. Cummings AJ, Knibb RC, King RM et al. The psychosocial impact of food allergy and food hypersensitivity in children, adolescents and families: a review. Allergy 2010; 65:933-45
5. Hon KL, Pong NH, Poon TCW et al. Quality of life and psychosocial issues are an important outcome measure in eczema treatment. J Dermatolog Treat 2015: 26:83-9