PMLE Sunscreen: What the Sun Allergy Sources Ask For
Type “sun allergy sunscreen” into a search box and the first page is a shop. Brand landing pages with a category filter named after the condition, product roundups, a few blogs that end in a buy button. What’s oddly hard to find is the boring bit underneath all of it: what did anybody actually test, on how many people, and how much sunscreen did they use? We went and read the sources instead of the shelf. Here’s what they say, and here’s the line we’re not crossing.
The short version: a PMLE sunscreen isn’t a regulated category, and no bottle is going to name this condition on the front. What the sources ask for is plainer than the marketing. DermNet’s general measures for polymorphic light eruption open with “Broad-spectrum 50+ SPF UVA/UVB sunscreen” [1] and the NHS asks you to “use sunscreen with a sun protection factor (SPF) of 50 or more” [2]. The UVA half is the part worth noticing, since DermNet writes that this “is primarily caused by either UVA (75–90%) or UVB light alone or UVA and UVB light concurrently” [1]. We opened two trials that brought the rash on deliberately and tested a sunscreen against it. Both came out the same way, and both are small: 12 people in 2008 [3] and 15 in 2022 [6], at laboratory application doses. Nothing here is a diagnosis and nothing here is a treatment.
What am we reading about when a page says “sun allergy”?
A specific named condition, usually. DermNet defines polymorphic light eruption as “a seasonal, acquired, idiopathic photodermatosis occurring in spring and early summer” [1]. Two of those words do the work: a photodermatosis is a skin condition set off by light, and idiopathic means nobody has pinned down the cause.
The nicknames are on the same page. DermNet lists them: “It is also known as polymorphous light eruption, sun allergy, sun poisoning, prurigo aestivalis, summer eruption/prurigo, or eczema solare.” [1] A 2018 review in Frontiers in Medicine calls it “the commonest photosensitive disorder” [4]. So “sun allergy” isn’t loose talk. It’s the everyday name for something with an ICD code, which DermNet gives as L56.4 [1].
That’s also where the trouble starts, because a nickname sticks to more than one thing.
The part a page like this can’t do
We can’t tell you whether you have this, and we’re not going to help you work it out. That isn’t politeness, it’s the shape of the evidence.
DermNet’s diagnosis section says it plainly: “Accurate diagnosis relies on the exclusion of other photosensitive conditions.” [1] The page then prints the list of conditions to exclude, seven of them: lupus erythematosus, porphyria, solar urticaria, Jessner lymphocytic infiltrate, photoaggravated atopic dermatitis, drug-induced photosensitivity, and seborrheic dermatitis [1]. Exclusion means ruling those out one at a time, which is clinic work rather than reading work.
The NHS makes the same point in a sentence you can hold in your head: “Polymorphic light eruption can be similar to heat rash (prickly heat).” [2] When a national health service writes that the ordinary version of this is easy to mix up with the ordinary version of something else, a page that has never met you has no business sorting it.
The NHS also names who does: “Your GP may be able to treat you or they may refer you to a skin specialist (dermatologist).” [2] Take that as the handoff, because we mean it as one.
One more boundary while we’re here. Both of our main sources carry treatment sections, we read both in full, and there is no treatment advice anywhere on this page. Steroids, light therapy, tablets, supplements: what’s in those sections is listed in the footnotes so you can see we didn’t skip past them, and it stays there. Choosing among them is a prescribing decision, and a sunscreen site has no standing in it. Everything below is about sun protection, which is the half we actually know something about.
Why spring is when people notice it
Because the trigger is the first strong sun of the year, and because skin adjusts as the season goes on.
DermNet’s clinical features start with the calendar: “Seasonal, occurring in spring and early summer and usually disappearing completely in winter.” [1] On timing after exposure it gives “Onset: occurs within several hours to 1–2 days after exposure to sunlight and is usually intermittent.” [1] Winter cases get their own line, and it isn’t mysterious: “Winter occurrences likely due to solariums (tanning facilities) or a holiday to a sunnier climate.” [1]
The fading is a named effect. DermNet describes “a phenomenon called the skin hardening effect where chronic exposure to sunlight leads to skin changes including increased melanin and thickening of the stratum corneum” [1], and adds that “Patients with PMLE can develop a tolerance during summer months.” [1] The NHS puts it in everyday words: “as the summer goes on, your skin becomes more used to sunlight and it’s less likely to happen” [2].
