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Linalool – a significant contact sensitizer after air exposure
Author(s) -
Christensson Johanna Bråred,
Matura Mihály,
Gruvberger Birgitta,
Bruze Magnus,
Karlberg AnnTherese
Publication year - 2010
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/j.1600-0536.2009.01657.x
Subject(s) - linalool , patch test , contact allergy , allergen , patch testing , allergic contact dermatitis , chemistry , contact dermatitis , terpene , allergy , dermatology , food science , medicine , immunology , organic chemistry , essential oil
Background: Linalool is a widely used fragrance terpene. Pure linalool is not allergenic or a very weak allergen, but autoxidizes on air exposure and the oxidation products can cause contact allergy. Oxidized (ox.) linalool has previously been patch tested at a concentration of 2.0% in petrolatum (pet.) in 1511 patients, and 1.3% positive patch test reactions were observed. Objective: To investigate the optimal patch test concentration for detection of contact allergy to ox. linalool. Methods: Four concentrations of ox. linalool (2.0%, 4.0%, 6.0%, 11.0% pet.) were tested in 3418 consecutive dermatitis patients. Results: Ox. linalool 2.0%, 4.0%, 6.0%, and 11.0% pet. detected positive patch test reactions in 0.83%, 3.2%, 5.3%, and 7.2% of the tested patients, respectively. The doubtful reactions increased with rising concentrations but relatively less, giving 5.1%, 6.4%, and 7.3% doubtful reactions, respectively, for ox. linalool 4.0%, 6.0%, and 11.0% pet. Few irritative reactions were seen. Conclusions: Raising the patch test concentration for ox. linalool gave a better detection of contact allergy, as many as 5–7% positive patch test reactions were detected. We suggest a patch test concentration of ox. linalool 6.0% pet. for future patch testing, giving a dose per unit area of 2.4 mg/cm 2 when 20 mg test substance is tested in small Finn Chambers ® .