A TV doctor has urged people to pay attention to the warning signs (Image: Getty)
A red, itchy rash that develops after time in the sun can be easy to dismiss as prickly heat, but doctors warn it may point to another type of reaction. The issue can affect many people, and those taking certain medicines, including atorvastatin or naproxen, are advised to speak to a GP if symptoms appear.
TV doctor Dr Mark Porter highlighted the condition after being contacted by someone who believed they had prickly heat and had been told by friends to avoid sunscreen. Dr Porter said the description sounded more like polymorphic light eruption, known as PLE, rather than a simple heat rash.
Writing in a blog post for SAGA, the NHS GP explained that prickly heat happens when sweat glands become blocked and is more common in hot, humid weather. By contrast, PLE is a sunlight-related reaction and is frequently mistaken for prickly heat.
He said: “PLE is a sensitivity to sunlight, mainly the highly penetrative UVA component that can pass through clouds, water, glass and even some clothing. It causes an itchy, red rash that develops anywhere from a few hours to a few days after exposure, and the classic story is someone who notices it on the second or third day of their holiday in the sun.”
Dr Porter, who has nearly 40 years of NHS experience and received an MBE for services to medicine in 2005, said PLE usually appears symmetrically on both sides of the body. The rash is most often seen on areas including the chest, arms and the tops of the feet.
The doctor, known for presenting Radio 4 programmes and for his years on Good Morning Anne and Nick, said prevention centres on reducing exposure to UVA rays. He recommended using a good-quality sunscreen, preferably SPF 50 with a five-star UVA rating, and reapplying it every two hours. He also advised avoiding direct sun during the hottest part of the day, generally between 11am and 3pm.
Check your medication
The medical expert, who has also appeared on BBC’s The One Show, added: “In new cases, it’s worth checking whether recently started medications (such as some statins, doxycycline, thiazide diuretics or naproxen) could be triggering photosensitivity and discussing the rash with a GP.”
He said some dermatologists recommend beta-carotene supplements, but cautioned that the evidence behind them is limited, calling the science “shaky.” If someone chooses to try them, he noted the usual approach is about 15mg a day, starting a week before a sunny holiday and continuing until you’re back – or taking them during warmer, sunnier periods at home.
Because PLE typically starts in early adulthood – most commonly in women in their 20s and 30s – it would be less common for someone to develop it for the first time later in life. Dr Porter added that while certain medicines could potentially bring it on or make it worse, that isn’t guaranteed. Anyone concerned about symptoms should seek advice from their GP.
What are the signs and symptoms of polymorphic light eruption?
The NHS notes that the rash may:
- be itchy or feel like it’s burning
- be red or pink – this may be harder to see on brown or black skin
- have larger blotchy areas
- have small raised spots or blisters
It adds: “The rash can appear anywhere on the body, but is often in places that are not regularly exposed to the sun, such as the arms, legs or chest. A similar type of rash on the ears can cause small blisters that may be itchy or uncomfortable. This is called juvenile spring eruption.”
You can find out more about PLE via the NHS website here.