There’s a wrinkle in how the two describe where it turns up, and it’s worth flagging rather than smoothing over. DermNet says the “Distribution can include areas exposed to sunlight such as the arms, lower legs, V of the neck, and the chest”, and that “The dorsal hands and face are uncommon sites for PMLE possibly due to their chronic exposure to the sun and hardening of the skin.” [1] The NHS says 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.” [2] Opposite framings, same body parts. Reading them as compatible is our doing rather than either source’s, and the hardening idea is what makes them fit: hands and face get sun all year, arms and chest don’t.
The part of that we can act on is the calendar. The window both sources describe is spring and early summer, which starts earlier than the word summer makes it sound.
Nobody agrees on how common this is
They don’t, so we’re going to show you the spread instead of picking a number.
| The figure, as printed | Where we read it |
|---|---|
| “with an overall prevalence of 10-20%” | Abstract of the 2008 sunscreen trial [3] |
| “In northern Europe, it may affect 20–40% of women holidaying in the Mediterranean area, whereas in Australasian areas it is estimated to only affect between 1–5% of people.” | DermNet [1] |
| “occurs in 18% of Europeans”, which is part of a paper title in DermNet’s own reference list rather than a finding we read | Rhodes and colleagues 2010, as cited by DermNet [5] |
Note the second row isn’t a general population figure at all. It’s northern European women on Mediterranean holidays, which is a much narrower group than “people”.
Then it gets stranger, inside a single sentence. DermNet’s demographics line reads, in full: “Prevalence has been shown to be inversely related to latitude (highest in Scandinavia, the United Kingdom, and the northern United States; lowest in Australia).” [1] We’re quoting the whole thing on purpose. The first half says prevalence falls as latitude rises. The bracket then names Scandinavia and the northern United States as the highest and Australia as the lowest, which is the opposite direction. Quote either half on its own and you get a confident claim the sentence doesn’t support.
That makes three positions on one page, because five entries down its own bibliography is a paper whose title reads “Polymorphic light eruption occurs in 18% of Europeans and does not show higher prevalence with increasing latitude: multicenter survey of 6,895 individuals residing from the Mediterranean to Scandinavia.” [1] [5] Falls with latitude, rises with latitude, no relationship with latitude, all in one reference entry.
We can’t tell you which one wins. We didn’t read that paper: its PubMed record carries the title and the author list and no abstract, and the journal’s own page didn’t serve us the full text, which could as easily be a block on automated requests as anything else. So we’ve quoted a title as a title. It would be easy to write “18% of Europeans” as though we’d read the study, and that’s the sort of thing we’d rather not do. The honest summary of this whole section is that the numbers here are not settled, and none of them tells you anything about your own skin.
That’s the frequency axis. The other place the two references part company is smaller than a disagreement: one of them simply goes further. The NHS writes that “You’re more likely to get polymorphic light eruption if you’re under 40 years old, a woman or you have white skin.” [2] DermNet agrees on frequency and then keeps going: “Affects all races and all skin phototypes but higher prevalence in Fitzpatrick skin type 1” [1], and elsewhere “PMLE can be seen in all races and all skin types. It is more common in people with lighter skin. In darker skin types, the most common morphology is grouped, pinhead-sized papules.” [1] Fitzpatrick skin type 1 is the top of a six-step scale used for how skin reacts to sun; DermNet doesn’t define it on that page, so that gloss is ours.
Both are saying the same thing about frequency. The difference is where they stop: read quickly, the NHS sentence sounds like a white-skin condition, while DermNet adds that it happens in every skin type and looks different in darker skin.
The trials below make that gap concrete rather than rhetorical. The 2022 one recruited 15 people, of whom “Ten subjects were Fitzpatrick Skin Type III, 4 were Skin Type IV, and 1 was Skin Type I” [6]. Nobody at types V or VI was in it. So if your skin is at the darker end of that scale, the sunscreen evidence on this page was not gathered on people with your skin, and we would rather say that than let a percentage stand in for it. If you’ve ever had something waved off because it didn’t match the photo in the leaflet, that gap is the reason to take it to a person rather than to a search box.
