How common are allergies to sunscreen?

“25 percent of all people are going to be allergic to chemical sunscreens.”

This statistic was published in a beauty magazine recently.

Contemporary experiments and surveys have been done on the topic of sunscreens as an allergen. Here are the conclusions of some of them…

“Of 23,908 patients patch tested, 219 (0.9%) had sunscreen coded as an allergen source. “

“Allergy to sunscreen represents a small proportion (< 1%) of allergic contact dermatitis reactions in North America”

“[Allergic contact dermatitis] to sunscreen was found to be very uncommon (0.8%).”

There are more papers on this subject, but all their results have a common trend. None of them estimate rates of allergies to sunscreens or sunscreen chemicals for the general population to be even close to 25%.

Most found an allergy to sunscreen’s prevalence among patients with conditions like photosensitivity to be less than 1%.

That’s patients, people who had some kind of skin reaction and went to a doctor — for the general population the prevalence is probably even lower.

Analysis of the Prevalence of Allergic Contact Dermatitis to Sunscreen: A Cohort Study
By Katie Beleznay, Gillian de Gannes, Sunil Kalia
Published January 1, 2014

In this experiment they reviewed 1,527 patients who were tested against 70 allergens.

23 of those 1,527 patients were further tested against sunscreen chemicals. Of those, only 4 patients reacted. 8 other additional patients of the 1,527 tested patients reacted to oxybenzone.

The quoted 25% likely came from a misframing like this, the prevalence of allergy they found is not 4 out of 23 patients (17%). It’s 12 out of 1,527 patients (0.8%), and likely lower for the general population.

“The prevalence of positive patch test reactions to sunscreen chemicals or a sunscreen product was 12 of 1,527 (0.8%) for all patients referred to our clinic for patch testing.

Other data indicate that among patients referred for patch testing, the prevalence of allergy to active sunscreen ingredients is low, likely less than 1%.”

Patch Test Reactions Associated With Sunscreen Products and the Importance of Testing to an Expanded Series
By Erin Warshaw, et al.
Published July/August, 2013

“Of 23,908 patients patch tested, 219 (0.9%) had sunscreen coded as an allergen source…the most commonly affected areas were the face and exposed sites…The top 3 most frequent allergens in sunscreens were benzophenone-3 (70.2% for 10% concentration, 64.4% for 3% concentration), DL-alpha-tocopherol (4.8%), and fragrance mix I (4.0%).”

Here we find some of the allergens in the sunscreens weren’t the sunscreen chemicals, but fragrances and a form of Vitamin E.

Sunscreen Allergy: A Review of Epidemiology, Clinical Characteristics, and Responsible Allergens
By Erin Warshaw, Elyse Scheuer
Published March, 2006

“The prevalence of allergy in the general population to sunscreen agents is unknown. Among individuals referred for patch testing, the prevalence of allergy to active sunscreen ingredients is low, probably less than 1%.”

“2,715 patients referred for presumed photosensitivity disorders from 1983 to 1998. Sixty-two patients (2.3%) exhibited photoallergic reactions, and of these reactions, 65% were due to UV absorbers.”
The prevalence described here isn’t 2.3% or 65%. It’s 65% of 2.3%, that’s 1.5%.

Contact and Photocontact Sensitivity to Sunscreens: Review of a 15-year Experience and of the Literature
By Silvia Schauder, Hellmut Ippen
Published 1997

Looking at data from between 1981 to 1996, 402 patients with suspected clinical photosensitivity, 80 (20%) demonstrated a reaction to 1 or more UV absorbers.

What to keep in mind is that these are patients with suspected clinical photosensitivity and are not representative of a general population.

Some of the sunscreen chemicals used in this study, like para-aminobenzoic acid (PABA), isopropyl dibenzoylmethane, and Enzacamene, are no longer commonly found in sunscreens due to frequent skin reactions.

Allergies to sunscreen is a real occurrence, but it’s very likely not as prevalent as 25% of all people.

If you experience: burning, stinging, lasting redness, welts, hives, or any other signs of a reaction – you should consider discontinuing use of the sunscreen or skincare formula.

Consider testing new sunscreens or skincare on a small patch of skin before using them more liberally.

Medical care may be out of reach for many in the US, but a dermatologist or allergist can work with you to help pinpoint what ingredients are causing your reactions.

When is “Free From” just Fearmongering?

