Hair dye allergy

Hair dye and allergy

Hair dyes can cause allergy. The symptoms of this type of allergy can be so severe that hospitalization is necessary. Approximately half of the population in Denmark have at some point dyed their hair; 5.3% of these people have had an allergic skin reaction to the dye. Evidence suggests that only very few of those with an allergic reaction to hair dye seek medical treatment.

What does hair dye contain?

There are many hundred different colouring agents that can be used in hair dye. Some of these agents are known to provoke allergy. One such colouring agent is para-phenylenediamine (PPD), which has been used in hair dye for more than 100 years. Many colouring agents contain PPD and have either been proven to cause allergy or are suspected of doing so. The most commonly used are toluene-2,5-diamine, resorcinol, para-phenylenediamine (PPD), 4-amino-2-hydroxytoluene and p-aminophenol.

The amount of PPD used in hair dye depends on the colour required. PPD is most often used in the dark and red colours, but it is impossible to see from the colour if the hair dye will cause an allergic reaction.

There are several different types of hair dye. In permanent hair dye the colour penetrates the hair shaft and cannot be washed out. There are also semi-permanent hair dyes, which last for various lengths of time and which can be washed out. PPD is found in the colouring agents typically used in permanent hair dyes; however, substances similar to PPD are used in semi-permanent dyes.

Plant extracts are also used in hair colouring: henna is the best known. It is very seldom that henna causes an allergic skin reaction. Sometimes, henna is mixed with other hair-colouring agents, for example PPD or picramic acid, but it is still sold under the name of henna.

 

What are the symptoms of hair dye allergy?

Eczema, pimples, redness and blistering around the hair line and on the face and neck are all symptoms of an allergic reaction to hair dye. These symptoms are often accompanied by swelling, particularly on the forehead and around the eyes. The reactions usually appear within 24 hours of using the hair dye.

These allergic reactions may persist for several weeks or even months because the allergen in the dye remains in the skin. If you have an allergic reaction to a hair dye, you should seek medical attention. In rare cases the allergic reaction can be so severe that hospitalization is necessary.

Allergic reaction to hair dye ingredients (PPD)
Copyright: D@nderm dermatologisk atlas

More pictures of hair dye allergy

How widespread is hair dye allergy?

In 2003, a survey was carried out to investigate how many people in Denmark had experienced allergic reactions or allergic-like reactions to hair dye. Using the unique personal registration number (CPR number) that all residents in Denmark receive, 4000 people were randomly chosen and invited to an interview. Of those invited, 65.2% accepted. The survey showed that 74.9% of women and 18.4% of men had at one time dyed their hair, and 5.3% of them had experienced an allergic/allergic-like skin reaction to the hair dye. The average age for beginning to use hair dye was 16 years. (Søsted et al. 2005)

Every year in Denmark, around 250 cases of hair dye allergy are registered by a dermatologist. A survey by the Consumer Council suggests the extent of the problem is underestimated, based on information from dermatologists. In a relatively short period, 55 people were registered with hair dye allergy after being examined by a specialist, but only a small minority of these people had been referred to a dermatologist for allergy tests. This means that the vast majority of hair dye allergy cases, experienced by the consumer, are not registered. In the Consumer Council’s survey, most cases of hair dye allergy occurred with permanent hair dye.
 

Hair dye is among the most frequent causes of occupation-related allergic eczema seen in hairdressers. A study was carried out where participants without allergies dyed their hair with a permanent hair dye; 1107 participants dyed their hair once a week with a dye containing 0.5% PPD; they left the dye in the hair for 5 minutes before washing it out. After 6 months, 7.3% of the participants had developed an allergy to PPD. Another group of more than 500 participants dyed their hair once a month with a product containing 1.5% PPD; and they left the dye in the hair for 30 minutes before washing it out. In this group after 6 months, 1.3% of the participants had developed an allergy to PPD (Basketter 2006). The maximum permitted amount of PPD in hair dye is 6%.