Is this the same as a reaction to my medication?
No, and we’re not the ones drawing that line. DermNet puts “Drug-induced photosensitivity” in the differential diagnosis list for this condition [1], which means the reference itself files them as two things you’d want to tell apart.
Where they part company is the trigger. In the medication version, whatever reacts to light got there in a tablet or a tube. Here, the trigger is unidentified: DermNet describes the condition as “a delayed hypersensitivity reaction in the skin to unknown endogenous cutaneous photo-induced antigens” and states outright that “The photo antigen that triggers this response is currently unknown.” [1] Endogenous means it comes from inside the body rather than from a bottle or a tablet.
We wrote the medication side up separately, with the drug classes that appear on published lists and what one regulated label actually says about sunscreen, in our guide to photosensitizing medication and the sun. If you’re taking something and wondering whether that’s your story, start there rather than here. And if you’re wondering how you’d tell which one you’re dealing with: that’s the exclusion work DermNet says diagnosis depends on, so it’s a clinic question rather than a reading question.
Is there such a thing as a PMLE sunscreen?
Not as a category anybody regulates or tests you into. Products get marketed at this condition, and what the sources ask for is much plainer than that.
DermNet’s general measures are three bullets and no product names: “Broad-spectrum 50+ SPF UVA/UVB sunscreen”, “Sun protective clothing”, and “Avoid sunlight, choose shaded areas if outdoors and sit away from windows” [1]. The NHS version is equally unglamorous: “use sunscreen with a sun protection factor (SPF) of 50 or more and wear a sun hat and sun protective clothing when you are in the sun”, plus “apply sunscreen 15 to 30 minutes before going in the sun and reapply it every 2 hours and after swimming” [2]. Neither one asks for a filter type. Neither one asks for a special product.
What both of them do specify is the UVA half. DermNet’s causes section says the condition “is primarily caused by either UVA (75–90%) or UVB light alone or UVA and UVB light concurrently” [1], and the 2008 trial’s abstract opens the same way: it’s “mainly provoked by ultraviolet A (UVA) (320-400 nm) and to a lesser degree by UVB (280-320 nm)” [3]. Which sets up the sentence most likely to get quoted badly: “Most sunscreens protect predominantly against UVB and therefore fail to prevent PLE.” [3]
We read that as a statement about which number on the bottle carries the useful information, and that reading is ours rather than the paper’s. What it plainly isn’t is a statement that sunscreen doesn’t help: the same abstract’s conclusion goes the other way, and we’ll get to it. On a Korean label the UVA claim isn’t the SPF at all, it’s the PA rating, and we took that apart in our PA rating guide.
One more line from DermNet lands in territory we’ve covered before: “UVA can penetrate window glass and some sunscreens do not protect against it” [1]. Its own advice bullet says to “sit away from windows” [1]. We’re not going to re-explain the window glass part here, because our guide to sunscreen for driving already covers it.
Somebody did test this, twice
Researchers have brought this rash on deliberately, under lamps, and then tried to block it with sunscreen. We read two of those trials in the form we could get them, and both came out the same way.
First the scope, because “the only trial” is the sort of phrase you should have to back up. A PubMed search on 29 July 2026 for polymorphic or polymorphous light eruption together with sunscreen returned 94 records. Narrowing that to PubMed’s own clinical trial filter still returned 14, and its randomized controlled trial filter returned 10. We have not read them. That filter isn’t a census either: the 2008 trial below sits inside the set of 14, while the 2022 one, which is registered as NCT05320315 and calls itself randomized, does not. So these are simply the two we opened. They are not the only two and we make no claim that they’re the best two.
