One of my friends (let’s call her Bianca) came to me with a severe, red, itchy rash all up and down her legs. It looked like poison ivy (and it felt like it!) but it wasn’t.
It turns out that three days earlier she had worn a new pair of black leggings for the very first time. She wore these on a long run, came home, took them off, and was fine. But three days later she developed a severe rash.
What was the cause of her rash? She had developed allergic contact dermatitis, likely to the clothing dyes in her black workout leggings.
What is allergic contact dermatitis? And why would somebody develop an allergy to their workout gear?
Allergic contact dermatitis (ACD for short) is one type of allergic skin reaction. The most common type of ACD is due to poison ivy: your skin comes in contact with a particular substance, and then a few days later you break out in a rash. Other common causes of ACD are allergies to nickel in costume jewelry and fragrance additives in skin care products.
Many people don’t realize that you can also develop an allergy to the chemicals that are used in your clothing.
When it comes to workout clothing, the top triggers include dark clothing dyes, especially the blue dyes that are used in black clothing. Other chemicals, such as formaldehyde textile finishes, can also trigger allergic rashes, but in this post I'm focusing on allergy to clothing dyes.
I've been patch testing patients with mystery rashes for over 20 years, and allergy to clothing seems to be happening more frequently.
In this post, I'll discuss what textile dyes are, why someone might become allergic to them, and finally, how to avoid them.
What are textile dyes?
There are dozens and dozens of different textile dyes. These are the chemicals that are used to create different colors of clothing. If you walk into your local Target store, it’s actually pretty amazing. There are clothes for sale that cover the entire spectrum of the rainbow. In order to create these colors, you have to dye the fabric.
That's where clothing dyes, also known as textile dyes, come in. There are dozens of different clothing dyes, and a few of them are known to have a higher risk of triggering allergic skin reactions.
What are the colors that are most likely to trigger allergy? One of the top triggers is blue. These blue clothing dyes are used to make different colors of clothing, such as black, blue, purple, and other dark colors.
Other colors may also be a trigger, especially certain orange or red dyes.
Disperse Blue 106 and Disperse Blue 124 dyes are specific blue clothing dyes, and they're some of the top triggers of clothing allergy
You may have heard of these chemicals because we often use them when we're performing patch testing.
There are different categories of dye chemicals, and azo dyes are the usual culprits when it comes to allergic reactions. (Vat dyes are another type of dye, but rarely cause allergic reactions. That's why your Levi's 501 vat-dyed jeans are not likely to cause an allergic reaction.)
One subset of azo dyes are called disperse dyes. In terms of top triggers of clothing allergy, Disperse Blue 106 and Disperse Blue 124 are some of the top culprits. In fact, these are included in many patch testing series because of this increased risk of allergy.
Where are these disperse blue dyes found? One of the main places are black or blue synthetic fabrics. Surprisingly for many of my patients, they're usually NOT found in blue jeans. Keep reading for more information on fabrics and clothing.
Why would somebody develop an allergy to a clothing dye?
In many cases, we don’t actually know why somebody becomes allergic to their clothing dyes. But in the patients that I’ve seen over the last 20 years of treating textile dye allergy, I’ve seen a few common risk factors.
My friend “Bianca“ actually had several of these risk factors.
We know that sweating helps to leech the dyes out of the fabric, which means that your skin is potentially exposed to a higher dose of the clothing dye when you're sweating.
We know that clothing dyes are leached out more easily from synthetic materials such as polyester and nylon.
We know that all types of ACD are more common if there is prolonged contact with the skin, so time spent in contact with the fabric makes a difference.
We know that the closeness of contact makes a difference also. That’s why wearing tight leggings is more of a risk factor than wearing loose pants.
We know that friction is also a problem, because it damages the skin barrier and allows substances to come into closer contact with the immune system in the skin.
So to recap, Bianca had put on a new pair of workout leggings, had worn them on a long run where not only was the clothing in tight proximity to her skin, it was constantly rubbing against her skin. And she had worn these leggings for several hours while sweating heavily. All of these factors increased her risk of developing an allergy to her black leggings.
If I’m allergic to the dyes in my clothing, do I need to worry about new clothing only, or is it possible that my old clothing could also trigger a rash?
