Are you allergic to summer?

Times

24-06-2025

You know how it is — you wait all year for some decent weather and then two heatwaves come along in quick succession. Worse, when the sun is out in full force you remember that it's not always as pleasurable as you'd imagined it would be.
'We see a lot of rashes, reactions and heat-related illness at this time of year,' says Dr Dan Baumgardt, a GP and senior lecturer in the school of physiology, pharmacology and neuroscience at the University of Bristol. 'Some of these are related to seasonal temperature changes and some are due to changes in exposure to products, fabrics and chemicals that are more common in the warmer months.'
The impact of hot weather can prove fatal, and the UK Health and Security Agency (UKHSA) recently warned people to keep tabs on the colour-coded warnings it jointly issues with the Met Office. For the coming weekend, these have tilted back into red for the southeast of the country, with temperatures expected to surpass 30C. And while red and amber alerts signify the greatest heat risk, yellow weather warnings, the lowest alert threshold, can also be significant. According to the UKHSA many of the 1,311 heat-associated deaths last summer occurred during yellow heat health alert periods and more deaths occurred during heat episodes early in the summer season.
But what else do we need to be aware of during the summer months? Here our experts give advice on some of the common — and more unlikely — seasonal ailments.
The result of getting so hot that the brain's thermostat fails, this leads to dangerous overheating. It is an emergency and requires urgent medical intervention. 'People don't take the risks of heatstroke seriously enough yet it can have potentially very serious outcomes,' Baumgardt says.
Symptoms According to the NHS, symptoms of heat exhaustion include having hot, flushed and dry skin, a headache, nausea, dizziness and confusion. A body temperature over 40C, a change in skin colour, changes in heart or breathing rate, being very thirsty and displaying rapidly worsening responsiveness are clear warning signs.
How to treat and avoid it 'It is important to stay hydrated and to avoid excessive alcohol intakes,' Baumgardt says. 'Simple steps such as wearing appropriate clothing and avoiding exercise or hours in the garden at the hottest times of the day are also important.' If someone is displaying signs of heat exhaustion and can be cooled down within 30 minutes — by removing clothing, rehydration with a sports drink or cool water and cooling their skin with cold packs — the NHS says they may not require medical attention. 'But if they don't improve after cooling attempts, call 999 as soon as possible,' Baumgardt says. 'People can develop seizures and risk death if they are not treated immediately.'
Rashes and stings are a common hazard but gardeners, hikers and fruit pickers are at risk of more serious skin reactions that occur as a result of phytophotodermatitis, sometimes called 'margarita burn'. Dr Zainab Laftah, a consultant dermatologist at HCA The Shard Hospital in London, says this occurs when skin comes into contact with light-sensitising botanical agents called furanocoumarins that are present in some plants and sap, which then interact with ultraviolet A (UVA) light. Giant hogweed (Heracleum mantegazzianum) is a prime example but other plants can cause similar reactions. 'Handling citrus fruits, celery, parsley, figs and wild parsnip can trigger this in some people,' Laftah says. Wild carrot (Daucus carota) and common hogweed (Heracleum sphondylium) can also be problematic.
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Symptoms 'Affected areas become acutely red and nasty blisters or linear streaks appear within 1-2 days of exposure,' Baumgardt says. 'It can take several weeks for the area to heal and might leave permanent pigmentation damage.'
How to avoid and treat them 'Wearing gloves and protective clothing while gardening, washing skin thoroughly after plant contact, and avoiding sun exposure immediately after handling potentially reactive plants will help reduce the risk,' Laftah says. Applying sunscreen can help to reduce the light exposure, which might lessen the severity of a reaction. Take care when strimming hedgerows and borders as you can inadvertently come into contact with plant sap. Applying a cold compress to the affected area is recommended. 'You may need topical anaesthetics to avoid infection, so speak to a GP or pharmacist,' Baumgardt says.
'There are a lot of nasty things lurking in rivers, lakes and ponds,' Baumgardt says. 'We get an upswing in ear infections and rashes when people swim outdoors at this time of year.'
One specific parasite you might encounter is the larvae of avian schistosome cercariae, which often take up residence in water snails. 'These parasites can burrow into your skin and cause swimmer's itch, or cercarial dermatitis, a nasty allergic reaction to the parasite,' Bamugardt says. Several recreational lakes in the UK have had to close in recent years due to the presence of the parasite and researchers from Liverpool School of Tropical Medicine and Budapest Semmelweis University, reporting in Parasites and Vectors journal, warned that with the increase in popularity of outdoor swimming, the prevalence of swimmer's itch is probably under-reported in the UK.
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Symptoms An itchy rash and skin redness appears within 24 hours. Nasty red bumps then begin to erupt and that can last for several days.