| Schleyer and colleagues, 2008 [3] | Duteil and colleagues, 2022 [6] | |
|---|---|---|
| Design, as written | “single-centre, open, placebo-controlled, intra-individual, comparative study” | “monocentric, double-blinded, randomized, untreated controlled intra-individual design” |
| People | 12 patients, of whom the rash could be provoked at all in 10 | 15 subjects, “13 women and 2 men, with a mean age of 44 ± 11 years” |
| Where on the body | Left and right “dorsal forearm” | Left and right chest, “10 × 15 cm2” each side |
| Light | “100 J/cm2 UVA and variable doses of UVB” | UVA only, “between 320 and 400 nm, peaking at 360 nm” |
| The product’s UV filters | Tinosorb M, Tinosorb S and butyl methoxydibenzoylmethane named as “UVA absorbing filters” | “octocrylene 8%, titanium dioxide 5%, butyl methoxydibenzoylmethane 3.6%, bis-ethylhexyloxyphenol methoxyphenyl triazine 3%”, plus “1% of ectoin” |
| Result | Rash at the placebo site in those 10, and “At the site with the active treatment none of these patients developed PLE” | “no positive PLE reaction was observed on the side of the chest treated by the test MD, whereas positive PLE reactions were triggered on the untreated side of 13 subjects”, p < 0.001 |
| What we actually read | The abstract only. The full paper is behind a download that served us an empty file | The full open-access paper |
Read the 2008 row carefully, because it’s easy to inflate. Twelve people took part, the rash could be brought on at the untreated site in ten of them, and it was those ten who stayed clear on the sunscreen side. It is not a finding about twelve out of twelve. Everything we’ve written about that trial comes from its abstract, since the publisher’s download link returned an empty file to us, so if you want its methods in full you’ll need to get past the same wall we didn’t.
Both papers are candid in ways worth carrying over. The 2008 abstract ends: “Further studies are needed to examine whether regular application of sunscreen under everyday conditions, especially in doses less than the tested COLIPA-norm, could be an equivalent alternative to UV-hardening therapy.” [3] The authors flagged the application dose themselves; that isn’t us reading between the lines. The 2022 trial used “2 mg/cm2” [6], which is the standard laboratory amount rather than a measurement of what comes out of a real tube. If that gap is new to you, we measured it out in how much sunscreen to apply.
The 2022 trial needs three more things said about it, and we’d rather say them than have you find them yourself. Its own authors write that “The weakness of this study is that this design does not allow the estimation of the relative contribution of ectoin versus UV filters in the prevention of PLE induced by UVA.” [6] In other words the product contained an extra ingredient and nobody can say how much of the result belongs to the filters. It was also paid for by the company that makes the product: “Sponsorship for this study and the journal’s Rapid Service Fee was provided by ISDIN SA (Barcelona, Spain)”, three of the authors are employees, one was an employee while running it, and two more are paid consultants [6]. And the untreated side wasn’t a clean sweep either, because “No PLE reaction was triggered on the untreated side for two subjects.” [6] None of that makes the result untrue. It does mean a manufacturer-funded trial of 15 people is not the same thing as settled.
Now the part that cuts against the shopping results, which is why we bothered with both. The advice repeated all over the first page of search results is to reach for a mineral filter for this condition. Neither tested product was mineral-only. The 2008 abstract names three UVA filters, and zinc oxide and titanium dioxide are not among them. The 2022 formula does contain titanium dioxide, at 5%, but listed alongside octocrylene, butyl methoxydibenzoylmethane and bis-ethylhexyloxyphenol methoxyphenyl triazine, plus the ectoin its authors say they cannot untangle from the rest. So we have nothing that ranks filter types against each other here, and we’re not implying a ranking in either direction. The 2008 abstract says as much in its own words: “The protection level of potent UVA-protective filters remains unresolved.” [3] Those filter names turn up in two other things we’ve written, a plain-language filter explainer and a Korean versus European comparison.
One number in the 2022 paper deserves a warning label. It describes its product as offering “a very high photo protection level (sun protection factor, SPF > 100 and UVA protection factor, UVA PF = 40)” [6]. That is not a PA rating and you cannot line the two up: the paper doesn’t say which method produced that figure, and the PA grades on a Korean bottle come from a specific in vivo standard. Our PA rating guide covers what the top grade does and doesn’t distinguish, and that’s the right place for it rather than here.
Am I supposed to stay out of the sun completely?
The sources ask for less sun rather than none, and one of them writes down what it costs to overshoot.
