Hair dye sensitivity testing: a critical commentary

Abstract

SummaryAlthough the large majority of users do not experience adverse skin reactions to hair dye products, a minority do. Most serious among these are allergic skin reactions, commonly to p-phenylenediamine and its derivatives. The consumer or hairdresser is expected (by the manufacturer) to limit the chance of expression of allergy by conducting a 'sensitivity test', which should provide the consumer with an alert for possible allergic reactivity. However, a self-conducted consumer test can only be useful if it meets a number of important criteria, including evidence that the test protocol works, that it can and is likely to be used successfully by the consumer or hairdresser, and that it does not present a significant health risk (e.g. an increased risk of developing allergy). In short, as with any in vivo test, the benefit must outweigh the risks. In formulating such a test, it should be determined in advance what are the acceptable levels of specificity (correct identification of negatives) and sensitivity (correct identification of positives). It is our view that any hair dye sensitivity test, whether supplied by the hair dye manufacturer or a third party, should be able to answer these questions.Key words: cross-reaction; hair dye; p-phenylenediamine; sensitivity test.There is an extensive body of clinical literature showing that allergic contact dermatitis caused by hair dyes is a significant, probably increasing, occupational and consumer health problem (1-4). Allergy to hair dye is not a new phenomenon, having been reported for many decades (5, 6), and hairdressers are commonly high on the list of those with occupational dermatitis (7-9). Investigation of those with dermatitis in that industry shows that a significant number have hair dye contact allergy. Among consumers, the currently available evidence suggests that although >90% of hair dye users do not experience allergic reactions, several per cent may do so (1-4, 7). However, of concern for the future is the apparent intensity of sensitization to p-phenylenediamine (PPD) that is occurring in children (10).It is of significance that almost all of the hair dye work has been completed with just a single marker hair dye allergen, PPD. Indeed, the present evidence suggests that although PPD might not be responsible for all cases of hair dye allergy (11, 12), the fact that it cross-reacts so well with other commonly used hair dye allergens [e.g. toluene-2,5-diamine (PTD) and the aminophenols] makes it an effective marker of the majority of hair dye allergy problems (13,14). This also is consistent with the evidence from in vitro T lymphocyte stimulation studies, where two-thirds of T cell clones reactive to PPD also responded to PTD, as well as being consistent with the results from in vivo models (15-18). However, it has been shown that there are some individuals with hair dye allergy who do not have a positive response to PPD (11,12,18). Recently, a survey of oxidative hair dyes on the Swedish market concluded that the use of a number of potently sens...

Factors associated with p‐phenylenediamine sensitization: data from the Information Network of Departments of Dermatology, 2008–2013

“…In our study population, the pretest was performed by only 3.6% of the patients, and was not statistically associated with the PPD PT result (Table ). Although no firm conclusions can be drawn from these data, and these pretests are generally (not just in our study) utilized very infrequently , we agree with the statement of the DKG and others that such testing should be avoided, to minimize skin contact with highly potent allergens outside a medical context .…”

“…Self‐administered hair dye pretests, often also referred to as ‘self‐tests’ or ‘sensitivity tests’, which are recommended by some hair dye producers, have also been suggested to constitute a risk factor for sensitization to PPD . In order to collect information about these (proven or putative) risk factors for PPD sensitization, six PPD‐related questions were added to the Information Network of Departments of Dermatology (IVDK) questionnaire from 2008 to 2013 (Fig.…”

Analysis of the Results from the Patch Test to Para-Phenylenediamine in the TRUE Test in Patients with a Hair Dye Contact Allergy

“…Standard manufacturing practices for quasi-drugs established by the Korea Food and Drug Administration state that the permissible level of PPD is 3%; consequently, most hair dyes on the Korean market contain PPD at a level of ≤3%. Patients with ACD caused by toluene-2, 5-diamine or aminophenol, which can cross-react with PPD, have been reported, but the most effective marker of HDCA is PPD 5 , 6 , 7 . Additional studies on other agents that cause HDCA may be required in the future.…”

Occupational health hazards of female hairdressers in Jacarepaguá, Rio de Janeiro, Brazil

“…Through history and across cultures, women as well as men have felt the requisite to change the natural colour of their skin, lips and hair, or to re-establish the colour of greying hair [1]. For thousands of years, cosmetic dyes have been a part of all human cultures [2].…”

“…Significant increased risks for hairdressers have become evident due to health problems related to this group [1,7,14]. This way, there is a need for an occupation specific examination of health concerns for hairdressers.…”