I recently had someone ask me if a reaction to hair dye could kick off hair shedding. She said in part: “my hair was doing just fine until I tried a new hair dye. As soon as I put it on my scalp, it burned. That same day, my hair started falling out. And it has continued to shed for the past 3 months. From the research that I have done, it appears to my that I might have shedding due to telogen effluvium. But everything that I read indicates that this condition is caused by internal changes in the body. The hair dye would be an external change. But I swear that there was nothing wrong with my hair or scalp before I colored my hair. Is it possible that the hair dye kicked off this massive shedding?”
I have to admit that my first inclination was to agree with this woman and say that no, hair coloring can’t cause telogen effluvium since it is mostly caused by internal stress to the body like childbirth, stopping or starting medications, or crash diets. When this happens, the hair follicles go into the resting or shedding phase. And I wondered how using hair dye could inspire the same. It didn’t make a lot of sense to me.
However, curiosity got the better of me and I did some research on this. I found a 2001 study in which Italian dermatologists looked at this very issue. The doctors’ conclusion at the end of the study was that allergic contact dermatitis should be included in possible causes of telogen effluvium as the result of hair dye. In other words, the doctors felt that some of the women in the study had hair loss that was caused by an allergic reaction to the hair coloring. (Remember that the woman in the above scenario felt a burning sensation as soon as the color came in contact with her scalp.) The dermatologists suggested that perhaps that the inflammatory process from the allergic reaction might have triggered the shedding. Now, this does make sense to me. Inflammation is a phrase that comes up time and time again in literature concerning hair loss. In fact, many people suffering from hair loss also have a condition known as “burning scalp syndrome” in which the scalp turns red or pink and becomes painful due to the inflammation that comes from those changing hair follicles that I just mentioned. I suppose it is possible for this to also happen before the shedding starts.
So to answer the question posed, most specialists will deny that hair dye can kick off a long round of shedding. But a study that I found contradicted this line of thinking. Therefore, it’s my opinion that an allergic reaction to the dye (but not the dye itself) can contribute to shedding and hair loss in some people. And frankly, at the end of the day, I’ve learned not to question any one’s hair loss. If you are seeing troubling hair loss, that’s obvious evidence that something is going on and you likely do have a trigger somewhere. You just have to find it. And if you noticed the hair fall starting shortly after having a painful or bad experience with the color, then that makes a lot of sense to me.