On timing, the NHS is specific: “stay out of the sun, especially between 11am and 3pm when the sun is at its strongest” [2]. That’s a clock instruction, and the forecast version of the same idea is the UV index, which we explained in our UV index guide. DermNet puts fabric on equal footing with the bottle, listing “Sun protective clothing” as its own general measure alongside the sunscreen [1], and reading a UPF number off a label is its own small skill, which we set out in our UPF clothing guide. The NHS puts numbers on the timing too: sunscreen goes on “15 to 30 minutes before going in the sun” and gets reapplied “every 2 hours and after swimming” [2], which is the same instruction we picked apart in our piece on whether you really need to wait 15 minutes.
Now the reason we won’t tell you to hide indoors from March to August. DermNet’s complications section lists four things. None of them is a skin problem: “Emotional distress”, “Anxiety and depression”, “Avoidance of activities due to concern for flares with sun-exposure”, and “If sun avoiding, there is a risk of vitamin D deficiency” [1]. Three of the four are about the life you stop living. The fourth is vitamin D, which is a question we looked at on its own terms in our piece on sunscreen and vitamin D.
So the whole of what this page can offer fits in four lines. Get real UVA protection rather than a big SPF number on its own, treat clothes and shade as equals rather than backup, watch the clock in the middle of the day, and take the rash itself to somebody who can look at it. None of that is a product recommendation, which is why there isn’t one here.
FAQ
Is there a bottle made for this that I should be hunting for?
Neither of the two clinical references we read asks for one. DermNet’s general measures say “Broad-spectrum 50+ SPF UVA/UVB sunscreen” and the NHS says “use sunscreen with a sun protection factor (SPF) of 50 or more”, and neither names a filter, a brand or a formula. Products are sold with this condition in the marketing, but there’s no regulated category behind that. The two trials we opened each tested one product against no product, so neither of them ranks formulas against each other, and neither tested a mineral-only sunscreen.
Is the SPF number the one I should be reading?
Not on its own. DermNet writes that polymorphic light eruption “is primarily caused by either UVA (75–90%) or UVB light alone or UVA and UVB light concurrently”, and the 2008 trial’s abstract says “Most sunscreens protect predominantly against UVB and therefore fail to prevent PLE.” SPF describes the UVB side. On a Korean label the UVA claim is the PA rating, so that’s the second number to find, and both sources ask for broad-spectrum rather than for a bigger SPF alone.
Should I expect this to ease off later in the summer?
The sources describe that pattern, though they describe it for the condition rather than for you. DermNet says “Patients with PMLE can develop a tolerance during summer months” and attributes it to a skin hardening effect involving increased melanin and thickening of the stratum corneum. The NHS says “as the summer goes on, your skin becomes more used to sunlight and it’s less likely to happen”. That’s a description of how the condition typically behaves, and it isn’t a prediction about your skin or a reason to skip sun protection.
Can I just stay out of the sun instead?
DermNet lists the costs of that in its complications section, which is where it also lists the rash. The four entries are emotional distress, anxiety and depression, “Avoidance of activities due to concern for flares with sun-exposure”, and “If sun avoiding, there is a risk of vitamin D deficiency”. Both sources ask for a mix instead: sunscreen, clothing, shade, and avoiding the strongest hours, which the NHS gives as 11am to 3pm.
How do I find out whether this is what I actually have?
By asking someone who can see your skin, and there isn’t a shortcut we can offer. DermNet says “Accurate diagnosis relies on the exclusion of other photosensitive conditions” and prints seven conditions that need excluding, including drug-induced photosensitivity. The NHS notes that this can look similar to heat rash, and says your GP may treat it or refer you to a dermatologist. A page like this one can tell you the condition has a name and a literature. It can’t tell you it’s yours.
