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A general population from Thailand: incidence of common allergens with emphasis on para‐phenylenediamine
Author(s) -
White J. M. L.,
Gilmour N. J.,
Jeffries D.,
Duangdeeden I.,
Kullavanijaya P.,
Basketter D. A.,
McFadden J. P.
Publication year - 2007
Publication title -
clinical and experimental allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 154
eISSN - 1365-2222
pISSN - 0954-7894
DOI - 10.1111/j.1365-2222.2007.02846.x
Subject(s) - hair dyes , medicine , incidence (geometry) , p phenylenediamine , allergy , population , dermatology , sensitization , patch test , pediatrics , immunology , environmental health , composite material , chemistry , physics , materials science , organic chemistry , dyeing , optics
Summary Background Most studies on the prevalence of allergy to the permanent hair dye chemical para‐phenylenediamine (PPD) are reported from populations of eczema patients attending patch‐test clinics, and are assumed to be much higher than in the normal population. No data exist on incidence of senitization to PPD resulting from the use of commercial hair dye preparations over a defined time period. Method A total of 2545 healthy adult volunteers (Bangkok) were screened for PPD allergy through standard patch testing. Volunteers not allergic to PPD were then recruited into two groups: one group applying a commercial hair dye brand as instructed on a monthly basis for 6 months ( n =548) and the other group (controls) ( n =516) was instructed not to dye their hair for 6 months. Sensitization to PPD resulting from the use of hair dye over this period was then detected by repeat patch testing. Results The prevalence of PPD allergy in a normal adult population was 2.7% ( m =2.4%, f =3.2%). Projected to the adult Thai population, at least 1 000 000 Thai individuals could be allergic to PPD. The incidence of sensitization through the monthly application of standard commercial hair dye preparations over a 6‐month period was 1.3%, substantially higher than in controls (0.4%), although numbers were small and not statistically significant. Interpretation There is a higher prevalence of hair dye allergy among the normal population than previously thought. The incidence of new cases of PPD allergy would indicate that current regulations and practice of hair dye exposure lead to PPD sensitization and allergy, which is a public health problem.