How to treat and avoid it 'Be aware that exposed flesh when swimming in open water does carry risks, so cover up as much as possible and always wear a wetsuit,' Baumgardt says. 'With swimmer's itch, infected skin usually heals in a week without serious complications, although if secondary bacterial infection occurs you will need antibiotics, so see a GP.' A fragrance-free emollient (moisturiser) or anti-itch cream can be helpful when itching is at its worst.
Removing the protective layer of socks means that feet come into direct contact with a range of unfamiliar materials and fabrics in footwear, which can cause reactions that result in bumps and rashes. Among the most common footwear allergens, according to researchers at George Washington University, are dyes, leather, rubber, metals and adhesives in shoes. Heat, friction and sweat, along with foot deodorants and sprays, can also increase the risk of contact dermatitis on the feet and between the toes in some people.
'Allergens can trigger allergic shoe contact dermatitis, especially when heat and moisture break down the skin barrier,' Laftah says. 'Wearing well-ventilated shoes made of natural material, avoiding prolonged use of plastic or rubber-based shoes, and using moisture-absorbing socks is recommended.'
Symptoms Exposure can cause chronic or acute swelling, blisters or cracks in the skin, a burning sensation, itchiness or pain.
How to treat and avoid it 'Contact dermatitis clears up if you remove the materials or substances causing the problem,' Baumgardt says. 'Emollients or moisturisers from a pharmacy might help to ease the condition while the rash is present.'
If the symptoms persist and you cannot detect the cause, see a podiatrist or GP for a prescription of topical corticosteroid cream. 'Patch testing can also help identify specific allergens and provide guidance on appropriate shoe wear,' Laftah says.
Sunscreen reactions are mostly a reaction to specific chemical ingredients in a product. 'Among the most common irritants are chemical UV filters such as oxybenzone, avobenzone, octocrylene and PABA (para-aminobenzoic acid),' Laftah says. 'These reactions can present as allergic contact dermatitis or photoallergic dermatitis, where UV light activates an allergic response to a compound in the sunscreen.'
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Symptoms Irritant contact dermatitis is more common in people with underlying skin conditions such as eczema. It causes redness and a mild stinging sensation at the site of application. It can sometimes take 24 hours to appear. An itchy, blistering rash where you apply the sunscreen could indicate an allergy to one of the chemicals in the product. Photoallergic dermatitis usually appears on the face, arms, back of hands, chest and lower neck, and may resemble eczema or sunburn.
How to treat and avoid it 'Switching to mineral-based sunscreens containing zinc oxide or titanium dioxide, which are less likely to cause irritation or reactions, is a good idea,' Laftah says. 'Avoid fragrances and preservatives in sunscreens which may also contribute to these reactions.'
Reactions can be more severe if sunscreen is used with some medications or other topical creams and lotions, so check what you are using.
Margaret Kelman, head of clinical services for Allergy UK, says that some people develop rashes on exposure to sand at the beach. 'It can be down to the fact that sand is drying and abrasive or a combo of sand and seawater and a reaction to sunlight,' she says. General debris and insects in the sand can also cause problems. 'Abroad there are parasites and creatures such as sand flies can lead to bites and rashes,' Baumgardt says.
Symptoms Skin can become inflamed, sore and itchy.
How to treat and avoid it 'Apply moisturiser as well as SPF to provide an extra barrier and wash or shower as soon as you get back home,' Kelman says. 'Sit on a beach towel and wear longer or more protective beach clothes.' If skin flares up, over-the-counter topical steroids might be needed.
Chlorine is added to pools as a disinfectant to keep them clean and safe for swimming. In itself, chlorine is not an allergen but it can have a drying effect on the skin, potentially exacerbating dermatitis and eczema. 'Chlorine can also irritate the lungs in people with asthma,' Kelman says. 'Eyes can be irritated by the chemicals.'
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Symptoms Itchy red skin or hives (itchy bumps), difficulty breathing and sore, red eyes are all signs of chlorine irritation.
How to treat and avoid it 'If your skin is affected, put on moisturiser in addition to sunscreen before getting in the pool, shower as soon as you get out and then reapply,' Kelman says. 'Wear goggles to protect your eyes from the chlorine and use your inhaler when needed if you have asthma and are spending more time in or near swimming pools.'
Pollen-induced hay fever affects as many as 13 million people in the UK — the majority of whom are allergic to grass pollens in the summer months.
Symptoms Sneezing, coughing, a runny or blocked nose, as well as red, itchy or watery eyes.
How to treat/avoid it 'Speak to a GP, who will help to create a treatment plan,' Kelman says. Options include antihistamines such as fexofenadine, nasal steroid sprays such as Nasonex (both available on prescription) and sodium cromoglicate eye drops (such as Opticrom). Nasal saline washes such as the NeilMed Sinus Rinse Kit (£21.99, boots.com) are also worth trying. 'They can be useful to help rinse allergens that may be present in the nasal passages,' Kelman says.
Government weather health alerts: https://ukhsa-dashboard.data.gov.uk/weather-health-alerts
Allergy UK: allergyuk.org