Platelet activating factor (PAF) and lyso-PAF in inflamed human skin

The extent of PAF synthesis and its role in inflammatory skin disorders are not known. Skin exudates were collected from suction blisters or bbrasions on healthy and inflamed human skin and analysed by gc-ms. The mean PAF andlyso-PAF values for skin of healthy subjects were 1.86±0.92 (n=7) and 160±21 (n=8) nM, respectively, in suction blister exudates, and 0.38±0.08 (n=14) and 11.0±1.9 (n=13) pmol/abrasion, respectively. PAF levels were not altered in psoriasis, nickel contact dermatitis, delayed pressure urticaria, mastocytosis or immediate and late phase reactions to antigen. Significantly, lesslyso-PAF was found in uninvolved skin of psoriasis. Increasedlyso-PAF was found in nickel contact dermatitis compared with untreated skin of the same subjects or skin or normal healthy volunteers. We conclude that, if PAF is a significant mediator of inflammation in human skin, it may remain associated with the synthesising cell or act in its immediate proximity.