These studies show that although the amount of PPD in hair dyes is below the maximum permit amount, it still poses a significant risk of provoking an allergy. With this in mind, it can be said that the more often you dye your hair, the greater the risk of provoking an allergy.

How is a diagnosis made?

A dermatologist makes the diagnosis using a patch test, also called a plaster test. Tests are made to check for allergic reactions to the different colouring agents. This may include the dye you have used to colour your own hair.

Read more about symptoms and diagnosis

Temporary tattoos are also known as black henna tattoos. Henna is mixed with PPD to produce the so-called black henna, which is far more effective for colouring than natural henna. The black henna is used in the temporary tattoos often offered to tourists both at the coast and in cities. These tattoos stay on the skin for several weeks and can lead to an allergic reaction. The allergy appears as eczema at the site of the tattoo, even though it may have worn off, or a strong allergic reaction may be experienced the next time the hair is dyed. It is not advisable to have a temporary tattoo unless you have reliable information about what the dye contains.

Legislation

Hair dye is classified as a cosmetic product and as such comes under the EU legislation that regulates the ingredients in cosmetics. For further information visit the Danish Ministry of the Environment’s website:

www.mst.dk (Available in english)

The EU Commission is currently reviewing all hair dyes to determine whether they are safe to use. The Knowledge Centre for Allergies (Videncenter for Allergi) is running a research project about hair dyes and their ability to cause allergic reactions. The project’s aim is to find out the frequency of hair dye allergy in Denmark along with finding out which hair dyes can be safely used and in what amounts to avoid provoking an allergic reaction. The overall aim is to prevent new cases of hair dye allergy.

Testing hair dyes before use

Many hair dye producers recommend in the directions for use testing the product on the skin, for example in the elbow crease or behind an ear, before using it to dye the hair.
To do this test, place a small amount of the product on one of the areas mentioned and wait up to 48 hours before washing it off.

Note the following points:

Different producers have different directions for use. It is not known if the test is sufficiently sensitive to show if someone who is healthy will have an allergic reaction after using the hair dye. A negative test cannot show with certainty that a person can tolerate the product. Hair dye contains strong allergy-causing substances that should not come into contact with the skin. Repeated skin testing with the hair dye before dying the hair can increase the risk of developing an allergy to the product.
 

Scientific publications

Søsted H, Johansen JD, Andersen KE, Menné T. Severe allergic reactions in 8 children. Contact Dermatitis 2006: 54:87-97

Søsted H, Hesse U, Menné T, Andersen KE, Johansen JD. Contact dermatitis to hair dyes in an adult Danish population - an interview based study. Br.J.Dermatol 2005; 153: 132-135.

Søsted H, Menné T. Allergy to 3-nitro-p-hydroxyethylaminophenol and 4-amino-3-nitrophenol in a hair dye.

Contact Dermatitis 2005; 52: 317-319

Søsted H, Rastogi SC, Andersen KE et al. Hair dye contact allergy: quantitative exposure assessment of selected products and clinical cases. Contact Dermatitis 2004; 50: 344-8.

Søsted H, Basketter DA, Estrada E et al. Ranking of hair dye substances according to predicted sensitization potenzy - quantitative structure-activity relationships. Contact Dermatitis 2004; 51: 241-54.

Søsted H, Agner T, Andersen K E, Menné T. Allergisk kontakteksem udløst af hårfarvning. Månedsskrift for Praktisk Lægegerning. Februar 2004; 82: 161-166

Søsted H. et al. 55 cases of allergic reactions to hair dye: a descriptive, consumer complaint-based study. Contact Dermatitis 2002:47:299-303

Schnuch A. et al. National rates and regional differences in sensitization to allergens of standard series. Contact Dermatitis 1997:37:200-209

Avnstorp C. et al. Acute fingertip dermatitis from a temporary tattoo and quantitative chemical analysis. Contact Dermatitis 2002:47:119-120

Marcoux D. et al. Sensitization to para-phenylenediamine from a streetside temporary tattoo. Pediatric Dermatology 2002:19:6:498-502.