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Unexpected positive patch test reactions to sesquiterpene lactones in patients sensitized to the glucose sensor

Anne Herman¹, Martin Mowitz², Olivier Aerts³

¹Department of Dermatology, Cliniques universitaires Saint-Luc, Brussels, and IREC (Institut de Recherche Experimentale et Clinique) Pôle Pneumologie, ORL, Dermatologie, Université Catholique de Louvain, Brussels, Belgium.

Contact Dermatitis

|June 6, 2019

Abstract

Background:

Most diabetic patients sensitized to FreeStyle Libre react to isobornyl acrylate (IBOA), with a considerable number of them also showing unexpected positive patch test reactions to sesquiterpene lactone (SL) mix (SLM) tested in the baseline series.

Objectives:

To compile patch test results of subjects affected, and provide potential explanations for this association.

Patients And Methods:

Fifty-three Freestyle Libre-allergic patients were patch tested with IBOA and/or SLM, and several were also patch tested with the components of SLM. Chromatographic analyses were performed on the glucose sensor, IBOA, and the components of SLM.

Results:

Thirty-three patients reacted positively to the components of SLM, and 11 of 27 patients reacted positively to alantolactone, in particular. Gas chromatography-mass spectrometry (GC-MS) analyses did not detect these chemicals in the different parts of the glucose sensor, or in IBOA.

Conclusion:

Significant co-sensitizations between SLs on the one hand and the glucose sensor FreeStyle Libre and/or isobornyl acrylate on the other hand exist, without evidence of the presence of SLs via GC-MS analysis. Cross-reactions between them seem improbable. As a possible hypothesis, a common precursor for both, such as camphene, may exist.

Keywords:

FreeStyle Libre GC-MS allergic contact dermatitis chemical analysis diabetes mellitus glucose sensor isobornyl acrylate medical device sesquiterpene lactones simultaneous reactions

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