Twenty-eight-day follow-up of patch test reactions to p-phenylenediamine and p-phenylenediamine dihydrochloride: A multicentre study on behalf of the European Environmental and Contact Dermatitis Research Group.

BACKGROUND: There is an ongoing discussion on whether routinely patch testing with p-phenylenediamine (PPD) 1.0% pet. is safe, owing to the risk of patch test sensitization. Late-appearing patch test reactions may reflect patch test sensitization, but may also be attributable to a low degree of pre-existing sensitization. OBJECTIVES: To follow the positive patch test reactions to PPD and its salt PPD dihydrochloride (PPD-DHC) in order to characterize reaction patterns concerning time and dose in PPD-sensitized individuals. METHODS: Volunteers with previous reactions to PPD 1.0% were included and patch tested with PPD and PPD-DHC in equimolar dilution series. There were then seven follow-up visits over a period of 28 days. RESULTS: Twenty-six volunteers completed the study, of whom 23 of 26 (88%) reacted to PPD 1.0%, and 69% reacted to PPD 0.32%. Altogether, 42% and 27% reacted to the corresponding equimolar concentrations of PPD-DHC. After day 7, no new reactions were observed to any concentration tested, either of PPD or of PPD-DHC. CONCLUSION: No late-appearing reactions to PPD or PPD-DHC were observed at any dose. There is a risk of missing contact allergy when the dose is decreased.

Evaluation of concordance between labelling and content of 52 hair dye products: overview of the market of oxidative hair dye.

Hair dyes contain strong allergens and are widely available. Correct labelling is a necessity in order to provide information about the contents. To compare the labelling and content of hair dyes. In total, 52 hair dyes, from 11 different countries, were bought over the counter. High-pressure liquid chromatography was used for the analysis of p-phenylenediamine (PPD), toluene-2,5-diamine (2,5-TDA), and three oxidation products of PPD. There was good agreement between labelling and content, although seven of the 52 products (13.5%) studied were incorrectly labelled. There were differences in the geographical use of PPD and 2,5-TDA; 2,5-TDA was more common in European products, while PPD was more common in products purchased outside Europe and was present in higher concentrations. All dyes purchased in Europe contained PPD and 2,5-TDA at levels within the limits defined by European legislation, however, levels were higher in some products purchased outside Europe. Only a small group of hair dyes sold in Europe were mislabelled. Further improvement in labelling, by providing the concentration of chemicals, may facilitate products to be purchased both locally and within the global market, when travelling or on the internet.

Two sensitizing oxidation products of p-phenylenediamine patch tested in patients allergic to p-phenylenediamine.

BACKGROUND: The results from a previous study indicated the presence of several possible sensitizers formed during oxidation of the potent sensitizer p-phenylenediamine (PPD) to which PPD-sensitized patients might react, in various patterns. OBJECTIVES: To extract and analyse a yellow spot from a thin-layer chromatogram with oxidized PPD, to which 6 of 14 (43%) PPD-positive patients had reacted in a previous study, in order to identify potential sensitizer(s) and to patch test this/these substance(s) in the 14 PPD-positive patients. METHODS: The yellow spot was extracted from a thin-layer chromatogram of oxidized PPD, and two substances, suspected to be allergens, were identified by analysis with gas chromatography mass spectrometry (GCMS). The 14 PPD-positive patients, who had been previously tested with the thin-layer chromatogram of oxidized PPD, participated in the investigation, and were tested with dilutions of the two substances. RESULTS: GCMS analysis identified 4-nitroaniline and 4,4'-azodianiline in the yellow spot. Of the 14 PPD-positive test patients, 5 (36%) reacted to 4-nitroaniline and 9 (64%) reacted to 4,4'-azodianiline. CONCLUSION: The results show that 4-nitroaniline and 4,4'-azodianiline, formed during oxidation of PPD, are potent sensitizers. PPD-sensitized patients react to a high extent to concentrations equimolar to PPD of 4-nitroaniline and 4,4'-azodianiline.

Are gloves sufficiently protective when hairdressers are exposed to permanent hair dyes? An in vivo study.

BACKGROUND: The use of permanent hair dyes exposes hairdressers to contact allergens such as p-phenylenediamine (PPD), and the preventive measures are insufficient. OBJECTIVES: To perform an in vivo test to study the protective effect of gloves commonly used by hairdressers. PATIENTS/MATERIALS/METHODS: Six gloves from Sweden, Italy and Germany were studied: two vinyl, one natural rubber latex, two nitrile, and one polyethylene. The hair dye used for the provocation was a dark shade permanent dye containing PPD. The dye was mixed with hydrogen peroxide, and 8 PPD-sensitized volunteers were tested with the gloves as a membrane between the hair dye and the skin in a cylindrical open chamber system. Three exposure times (15, 30 and 60 min) were used. RESULTS: Eczematous reactions were found when natural rubber latex, polyethylene and vinyl gloves were tested with the dye. The nitrile gloves gave good protection, even after 60 min of exposure to the hair dye. CONCLUSIONS: Many protective gloves used by hairdressers are unsuitable for protection against the risk of elicitation of allergic contact dermatitis caused by PPD.

Neutrophilic and eosinophilic dermatitis caused by contact allergic reaction to paraphenylenediamine in hair dye.

BACKGROUND: Paraphenylenediamine (PPD) in hair dyes can cause systemic as well as cutaneous allergic reactions such as neutrophilic and eosinophilic dermatitis. The symptoms are often severe. The acute lesion is normally histologically indistinguishable from any eczematous reaction with marked spongiosis. OBSERVATIONS: We report a case of allergic contact dermatitis caused by the use of hair dye containing PPD that developed in a patient who had been using the same hair dye for many years. Her symptoms included scalp dermatitis and widespread skin lesions as well as lymphadenopathy and quite possibly dyspnea resembling asthma. What is most remarkable about this case is the histopathologic finding of neutrophilic cellulitis and a marked neutrophilic infiltrate with variable spongiosis. This unique finding was confirmed by histologic analysis of a patch test lesion specimen. CONCLUSION: It is always important to consider contact allergic dermatitis as a cause of dermatitis because of the variable presentation of the disease, including unique histologic findings that do not fit the conventional picture, as in the present case.