Almost half of UK adults (44%) have at least one allergy, according to charity Allergy UK. The numbers are rising, with hospital admissions for allergic reactions in England increasing by 12% between 2015-16 and 2017-18, from 25,167 to 28,177.
Professor Sheena Cruickshank, academic lead for public engagement at the British Society of Immunology, says developed countries are “seeing an increase in autoimmune diseases” such as allergies, which a 2010 study in the Clinical and Experimental Immunology journal supports. The big question is why.
In an autoimmune disease such as an allergy, the immune system reacts to a benign trigger it should ignore (such as pollen), resulting in inflammation. This causes symptoms ranging from swelling to mucus production, redness and soreness. In severe cases, allergic reactions can lead to anaphylactic shock, which can be fatal. Common allergies include hayfever, eczema, contact dermatitis, asthma and food allergies.
An allergy is not the same as intolerance, which patients may have, to certain foods for example, where someone may lack an enzyme required to digest a protein, such as lactose.
Is the hygiene hypothesis outdated?
Thirty years ago, the “hygiene hypothesis” was proposed as an explanation for rising levels of allergies. Scientists noticed that children from smaller families were more likely to suffer from hayfever than those from big families. They hypothesised this was because the former group had less exposure to infection-causing bacteria and viruses from older siblings, and that higher standards of personal hygiene might also have reduced rates of infection in childhood. They thought that suffering from fewer infections would weaken the immune system, therefore making people more susceptible to allergens later in life.
However, scientists now view the hygiene hypothesis as outdated.
Professor Cruickshank says research has moved onto “understanding how our immune system is working” and “understanding our interaction with the microbes that live in and on us, along with the microbes in our environment”. Most of these microbes don't cause disease, but contribute to the healthy functioning of the body.
Autoimmune disease is more common in the developed world, with populations moving from less developed regions to countries such as the UK showing an increase in autoimmune disease with each subsequent generation, says Professor Cruickshank. This “points to the environment” as a reason for the increase.
Amena Warner (pictured below), head of clinical services at Allergy UK and a clinical nurse specialist in immunology, says the hygiene hypothesis is “misleading” and has not led to better understanding of the rise in allergies. “You have to be mindful of hygiene – you don’t want infections being transmitted,” she adds.
Diet seems to play an important role in the development of food allergies, determining whether or not there has been “introduction of allergenic food into the early weaning diet of infants”, Ms Warner says.
It’s important that allergies to substances such as foods and medicines are properly diagnosed. “Patients need to be referred to a clinical immunologist or allergy specialist,” says Professor Cruickshank. Pharmacists should advise people to seek a referral from their GP, and not rely on someone who claims to be able to diagnose allergy through other means, she says. “There is no DNA test [for allergy] and tests that look for electrical vibrations also don’t work,” she stresses.
If you suspect a patient has an allergic condition like hayfever or eczema, you are well placed to support them. Professor Cruickshank says the first step is to “get a case history and focus on treatments that deal with the symptoms”.
People with hayfever can download an app, Britain Breathing, from the British Society of Immunology, to track symptoms. This may help them identify triggers, she says.
Managing allergy symptoms
Lila Thakerar MBE (pictured below), superintendent pharmacist at Shaftesbury Pharmacy in Harrow, says she is “definitely seeing more people coming to the pharmacy to ask for relief and advice about allergies”.
She believes the best way to help people to prevent allergic reactions and manage symptoms is to give appropriate treatment and advice, such as trying to stay away from pollen during the hayfever season.
Pharmacists can also download information for patients about allergies from the Allergy UK website.
Community pharmacists should ensure they have a full range of treatments for adults and children in stock and display them prominently during the hayfever season, which can start in March and end in September.
Terry Maguire, superintendent pharmacist at Maguire Pharmacy in Belfast, says his pharmacy has had a section in place for hayfever since mid-March. He has also been giving staff training in preparation for the hayfever season.
Ms Warner says appropriate treatments for hayfever include nasal allergen barrier balms or sprays (or petroleum jelly if people are looking for a low-cost option) and nasal saline douching to wash allergens out of the nostrils. She recommends long-acting antihistamines to be taken once a day, but advises steering patients away from the long-term use of decongestants, as they can result in a rebound effect when used on a regular basis.
Mr Maguire says it’s important to advise patients with asthma on how to use their inhaler properly. Pharmacists need to keep up to date with the latest treatments, but also “know their limits” regarding the support they can offer, he says.
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Pharmacists can advise patients with eczema about the importance of regularly applying emollients and moisturising creams to alleviate the typical symptoms of dry, itchy and cracked skin. They should recommend emollients “preferably with no scent or fragrance”, says Ms Warner. Some steroid creams and ointments are available over the counter.
Eczema and skin allergies can be linked to dry skin, she says. “When skin is damaged, [you may] get cracking of skin, which gets dry and itchy. When skin is cracked it becomes more susceptible to allergens,” she explains.
The underlying reasons for the increase in allergies over recent years are still the subject of research. But there are plenty of practical ways that pharmacists and their teams can help the growing number of people with allergies, whether that’s by signposting them to proper diagnosis or explaining the range of over-the-counter treatments available to help manage symptoms.