Friday, May 21, 2010

Linalool--a significant contact sensitizer after air exposure. (terpene in perfume)

[Comment:  Linalool is a terpene used in perfumes.]
 
Linalool--a significant contact sensitizer after air exposure.
Christensson JB, Matura M, Gruvberger B, Bruze M, Karlberg AT.
Contact Dermatitis. 2010 Jan;62(1):32-41.

Department of Dermatology, Sahlgrenska University Hospital, Gothenburg, Sweden. johanna.brared-christensson@vgregion.se
Abstract
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.

PMID: 20136877 [PubMed - indexed for MEDLINE]
 

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