Autoxidized citronellol: Free radicals as potential sparkles to ignite the fragrance induced skin sensitizing pathway.

Citronellol, one of the most used fragrance compounds worldwide, is one ingredient of Fragrance Mix II used to assess skin allergy to fragrances in dermatitis patients. Pure citronellol is non-allergenic. Main issue is it autoxidizes when exposed to air becoming then allergenic.

Blastomycosis-like pyoderma in an immunocompetent patient.

Blastomycosis-like pyoderma is a rare skin disorder most commonly caused by bacterial infection. It is usually diagnosed in immunocompromised patients. We report a case of BLP in an immunocompetent woman, who presented with a 6-week history of verrucous cutaneous plaque of the left wrist.

Formation of methyl radicals derived from cumene hydroperoxide in reconstructed human epidermis: an EPR spin trapping confirmation by using C-substitution.

Dermal exposure to cumene hydroperoxide (CumOOH) during manufacturing processes is a toxicological issue for the industry. Its genotoxicity, mutagenic action, ability to promote skin tumour, capacity to induce epidermal hyperplasia, and aptitude to induce allergic and irritant skin contact dermatitis are well known. These toxic effects appear to be mediated through the activation to free radical species such as hydroxyl, alkoxyl, and alkyl radicals characterised basically by electron paramagnetic resonance (EPR) and spin-trapping (ST) techniques.

Understanding the skin sensitization capacity of ascaridole: a combined study of chemical reactivity and activation of the innate immune system (dendritic cells) in the epidermal environment.

To improve the prediction of the possible allergenicity of chemicals in contact with the skin, investigations of upstream events are required to better understand the molecular mechanisms involved in the initiation of allergic reactions. Ascaridole, one of the compounds responsible for skin sensitization to aged tea tree oil, degrades into intermediates that evolve via different mechanisms involving radical species. We aimed at broadening the knowledge about the contribution of radical intermediates derived from ascaridole to the skin sensitization process by assessing the reactivity profile towards amino acids, identifying whether free radicals are formed in a reconstructed human epidermis (RHE) model and their biological properties to activate the immune system, namely dendritic cells in their natural context of human HaCaT keratinocytes and RHE.

Sensitization potential and potency of terpene hydroperoxides in the cocultured activation test method.

Background: Positive patch test reactions to mixtures of oxidized terpenes containing allergenic hydroperoxides are frequently reported. However, human sensitization data for these hydroperoxides are not available.

Objectives: To analyse and evaluate the human sensitization potential and potency of hydroperoxides in vitro by using human cells.