Help, I reacted to my sunscreen!

I did a 11km walk up a volcano yesterday, for charity I hasten to add (go me) and like all good out-door girls I slapped on the sunscreen first.  I’ve been through this routine thousands of time without incident but this time my sunscreen fought back!

I didn’t notice at first but while driving back to my house some four hours after finishing the race I notices that I was very itchy around my collar bone area – an area I always burn so I have started to slap extra sunscreen on AND cover up more to avoid turning into a lobster.  The itching was scratched absent mindedly for a while until it clicked that this was no ordinary itch, this was lumpy, bumpy reaction skin!

I’d had a reaction to a skin care product.

 

Reacting to a sunscreen isn’t unusual as it is a product that is often applied to a large area of the body while you frolic around semi-naked in sand, sea and sausage sizzles (and ice cream but that didn’t rhyme very well).  While I wasn’t exactly doing any of the above I was still using a product while my body was under some degree of heat stress – product applied, shirt applied on top, then jacket, then walk up lots of hills and get hot and sweaty, then start removing clothing, then put it back on again after I finish and bake in my own sweaty coldness while eating a bowl of wedges and sour cream.  Yuummmmmm……

Basically I had occluded my sweaty skin, locking it under a layer of sunscreen and I had reacted badly to that.

The question is, is this a sign that I’m allergic to ingredients in that sunscreen or was it just one of those things?

Let’s have a closer look at the product shall we?

Was it in date?  Yes.

This is the first thing to check as if the sunscreen product has expired there is a chance that weird things will be happening to it including reactions between ingredients that could increase its irritation potential.  Ruling that out is helpful.

Was the product SPF tested and what was the SPF?

According to the label the product was SPF tested to a level of SPF 50 plus which is the highest you can get in Australia.  The product was tested to Australian standards.

Was the product stored properly?

Yes, pretty much.  We haven’t been to the beach this year and have kept this product in our kitchen cabinet applying it before dog walks and the like so I doubt it’s been affected by incorrect storage.

Did I apply it correctly?

Yes I did apply it to skin that didn’t have eczema or anything else at the time, I rubbed it in then popped my T-shirt back on.  The only thing here is that my skin in this area is a little sun damaged from the last 11 years of living in Australia so it is probably not my strongest of skin but neither was it ‘broken’.

So, to the ingredients:

Homosalate is a UV filter that is permitted for use up to 10% in Europe and 15% in the USA (Australia usually follows the EU laws) – it is at 10% in this formula as you can see.  There is a safety review for this ingredient here.  The safety review data in the link shows that this ingredient was found to be non-sensitising on human skin even when applied neat and left on occluded skin for five lots of 48 hour tests.   The filter is also photostable, oil soluble and specialised in UVB filtration.

Octocrylene is an ingredient often added into sunscreens to help improve spreadability (and therefore boost SPF) and also for its photostabilising power.  Octocrylene can be used to a maximum concentration of 10% and here it is used at 8%.  It

Octyl Salicylate is another UVB filter but this is also used because it helps to solubilise the Avobenzone (below).  This is another filter that has been extensively studied to see how much of it we absorb, how irritating it is and how stable it is.  All in all this is seen as a pretty safe sunscreen ingredient with no real concerns attached to it and no particular reason for me to suspect I’m allergic to it. Here’s the data.

Butyl Methoxybidenzoylmethane (also known as Avobenzone) is a commonly used UVA filter with maximum allowed levels of 3% in the USA 10% in Japan and 5% in Europe and Australia.  It is a pretty good filter but it does require steps to help maintain its photo-stability which is where the Octocrylene comes in.

Oxybenzone –  This is also known as Benzophenone-3 and is a UVB filter.  It can be used at a maximum concentration of 10% in Europe and Australia, 5% in Japan and 6% in the USA.   In this formula it is used at 2% so well within guidelines. This is another filter that has attracted much research but this time because of potential estrogenic effects – effects that might cause issue for the person using the product or for flora and fauna coming into contact with the ingredient down stream (pardon the pun).   Research concluded that around 1.9% of the applied dose absorbs percutaneously (through the skin) hence the safety margin for the filter.   The paper here also concluded that while the ingredient has a low acute toxicity (not likely to kill you) it can cause allergies in man (and women presumably) and so this may well be something I need to look further into for me.  Also I’m not fond of it as I do worry about the affects it has on our natural water courses.

See overview filter information here. 

But there’s more than just sun filters in a sunscreen.

Sunscreen labelling is such that you only have to list the actives due to this being a TGA product. This isn’t some big con, it’s just the way the law is at the moment, maybe it will change, maybe it needs to, maybe it doesn’t.  I am in two minds about that given what happened since cosmetic product started labelling everything. Anyway…..

The other ingredients listed are the preservatives.

Phenoxyethanol – there is always the potential that this has caused an allergy, plenty of people do react to it but most don’t and the levels used in a cosmetic product are usually safe for the majority of us.  I am a bit of a special case I guess as I handle this material more than most as it is commonly used in my cosmetic formulations.  It would be worth me seeing if I have become sensitised to it but the risk is fairly low.

Methylisothiazolinone – this is the second preservative and it is only allowed in concentrations up to 0.01% in Europe (not sure on Australian regs for this but it is likely to be the same).  That might sound tiny but I know that it does work at that level as this technology is amazing at killing bugs.  Sadly though, it also means it is quite amazing at being irritating if used incorrectly. The data reviewed for this ingredient by the EU is summarised here.   The link shows that this ingredient was reviewed again in 2014 after a rapid rise in rates of sensitisation found stemming from it. It is a chemical that I don’t use in my laboratory, mainly because people see it as too ‘chemical’ and rather use phenoxyethanol and simpler chemistry for preservation (yes I know, all of the above are big, scary chemicals).  It is quite possible that this is the culprit, that this triggered my reaction.  It is the chemical which throws up the highest level of concern for me, not least because I was using it in a leave-on product that I’d occluded AND got hot.  Three triggers in one.

So what next?

As tempting as it is to self-diagnose I am not going to do that any more than I have above.  What I will do is visit my doctor and get a referral for some skin tests.  This is important given my job and the likelihood of me coming into contact with these chemicals in a concentrated way.  My reaction was topical and was limited to where the sunscreen had touched – I had no reaction on my arms or feet for example.  That means that the reaction is not systemic – I didn’t have a full-blown allergic reaction to the product.

Lucky for me we are now moving into the cooler months where sunscreen is required less often so my likelihood of re-triggering a reaction like this is lessened.  In the meantime as I work out what is wrong I will adopt a much simpler approach to my personal care and will avoid the chemicals listed above that could be triggers (Methylisothiazolinone, Oxybenzone, phenoxyethanol).

Strangely enough when I looked around at other products I use I noticed that my daily moisturiser – an Australian Made Sensitive skin Sorbolene product ALSO contains the same preservatives as above. I hadn’t used this yesterday as I had forgotten to take it with me but it is possible that a daily slathering of this had primed me for a reaction.

So it is quite possibly NOT a reaction to my sunscreen after all, but a reaction to the preservative maybe?

Then again it is possible that this whole thing is just ‘one of those things’.

Time to see a dermatologist!

Stay safe and do keep using sunscreens. Please.

Amanda

 PS: I didn’t formulate this sunscreen and neither did I formulate the moisturiser I use each day.  I like to use other peoples products. It’s good market research.