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.
PPD
active sensitization
allergic contact dermatitis
contact allergy
delayed
dilution series
false-negative reactions
hypersensitivity
late-appearing patch test reactions
Journal
Contact dermatitis
ISSN: 1600-0536
Titre abrégé: Contact Dermatitis
Pays: England
ID NLM: 7604950
Informations de publication
Date de publication:
Jul 2019
Jul 2019
Historique:
received:
11
11
2018
revised:
20
01
2019
accepted:
23
01
2019
pubmed:
27
1
2019
medline:
24
12
2019
entrez:
27
1
2019
Statut:
ppublish
Résumé
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. 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. 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. 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. 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.
Sections du résumé
BACKGROUND
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
OBJECTIVE
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
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
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
CONCLUSIONS
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.
Substances chimiques
Coloring Agents
0
Phenylenediamines
0
4-phenylenediamine
U770QIT64J
Types de publication
Journal Article
Multicenter Study
Langues
eng
Sous-ensembles de citation
IM
Pagination
1-8Informations de copyright
© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.