'Irritants' increase the response to an allergen in allergic contact dermatitis

Atopic dermatitis results in intrinsic barrier and immune abnormalities: Implications for contact dermatitis

“…In one report an allergen induced a contact reaction only when combined with a clinically subirritant level of SLS. 56 In addition, when patch test sites were pretreated with SLS, the threshold elicitation concentrations of contact allergens, such as cobalt and nickel, were significantly decreased. 57,58 Associations have also been observed between skin irritancy and allergic patch test reactions to nickel and colophony.…”

An epidermal equivalent assay for identification and ranking potency of contact sensitizers

“…Reconstructed epidermal models (EE) using primary human keratinocytes are currently used to test whether a chemical has irritant/corrosive properties or not (Fentem et al, 1998;Liebsch et al, 2000;Spielmann et al, 2007). The initial protocol for the potency classification was based on the clinical observation that there is a clear role of irritancy in contact sensitization due to the irritant property of many allergens (Agner et al, 2002;Basketter et al, 2007;Bonneville et al, 2007;McLelland et al, 1991). Chemicals must cause sufficient local trauma to increase cutaneous cytokine production.…”

Transfer of a two-tiered keratinocyte assay: IL-18 production by NCTC2544 to determine the skin sensitizing capacity and epidermal equivalent assay to determine sensitizer potency

“…Chemicals identified as contact sensitizers in tier 1 are subsequently tested in tier 2. This assay is based on the clinical observation that there is a clear role of irritancy in contact sensitization due to the irritant property of many allergens (Agner et al, 2002;McLelland et al, 1991;Pedersen et al, 2004). Chemicals should cause sufficient local trauma to increase cutaneous cytokine production.…”