“Free from” claims need to be relevant to the formula to be, well relevant.

“Free from” claims are often attached to products and formulas that normally wouldn’t contain the ingredients. This is when “free form” marketing can turn into fearmongering.

Let’s look at story about KFC to understand why.

KFC or Kentucky Fried Chicken is a global fast-food chain that is famous for its fried chicken.

In 2012, KFC ran advertisements in Canada claiming that their chicken was “hormone free”.

Suddenly, some people worried. Were there hormones in other brands’ chickens? Was KFC healthier, safer, and “cleaner” because their chicken was hormone free?

The Canadian Food Inspection Agency, dedicated to the safeguarding of food, plants, and animals in Canada, responded:

‘Products cannot be labelled or advertised as “hormone free” as it may mislead consumers to believe that the meat in question does not contain any hormones…all meat, poultry and fish products contain naturally occurring hormones.’

What that statement says is that chickens naturally have hormones, so it can’t be “hormone free”.

KFC clarified that they meant that they served chicken “that’s raised without hormones.”

They meant they didn’t supplement their chickens with hormones, which implied that other brands did.

But since 1963 in Canada, you can’t give chickens hormones.

Turns out in reality all chickens in Canada are actually “raised without hormones.”

This happens a lot in skincare, in a few different ways.

Irrelevance: We’ll see products like facial oils say “Free from sodium lauryl sulfate”, when sodium lauryl sulfate is not a common or necessary ingredient in a facial oil formulation.

Too Broad: We’ll find claims like “Free from fragrance” claims on products where ingredients, like plant extracts impart a scent.

Inaccuracy: “Free from formaldehyde” claims are often attached to products that contain ingredients that release formaldehyde at safe levels to preserve the formula.

Undefined: “Cruelty free” is not a defined term. Some brands take it to mean they haven’t tested the product on animals. It might mean the finished product wasn’t tested, but the ingredients were. Or a contractor or authority did. Because it’s not a standard, it’s up to the brand to define it. Some organizations have created logos and definitions that brands use, but customers must verify the standards used and its claims.

“Free from” claims might have begun as a useful and quick declaration to potential customers and users.

“Free from alcohol” would be useful for a parent buying a mouthwash for their child.

“Free from animal-derived ingredients” would be useful for someone who is vegetarian or vegan.

Like almost any product messaging, “free form” statements have mostly turned into more real estate for advertising and marketing.

Often by implying a product is “free from” it implies it is superior and in today’s market “cleaner” than its competitors.

Ultimately this trend may end up being worse for the beauty and skincare community as they’re left anxious and confused.

Gua Sha and our Biases

When I was a boy, any time I would get a sore throat or a cold, my mom would pull out a soup spoon and scrape it against the back of my neck.

Growing up, this was what I associated with care. This is what I associated with healing, and this is what I learned was my mom saying to the universe “No, my child will not be sick and in pain.”

Later, I would learn that this was gua sha. A common practice in the Chinese community.

It is hard for me to separate gua sha from my mother’s love, her care, and the culture she gave to me.

I do not know if it worked, but I know my mom believed it did.

One day in the distant future, I will look at a stone used for gua sha and it will hit me.

It will hit me that all those things that my mother gave me are gone, and that all I hold in my hands is just a stone – and it cannot connect me to a culture and its traditions anymore.

But for now, it is something that I may not understand – but it is not something that I disparage without making an attempt to understand it.

At the end of the day, if there is no magic, if there is no effect, there’s still culture in that stone. And inside that culture hides an entire history and knowledge.

Many things we will never have the opportunity to understand, because it is hidden behind another language – 你很多人都看不懂.

Communication in the sciences is not as universal as we would think.

The walls of language still separate understanding. As English-speakers we are biased to believe that all knowledge and facts are written in English.

But they are not.

Recently, the International Union for Conservation of Nature missed the Taiwanese populations of the fairy pitta birds in its survey – because the numbers were not published in English.

There is research investigating these treatments and practices – it is just that I, and many of you, cannot read it.

The drug artemisinin was discovered in a mixture of herbs used in traditional Chinese medicine to treat malaria.

And there’s entire countries with a different perspective on care.

So, it is hard for me to judge – I just do not know enough, most of it I just can’t read.

Below is a screenshot of a paper that reviewed 437 papers on gua sha from 1994 to 2007. I cannot read any of them.

Understanding the world is a lot like watching a mystery show sometimes. Each episode we learn a bit more, and start building a bigger picture.

