Dying or colouring one’s hair has become a normal occurrence among both men an women. Maybe it is to get a new look, to hide your greys or a daring lifestyle change. But how safe are these hair dyes? Do we ever stop to think about the chemicals that are being applied on our hair and what it can do to us? Speaking to the Health Capsule Dr.Nayani Madarasingha, Consultant Dermatologist explained how allergies to hair dyes can occur after repeated use of such dyes. She also elaborated on how we can prevent such allergies.  

Types Of Hair Dyes
Kicking off with the types of hair dyes Dr.Madarasingha explained,“There are several types of dye.Temporary, semi permanent and permanent dye.How the dye works depends on the type, for example if you take a permanent hair dye the colour will be there for a longer period. But with the other ones the colour change will happen gradually, which is not an instant colour change, and it will fade away quickly.”  

Reaction To The Hair Dye
Moving on to the reaction to hair dyes she said, “In permanent hair dye and even semi permanent hair dye there is a risk of a user developing a hair dye allergy. There are two types of contact dermatitis. Contact dermatitis is when you are exposed to something you can develop a skin reaction to it. One type is called irritant contact dermatitis and the other one is allergic contact dermatitis. With hair dye both of these can occur.”  

Symptoms
“The symptoms can start immediately, within 48 hours or even later, after the application of the dye. Symptoms are not limited to just the scalp, they can also affect the hair margin, the ear, eyelids or even other areas like the back. Symptoms can be mild or severe.   

Mild symptoms include itchy scalp, redness, swelling. You can develop a severe reaction which can later lead to conditions such as eyelid swelling or hives. Very severe reactions which are known as anaphylaxis where your blood pressure can go down, can even result in death,” she said.  

Ammonia Is Not The Only Cause
Dr.Madarasingha explained that ammonia is not the only chemical hair dye users can develop allergic to. “One thing that people know about is ammonia which is in hair dyes and they think that when hair dye is ammonia free they can’t get allergic to it. However ammonia can cause irritant contact dermatitis. Most of the allergic contact dermatitis is due to a substance called PPD. This type of allergy usually develops with repeated exposure. Because when you are repeatedly exposed to an allergant it develops a reaction to that and the next time it is applied it will be more severe than the former reaction. That is why people who are using the same dye will develop the allergic reaction later in life. Therefore, although people think that the more familiar dye is the safer option it can actually worsen the allergic reaction.”  

“People also think that applying henna is completely okay. Natural henna is usually a red brown colour, not black. If it is black colour then it contains some amount of chemicals to give that black colourdness. For such things people can be allergic,” she added.  

Prevention
Dr. Madarasingha further stated, “If you develop an allergic reaction you have to immediately see a doctor, depending on the severity. If it is very severe you should consider it as an emergency and you will have to rush to the hospital. Even if it is a mild reaction it is advised to see a doctor. Afterwards you will have to avoid that particular dye.”

Explaining about the allergy test Dr.Madarasingha said, “There are a few PPD free dyes available in the market, however, even these PPD free dyes can cause allergies for some people.This is why anyone who is undergoing the hair colouring process should do an allergy test beforehand. To do this you have to apply the dye on the skin or the backof the ear and ideally leave it for over 48 hours. If there is no skin reddening swelling or small blistering then you can go ahead and colour your hair. Ideally, it should be done everytime you colour your hair and not just the first time. Even if the label says that the dye is PPD free or ammonia free you still have to do the allergy test and then dye your hair. In addition to this there are a lot of alternative hair dyes that are being marketed and even these things are not completely allergy free, because there are other chemicals that can be allergants.”  
“Even the person using the dye needs to take precautions, they have to wear gloves and it has to be done according to the instructions and it needs to be kept for the advised amount of time,” Dr. Madarasingha said.  

Advise
Dr.Madarasingha’s advice for those who dye their hair is as follows, “You have to do it according to the proper instructions and always do an allergy test. Some people who are allergic take the allergy tablet and then dye the hair, which is ill advised because the next time you dye your hair ,the reaction can be more severe and unpredictable. If you’re allergic you should avoid that dye and use a PPD free dye instead. Around 50% of people who are allergic to PPD can have allergies to other chemicals in the dye as well. Thus every time you dye your hair doing an allergy test beforehand is a must.”  

Other Complications 
Dr.Madarasingha further briefed on other complications that can occur when dying one’s hair, “ You can get contact leukodurma which is when you develop white patches on the skin. Some dyes can sometimes cause loss of existing pigment of the hair and some cause damage to the hair shaft.”