Sources
Every source below was downloaded and read on 2026-07-29, in full except where entry [3] says otherwise. No named clinician is quoted anywhere on this page, and every quotation is from a page’s or a paper’s own text:
[1] Polymorphic light eruption, DermNet. Author credit as printed: “Author(s): Dr Prudence Gramp, Dermatology Department, Gold Coast University Hospital, Australia. Copy edited by Gus Mitchell. May 2022”. Classified on the page as ICD-10 L56.4. Quoted from the page’s own text: “Polymorphic light eruption (PMLE) is a seasonal, acquired, idiopathic photodermatosis occurring in spring and early summer.”; “It is also known as polymorphous light eruption, sun allergy, sun poisoning, prurigo aestivalis, summer eruption/prurigo, or eczema solare.”; “Prevalence has been shown to be inversely related to latitude (highest in Scandinavia, the United Kingdom, and the northern United States; lowest in Australia).”; “In northern Europe, it may affect 20–40% of women holidaying in the Mediterranean area, whereas in Australasian areas it is estimated to only affect between 1–5% of people.”; “Affects all races and all skin phototypes but higher prevalence in Fitzpatrick skin type 1.”; “PMLE can be seen in all races and all skin types. It is more common in people with lighter skin. In darker skin types, the most common morphology is grouped, pinhead-sized papules.”; “Patients with PMLE can develop a tolerance during summer months.”; “PMLE is a delayed hypersensitivity reaction in the skin to unknown endogenous cutaneous photo-induced antigens.”; “The photo antigen that triggers this response is currently unknown.”; “It is primarily caused by either UVA (75–90%) or UVB light alone or UVA and UVB light concurrently”; “UVA can penetrate window glass and some sunscreens do not protect against it”; “Seasonal, occurring in spring and early summer and usually disappearing completely in winter.”; “Winter occurrences likely due to solariums (tanning facilities) or a holiday to a sunnier climate.”; “Onset: occurs within several hours to 1–2 days after exposure to sunlight and is usually intermittent.”; “There is a phenomenon called the skin hardening effect where chronic exposure to sunlight leads to skin changes including increased melanin and thickening of the stratum corneum.”; “Distribution can include areas exposed to sunlight such as the arms, lower legs, V of the neck, and the chest.”; “The dorsal hands and face are uncommon sites for PMLE possibly due to their chronic exposure to the sun and hardening of the skin.”; “Accurate diagnosis relies on the exclusion of other photosensitive conditions.”; the differential diagnosis list, quoted complete: “Lupus erythematosus”, “Porphyria”, “Solar urticaria”, “Jessner lymphocytic infiltrate”, “Photoaggravated atopic dermatitis”, “Drug-induced photosensitivity”, “Seborrheic dermatitis”; the three general measures, quoted complete: “Broad-spectrum 50+ SPF UVA/UVB sunscreen”, “Sun protective clothing”, “Avoid sunlight, choose shaded areas if outdoors and sit away from windows”; the four complications, quoted complete: “Emotional distress”, “Anxiety and depression”, “Avoidance of activities due to concern for flares with sun-exposure”, “If sun avoiding, there is a risk of vitamin D deficiency”. Recorded here and deliberately not carried into the article: the page’s “Specific measures” section, which names topical and oral corticosteroids with doses, phototherapy, hydroxychloroquine, calcipotriol, afamelanotide, nicotinamide and systemic immunosuppressants; the diagnostic detail on biopsy findings, antibody testing and phototesting protocol, including the figure “60% of patients yielding a positive eruption”; and the outcome figures “60% of people see improvement or resolution over 15 years and 75% of people in 30 years”. Those belong to a clinician making a decision with a patient, and reprinting them under a sunscreen headline would put them in the wrong room. Note that this page uses British spellings and its own en dashes in number ranges, which we have reproduced. link
[2] Polymorphic light eruption, NHS. The page states “Page last reviewed: 10 June 2025” and “Next review due: 10 June 2028”. Quoted from the page’s own text: “Polymorphic light eruption can be similar to heat rash (prickly heat).”; “use sunscreen with a sun protection factor (SPF) of 50 or more and wear a sun hat and sun protective clothing when you are in the sun”; “apply sunscreen 15 to 30 minutes before going in the sun and reapply it every 2 hours and after swimming”; “stay out of the sun, especially between 11am and 3pm when the sun is at its strongest”; “You’re more likely to get polymorphic light eruption if you’re under 40 years old, a woman or you have white skin.”; “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.”; “as