Only at the end of the show do we see the full picture, but sometimes the show gets cancelled on a cliff-hanger too.

But recognize that there are many shows, all on at the same time, saying different things.

And many, many, many of those shows we will never see – if they are not in our language.

So, I am not asking you to believe in gua sha, or any traditional medicines from different cultures, but I am asking you to maybe take a pause and recognize the biases that being inside an English-speaking culture creates.

At its core, gua sha might just be a stone and it might just be massage, and the secret might have been feeling loved and cared for.

But I do not know.

Accessibility is Aesthetic

Making your content more accessible is one of the easiest ways to increase your audience.

While Instagram has offered new tools to offer different ways to engage with content, there’s still a lot of easy steps we can choose to make our content even better!

For the past few days, I’ve been reaching out to my audience through my stories to learn about their needs. The Polls sticker is a great way to collect feedback.

You can view the process by tapping the ‘Accessibility’ stories highlight on my Instagram profile.

People have also shared with me many resources and tips that I’ll pass on to you:

  • Add descriptions of images in our captions. For example a photo of me right now I could describe as, “Stephen is sitting in front of his computer, his hair is long and unwashed. He seems stressed but happy that he is at home.

  • We can also describe or transcribe our posts by filling in the Alt Text found under ‘Advanced Settings’ when making or editing a post.

  • We can caption or transcript our videos. Using static, not animated text is easiest to read. Use a contrasting background for the text so it stands out from the video.

  • There are free fonts like this one, Atkinson Hyperlegible, that are designed for easy reading.

  • Small, swoopy, and animated text might be fun, but it can be hard to read.

  • #NotCapitalizingOurHashtags makes text to speech tools read out each letter individually.

  • For font colours, we want to make sure that we have good contrast between the text colour and the background colour. is a tool that will allow you to measure and adjust your text and background contrast.

  • When sharing Grid Posts to our Stories, it is not always clear that the square is tappable. A simple “Tap Below to Read” is all you need to add!

  • For those that can share links in their stories, the Swipe Up action will be hidden if the story has a light background. A simple ‘Swipe Up to Read’ in a contrasting colour can help.

  • Remember blogs? I know this type of image with text post is popular now on Instagram, but web text allows readers to adjust font size, change fonts, use browser reading modes, and it is easier for screen readers.

    I leave a link in the caption to a blog version of my posts. This one can be found at

  • For big blocks of text, left-aligned text is easier to read.

  • Try to break down chunks of text into smaller sections of three.

  • Big blocks of italicized text can be hard to read, they’re best used for emphasis. Consider bolding too!

For other tips on accessibility tap through to @Access_Guide_, right on Instagram!

On Making Amends: Creating a Space for Recovery, Healing, and Peace.

I want to share with you some lessons I’ve learned on how to create a space for healing and peace for people that have been harmed.

In my life, like any person, I have spoken and behaved in ways that have harmed people around me and the people I care about.

“Like any person” is crossed out, because I wanted to use that sentence to share a lesson I have learned. Harms we have enacted are not caused by society, culture, or something greater than us. They may be the soil that the harm we caused grew in, but deferring the blame to something greater than us is a way to unburden ourselves of the weight of creating harm.

To use a personal example, I had harmed a friend when speaking about a concern I had with myself. I did not recognize that I was upholding an abuse structure in our culture that had harmed my friend in the past. The abuse structure is bigger than I am, but I acted as a conduit from it to my friend. I am responsible for the harm I caused. Seeing someone uphold an abuse structure, intentionally or not – strikes fear into the people who were exiled or harmed by it.

I have learned that apologies can be a trap. We must recognize, as the people who have harmed, whether the desire to make amends is for us or for the people that we have harmed. Sometimes a person who has been harmed needs time and space. That is often the only thing within their power to control in response to harm. Offering an apology can sometimes destroy their power and control, and preclude that response.

An apology can act as a reminder of harm, before the person who was harmed is ready to confront and process the pain.

An apology can act as a ticking clock because it can force a person who is harmed to respond, and to respond within a polite time frame.

An apology is a burden because the person who was harmed must hold the weight of the apology and also perform forgiveness.

I have learned to recognize that because fear and confusion are common responses to being harmed, distancing is sometimes the only protective action that feels safe.

