Distribution of skin-derived antileucoproteases (SKALP) in the marginal zone of the spreading psoriatic lesion.
 Two new elastase inhibitors (SKALP, skin-derived antileucoproteases) were recently described in the lesional skin in psoriasis.
 The present study investigated the distribution of SKALP activity in the marginal zone of spreading psoriatic plaques.
 In a 4-mm zone immediately adjacent to the erythemato-squamous plaques, SKALP activity was slightly increased compared to distant uninvolved skin.
 Within the lesion the anti-elastase activity was pronounced, but was significantly higher in the central zone of the plaque compared to the periphery.
 The appearance of SKALP in the psoriatic lesion appears to be a late event compared to endothelial involvement, intraepidermal accumulation of PMNs, epidermal proliferation and abnormal keratinization.
 This observation lends further support for the hypothesis that the induction of anti-elastase activity is associated with the off-switch of cutaneous inflammation.
