I N T R O D U C T I O N
Hypochlorous acid is reported to have anti-itch and anti-inflamma- tory potential in human patients suffering from atopic dermatitis (AD).1 However, the possible mechanism of action has not been well characterized. Empirically, the antiseptic potential of hypochlorous acid can be the predominant mechanism1 as colonization with Sta- phylococcus aureus (S. aureus) is an important trigger factor for AD.2 However, it is likely that hypochlorous acid has effects beyond antiseptic properties, particularly as a rapid onset of itch reduction is reported.1 Sodium hypochlorite, an alkaline aqueous solution of HOCl, has been described to interact with the pro-inflammatory transcription factor NFjB,3 leading to in vivo efficacy in a mouse model of irradiation dermatitis. Thus, it could be hypothesized for hypochlorous acid that some modulating effects beyond antiseptic properties might be responsible for the clinical efficacy seen in patients with AD. This study was performed to determine an anti-inflammatory and anti-itch mechanism of a 0.05% hypochlorous acid hydrogel in a chronic allergen-induced mouse model, which resembles several characteristics of atopic dermatitis.4-6 In addition to gain information about possible immune-modulating properties and direct effect on neurons, the effect of hypochlorous acid was tested in vitro on keratinocytes, dendritic cells, and dorsal root ganglia (DRG) neurons.