I have learned if forgiveness is offered, it is important to understand that forgiveness is not a resetting of relationships or closeness. Forgiveness is not a way to move backward, it is a way to move forward – and sometimes it means moving forward apart.

I have learned that forgiveness can be given by the person who was harmed, to themselves. And in that process, forgiveness can be given to you by a person unburdening themselves of the conduit that brought harm into their life.

Sometimes forgiveness means that the person will walk away from you, and that means sometimes we only need to provide them a path to do so clear of obstacles.

It takes care, time, and empathy to recognize that we are not always the source of healing.

How Marketing Numbers Without Context Can Boost Beauty Claims: Percentages and Fractions Need Context

The rising use of data and science in beauty marketing has led to an increase in percentages, fractions, and statistics. When it comes to percentages and fractions, it is extremely important to understand what they mean.

Often, important contextual information is left out. This can have the effect of boosting the claims brands make about their products.

Let’s look at something simple to begin with, how fractions can be converted into percentages – and vice versa.

2/4 is 50%

250/500 is also 50%

2 and 250 are numerators, while 4 and 500 are the denominators.

This numerator is how many parts of the whole, and the denominator represents the whole.

This comes into play when we look at claims like 90% of people agreed that For’real Serum increased skin dumplingness. What we’re missing is the context of the denominator.

90% could be 9 out of 10 people, or 900 out of 1000 people.

9 out of 10 people is a small sample and probably subject to some sort of bias. If 900 out of 1000 people agreed though, that would be more convincing.

This issue with lack of denominator context is also pervasive in claims using “bioavailability”, “penetration”, “absorption” and “conversion”. These are often claims of comparison – but they’re usually missing the context of how and what they’re being compared to.

How tall is Ranbir if we’re told “Ranbir is 20% taller”? We don’t have the information to know! But we can figure it out if we’re told “Ranbir is 20% taller than the average American firefighter in 2020”

In a similar vein, what does “20% more hydration” mean? We don’t have the information to know! But we have an anchor if we’re told “20% more hydration compared to before use”.

Let’s look at some beauty relevant examples…

40 times more skin penetration…

An important piece of information that’s missing is how was this determined? Is the way that this was determined applicable to the way that their customer will be using it on their skin? Often this data comes from models of skin (things are designed to mimic some aspect of skin, but are not skin), and in vitro (something that isn’t the living, whole organism) or cells. An ingredient might penetrate 40 times more into an individual dermal skin cell floating inside a plastic dish of nutrients over 2 days…but we are not giant dermal skin cells floating inside a plastic dish of nutrients.

What really matters is how the ingredient penetrates human skin that’s part of a living, functioning, whole human person. As well, it’s more relevant if the ingredient or product is used in a way that mimics how we would use it. If penetration increases after 40 minutes of being in a microwave oven…I would argue that information probably isn’t relevant.

90% skin “bioavailability”…

Claims like these often have the same issue as the previous claims we just looked at — like how a measurement was made. But often they also lack another type of context. What’s being measured?

What these claims insinuate is that 90% of what you’re applying to the skin will be “bioavailable” to the skin. But what’s often missing is the context that the 90% is usually a measure of what is “bioavailable” after skin penetration (or the skin model, cell, or in some cases a piece of gel or paper).

Let’s say you have 100 red balls of various sizes.

You shake them through a sieve.

8 red balls have passed through the sieve.

We have 8 red balls out of the 8 balls that fell through the sieve (8/8, 100%).

Is that 100% “bioavailability”?

We need to remember that we started with 100 red balls.

So out of those 100 red balls we started with, only 8 red balls passed through the sieve (8/100, 8%).

So is the “bioavailability” 8% or 100%?

Well, you’re using (and paying for) the 100 balls, so I would say the 8% is the number that’s more relevant.

Note: I have “bioavailability” in quotes because in terms of skincare it’s not well defined. In pharmacology, bioavailability is the amount of a taken drug that reaches the bloodstream.

“Bioavailability” is often used in the marketing of  nutritional supplements, but the pharmacology definition doesn’t really make sense because how a nutrient gets used or absorbed can also depend on a person’s current nutritional and physiological state.

The meaning of “bioavailability” in skincare becomes even harder to pin down. It can sometimes mean the amount of an ingredient that reaches the lower epidermis – but there’s no strict or widely accepted definition nor is there a standard way to measure it.

Often “bioavailability” in skincare is just a marketing term to make a product sound more unique and effective compared to its competitors.