the summer goes on, your skin becomes more used to sunlight and it’s less likely to happen”; “Your GP may be able to treat you or they may refer you to a skin specialist (dermatologist).” Recorded here and deliberately not carried into the article: the page’s other self-care items, which name antihistamines and calamine lotion and emollients; its “Treatment” section, which names steroid tablets, topical corticosteroids, antihistamines and phototherapy, and which opens “Polymorphic light eruption usually does not need any treatment.”; and its three “See a GP if” criteria. We left the last of those out on purpose, because a list of thresholds is the fastest way to get a reader assessing their own rash against a checklist, which is the one thing this page is trying not to do. Scope: this is guidance written for the United Kingdom public and we have not treated it as a regulatory statement anywhere else. link
[3] Schleyer V, Weber O, Yazdi A, Benedix F, Dietz K, Röcken M, Berneburg M. Prevention of polymorphic light eruption with a sunscreen of very high protection level against UVB and UVA radiation under standardized photodiagnostic conditions. Acta Derm Venereol. 2008;88(6):555-60. doi: 10.2340/00015555-0509. PMID 19002338. What we read, stated exactly: the abstract on the publisher’s own page and the same abstract in the PubMed record, compared against each other character by character. We did not read the full paper. The publisher’s download link for it returned a three-byte empty file to us, so the Investigative Report itself is not something we have seen, and every sentence about this study anywhere on our page comes from its abstract. If a detail is not in the abstract, we have not written it. Three things about the text itself, since our quotations depend on them. First, the publisher’s page prints the first author as “Verena Schleye” while PubMed prints “Schleyer V”, and we have followed PubMed. Second, the publisher’s HTML carries a stray “¬” character inside three words, which appear there as “there¬fore”, “tetramethyl¬butylphenol” and “methoxy¬dibenzoylmethane”; PubMed prints all three as ordinary unbroken words, so we removed that character and changed nothing else. Third, the two versions punctuate number ranges differently: the publisher’s page prints “10–20%”, “320–400 nm” and “280–320 nm” with en dashes, PubMed prints the same figures with hyphens, and the hyphenated PubMed form is what we have reproduced. Quoted from the abstract’s own text: “Polymorphic light eruption (PLE), with an overall prevalence of 10-20%, is mainly provoked by ultraviolet A (UVA) (320-400 nm) and to a lesser degree by UVB (280-320 nm).”; “Most sunscreens protect predominantly against UVB and therefore fail to prevent PLE.”; “The protection level of potent UVA-protective filters remains unresolved.”; “single-centre, open, placebo-controlled, intra-individual, comparative study”; “containing methylene bis-benzotriazolyl tetramethylbutylphenol (Tinosorb M), bis-ethylhexyloxyphenol methoxyphenyl triazine (Tinosorb S) and butyl methoxydibenzoylmethane as UVA absorbing filters”; “photoprovocation was performed in 12 patients with a clinical history of PLE, on days 1, 2 and 3 with 100 J/cm2 UVA and variable doses of UVB”; “Prior to irradiation, placebo was applied to the right and sunscreen to the left dorsal forearm under COLIPA (European Cosmetic, Toiletry and Perfumery Association) conditions.”; “In 10 patients PLE could be provoked at the placebo site, with positive reactions in 90% of the UVA, 40% of the UVB and 90% of the UVA/UVB irradiated fields. At the site with the active treatment none of these patients developed PLE.”; “These data demonstrate that a sunscreen with effective filters against UVA and UVB can successfully prevent the development of PLE.”; “Further studies are needed to examine whether regular application of sunscreen under everyday conditions, especially in doses less than the tested COLIPA-norm, could be an equivalent alternative to UV-hardening therapy.” That final sentence is quoted in our article beside the conclusion rather than in this footnote, because a conclusion and its own limitation belong in the same breath. link
