Can contact allergy to p‐phenylenediamine explain the high rates of terpene hydroperoxide allergy? – An epidemiological study based on consecutive patch test results

Abstract

PPD sensitization cannot explain the high rates of sensitization to Lin-OOHs and/or Lim-OOHs. Contact allergy to oxidized linalool is more strongly associated with fragrance allergy than with PPD allergy.

Contact Allergy: A Review of Current Problems from a Clinical Perspective

“…As the majority of the patients reacted to only one of the oxidation mixtures, the specificity of the reactions is supported [ 60 ]. Such specificity is also supported by the results of a database study of consecutively patch tested eczema patients ( n = 3843) from 2012 to 2015, tested concomitantly with p-phenylenediamine (PPD), Lim-OOHs and Lin-OOHs, where the association between positive reactions was not stronger than expected by chance [ 61 ]. In the period 2010 to 2015, the prevalence of sensitization to the 26 fragrances, and concomitant reactivity to FM I and/or FM II was addressed by the same authors; of 6004 patients, 940 (15.7%) were fragrance-sensitized, mostly to Lin-OOH (3.9%), Evernia furfuracea (3.0%), Lim-OOH (2.5%), and HICC (2.1%) [ 62 ].…”

Oxidation products and the skin – the effect of hydroperoxides

“…Theoretically, PPD-sensitized individuals could therefore be at increased risk of having patch test reactions to terpene hydroperoxides, owing to concomitant unspecific reactions. However, no concomitant sensitization to PPD and the terpene hydroperoxides beyond that expected by chance could be identified (19).…”

“…All clinical studies have shown that ∼40% of the patients reacting to oxidized fragrance terpenes also react to fragrance markers in the baseline series . Also, the study by Bennike et al showed a clear association between reactions to the terpene hydroperoxides and reactions to the fragrance markers in the baseline series . It should be noted that significantly more patients reacting only to oxidized limonene with no other fragrance allergies reported problems with fragranced products than those without a patch test reaction to any fragrance patch test material in the multicentre study performed by Bråred Christensson et al .…”

Contact dermato-allergology - review of the literature

“…Para-phenylenediamine (PPD), one of the strongest allergens in the Baseline series, and its possible cross-reaction with fragrances, was the subject of a retrospective study carried out on 3912 patients, published in February 2017 [5]. Although it was initially assumed that there would be a risk of cross-reactivity between PPD and terpene hydroperoxides (fragrance allergens) due to the similar chemical changes they produce on skin proteins, the study demonstrated that sensitization to PPD cannot explain the high percentage of sensitization to these substances (Lin-OOHs and/or Lim-OOHs).…”

“…Although it was initially assumed that there would be a risk of cross-reactivity between PPD and terpene hydroperoxides (fragrance allergens) due to the similar chemical changes they produce on skin proteins, the study demonstrated that sensitization to PPD cannot explain the high percentage of sensitization to these substances (Lin-OOHs and/or Lim-OOHs). Rather, it is believed to be a genetic predisposition to multiple sensitizations, and the high risk of contact allergy to Lin-OOHs in PPD-positive patients is believed to be due to an increased risk of simultaneous exposure to fragrances [5].…”