I always recommend washing a new item of clothing before you wear it, because there may be some residual dye that you can wash away. But – and this is a big point – you cannot wash away all of that dye. This means that once you become allergic to clothing dyes, it doesn’t matter if the piece of clothing is old or new. They can all potentially trigger allergic reactions.
How can I know if I’m allergic to clothing dyes?
The only way to know for sure is to undergo patch testing. This is a procedure performed in a dermatologist's or allergist's office, in which small amounts of the different textile dyes are placed on the back. The patches are worn for 2 days, and then 3 days later the back is examined to see if you’ve developed a rash at that area.
In some cases, though, patch testing may not be necessary. Sometimes the history of the rash so strongly suggests an allergy to clothing that we will go ahead and just recommend that patients avoid dark clothing dyes.
What types of clothing might make use of these dark blue clothing dyes?
First of all, remember that dark blue dyes can be used to create a whole number of different colors. They may be used to create black clothing, blue, purple, green, and other dark-colored clothing. This means that many colors may potentially contain blue clothing dyes.
In terms of types of clothing, my patients have reported many different types of clothing that have triggered problems for them. These are usually made of synthetic material such as polyester or nylon, but in a few cases even cotton has been a trigger.
These clothing items have included:
Leggings
Tights, stockings, or pantyhose
Sports bras
Swimsuits
Rash guards
Compression undergarments
Underwear
Wrinkle-free travel clothing made of synthetic material
Basketball uniforms
Cotton/polyester sweaters
Polyester blouses
And more
How can I limit my exposure to dark clothing dyes? What do you recommend to help me avoid these clothing dyes?
It can be tricky to limit your exposure to these dark dyes. My recommendations include:
If you buy new clothing, there’s a chance that it will have a higher dose of dye. That’s one of the reasons we always, always tell people to wash their clothing before they wear it for the first time. Washing clothing doesn’t remove the dyes completely (of course), but it may help remove some residual dye.
If you've developed a rash due to textile dyes, then you should try to avoid all dark-colored synthetic materials directly against your skin for at least eight weeks.
If your skin improves, then you can try re-introducing some of your items of dark-colored clothing. At that point, watch what happens to your skin. If that shirt or pair of pants is going to trigger a rash, it can take as short as 1 day or as long as 1 week.
We usually suggest trying out just one piece of clothing once per week. (Remember, it can take up to 7 days before the rash occurs.)
If it’s really hard to avoid dark clothing (your entire wardrobe is black!) then there are a few other strategies you can try.
Try to avoid really tight clothing against your skin
You can try wearing a light-colored T-shirt under darker shirts
Instead of tight pants, you might try looser pants
Some of my patients have worn thin white pant liners. These are similar to slips that you would wear under a skirt.
If you have to wear tight black clothing, you might be fine on a regular day, but you might have issues if you're sweating. That’s why some of my patients can wear dress clothing to work, but really have a problem with their workout clothes
The quality of the clothing may make a difference also. There are higher standards for clothing manufacturing, for example, in Europe and Japan. In contrast, I’ve worn certain traditional tunic tops from India, where by the end of the day I can actually see blue dye on my skin. The way in which it was manufactured makes the dye more likely to be leached out from the clothing.
Other types of dyes are fine, which is why most of my patients can wear blue jeans without any issues.
Can’t I just read labels to avoid these particular dyes?
Although clothing regulations are strict in terms of requiring labels that indicate the type of fabric used, there are no regulations that require information on the particular clothing dyes that are used in an item.
Will I ever be able to wear black clothing again?
For most of my patients, the answer is a resounding yes. But it definitely takes a bit of detective work. My patients who have been successful have usually reported back that there are maybe two or three items that they’ve been able to really pinpoint as a trigger for their rash. Their other black clothing seems to have been just fine.
The key is to first clear up your skin by using any medicated ointment prescribed by your dermatologist.
Also use the strategies listed above to try to avoid exposure to the dark clothing dyes.
Once your skin has cleared up with these two strategies, then you can start experimenting and really trying to pinpoint if any particular piece of clothing is acting as a trigger.
Most of my patients who have gone through this process are able to then start wearing certain pieces of black clothing again, although some of them require wearing T-shirts or pant liners underneath.
So, yes, you may actually be allergic to black clothing, but there are steps that you can take to improve your skin.
What happened for Bianca? I'm happy to report that Bianca was able to find her way back to a new pair of black leggings. These didn't cause any rashes, and she's now calling them her new favorites.