[4] Lembo S, Raimondo A. Polymorphic Light Eruption: What’s New in Pathogenesis and Management. Front Med (Lausanne). 2018;5:252. PMCID PMC6139322, PMID 30250845, published under a Creative Commons Attribution licence and read in full. One phrase is used on our page: “Polymorphic light eruption is the commonest photosensitive disorder”. A number we chose not to use: this review states that “New generation broad-spectrum sunscreens, with high sun protection factor for UVB (SPF), together with longer wavelength UVA protection, have been reported to confer total or partial protection in up to 90% of PLE patients”, attributing it to two earlier papers, one in the Lancet in 1993 and one in Archives of Dermatology in 1999. We could not open either one, and “total or partial” is a combined figure whose definition we cannot check, so that percentage appears nowhere in our article. Also recorded and not carried across: this review’s treatment sections, which cover first, second and third line management and which begin “The first line of treatment for PLE includes sun avoidance, sunscreens and topical corticosteroids”. We took the fact that sunscreen sits in first line management from our own reading of the two clinical references above rather than restating that sentence, since it names a prescription decision in the same breath. link
[5] Rhodes LE, Bock M, Janssens AS, et al. Polymorphic light eruption occurs in 18% of Europeans and does not show higher prevalence with increasing latitude: multicenter survey of 6,895 individuals residing from the Mediterranean to Scandinavia. J Invest Dermatol. 2010;130(2):626–8. PMID 19693026. What we have and what we don’t, stated plainly: this paper appears as the fifth bibliography entry on the DermNet page above, and we opened its PubMed record, which carries the title, the journal reference and the full author list. That record carries no abstract text. The journal’s own full text page returned HTTP 403 to our request, which is a status that servers commonly return to automated requests, so we are treating it as our failure to fetch rather than as any fact about the paper or the journal. So the only words of this paper we have seen are its title, and our article quotes it as a title and says so in the sentence where it appears. We are not reporting its methods, its population or its conclusion, because we have not read them. link
[6] Duteil L, Queille-Roussel C, Aladren S, Bustos X, Trullas C, Granger C, Krutmann J, Passeron T. Prevention of Polymorphic Light Eruption Afforded by a Very High Broad-Spectrum Protection Sunscreen Containing Ectoin. Dermatol Ther (Heidelb). 2022 Jul;12(7):1603-1613. PMID 35716331, PMCID PMC9276854, registered as NCT05320315. Open access, and unlike the 2008 paper we read this one in full. Quoted from the paper’s own text: “monocentric, double-blinded, randomized, untreated controlled intra-individual design”; “Fifteen subjects, 13 women and 2 men, with a mean age of 44 ± 11 years (range 25–57 years) were included in the study.”; “Ten subjects were Fitzpatrick Skin Type III, 4 were Skin Type IV, and 1 was Skin Type I”; “the output beam of the lamp comprised UVA light spectrum between 320 and 400 nm, peaking at 360 nm”; “octocrylene 8%, titanium dioxide 5%, butyl methoxydibenzoylmethane 3.6%, bis-ethylhexyloxyphenol methoxyphenyl triazine 3%”; “1% of ectoin”; “This formulation offers a very high photo protection level (sun protection factor, SPF > 100 and UVA protection factor, UVA PF = 40).”; “no positive PLE reaction was observed on the side of the chest treated by the test MD, whereas positive PLE reactions were triggered on the untreated side of 13 subjects”; “No PLE reaction was triggered on the untreated side for two subjects.”; “The weakness of this study is that this design does not allow the estimation of the relative contribution of ectoin versus UV filters in the prevention of PLE induced by UVA.”; “Sponsorship for this study and the journal’s Rapid Service Fee was provided by ISDIN SA (Barcelona, Spain).”; and the disclosure “Sonia Aladren, Xavier Bustos and Carles Turllas are ISDIN’s employees, Corinne Granger was employed by ISDIN when designing, running the clinical study and analysing the data. Jean Krutmann and Thierry Passeron are paid consultants by ISDIN.” That disclosure sentence prints one author’s surname as “Turllas” while the author list prints “Trullas”, and we have reproduced the disclosure as printed. The application amount we quote, 2 mg/cm2, and the treated area, “10 × 15 cm2” per side, are both from the methods. Two figures in this paper we chose not to use, because it attributes each to an earlier paper we did not open: a claim about broad-spectrum sunscreens conferring “total or partial protection in up to 90% of patients with PLE”, and a claim about a 1 mg/cm2 amount possibly helping in mild cases. Note on the UVA PF figure: the paper reports the number without naming the test method behind it, which is why our article says it cannot be set against a PA grade. link
What this page is: an editorial guide about sun protection, written by a sunscreen site. It is not medical advice, it cannot see your skin, and it contains no diagnosis and no treatment recommendation. Anything to do with what the rash is, or what to do about the rash itself, belongs to a doctor who can examine you.
Topics: Clinical Evidence · Swimming · Tinosorb · Winter & Snow · All topics
