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Contact allergy to citral and its constituents geranial and neral, coupled with reactions to the prehapten and prohapten geraniol
Author(s) -
Hagvall Lina,
Bruze Magnus,
Engfeldt Malin,
Isaksson Marléne,
Lindberg Magnus,
Ryberg Kristina,
Stenberg Berndt,
Svedman Cecilia,
Karlberg AnnTherese,
Bråred Christensson Johanna
Publication year - 2020
Publication title -
contact dermatitis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.524
H-Index - 96
eISSN - 1600-0536
pISSN - 0105-1873
DOI - 10.1111/cod.13404
Subject(s) - geraniol , citral , chemistry , allergic contact dermatitis , contact allergy , contact dermatitis , allergy , organic chemistry , food science , medicine , essential oil , immunology
Abstract Background Citral is commonly used as a fragrance and flavor material and consists of the aldehydes geranial and neral. Citral is included in fragrance mix (FM) II. Geranial and neral have also been identified in autoxidation of geraniol, a fragrance compound present in FM I. Objectives To study contact allergy to citral, geranial, and neral, and concomitant reactivity to oxidized geraniol and fragrance markers of the baseline series. Methods A total of 1476 dermatitis patients with suspected allergic contact dermatitis were patch tested using geranial, neral, and citral, all 3.5% petrolatum (pet.) as well as geraniol 6.0% and oxidized geraniol 11% pet. in addition to the Swedish baseline series. Results Frequencies of positive reactions to citral, geranial, and neral were 2.9%, 3.4% and 1.9%, respectively. Together, citral and geranial gave 4.2% positive patch test reactions in consecutive dermatitis patients. In patients with positive reactions to citral or its components, 25% to 34% reacted to FM II and 61% reacted to oxidized geraniol. Conclusions Patch testing with citral, its components, or oxidized geraniol detects contact allergic reactions not detected using the baseline series. Patch testing with pure geraniol was shown to be of little value. Geranial and neral, although closely chemically related, are concluded to be separate haptens.