Is Your Hair Dye Causing an Allergic Reaction? Here’s What You Should Know

Many people love the confidence boost that comes with freshly colored hair—but for some, that new look may come with an itchy, irritated scalp. If you’ve noticed redness, itching, or irritation after dyeing your hair, especially darker shades, you might be experiencing an allergic reaction.

Meet the 2025 Allergen of the Year: Toluene-2,5-Diamine Sulfate

Every year, dermatologists highlight a “Contact Allergen of the Year,” and for 2025, it’s toluene-2,5-diamine sulfate—a common ingredient found in many dark hair dyes. While the name is a mouthful, the symptoms it causes are all too familiar: itchy scalp, redness, or irritation after coloring your hair.

What Should You Do If You React to Hair Dye?

If you suspect your hair dye is causing a reaction, don’t ignore it. There are allergy-friendly hair dye options, but the first step is seeing a board-certified dermatologist. We may recommend patch testing, a safe and simple way to test for contact allergens using a panel placed on your back.

Once we identify what you’re allergic to, we can help you find safe hair dye alternatives and develop a personalized plan so you can continue coloring your hair without the discomfort.

You don’t have to suffer through reactions or give up hair dye altogether. With expert help, you can protect your scalp and keep your hair looking beautiful.

✨ Think you’re allergic to hair dye? Contact us to schedule a patch test and get to the root of the issue.

Want the transript for this video instead? Did you know that your hair dye could be causing an allergic reaction? I'm Dr. Schneider. I'm a board certified dermatologist. Let's talk about why every year dermatologists name a contact allergen of the year, and for 2025 that allergen is toluene two five diamine sulfate. So what is that? Besides a very long word, this chemical is commonly found in hair dyes, especially in darker shades.

If you are getting a red, itchy or irritated scalp after getting your hair dyed a darker color, then this could be one of the culprits you're getting a reaction to. Hair dy. Don't ignore it. Get help from a board certified dermatologist. There are allergy friendly options for people who are allergic to hair dyes.

The first step is to see a board certified dermatologist so we can evaluate you and decide if you might benefit from patch testing, which is where we do allergy testing on the back to see what you could be allergic to. Once we identify the allergen, then we can come up with safe alternatives for you to use to keep your hair beautiful.

Have you had a reaction to hair dye? Let me know in the comments and don't forget to hit that like IT button for more derm tips.