Inflammatory mediators in normal, sensitive and diseased skin types.

The role of inflammatory mediators in the pathogenesis and pathophysiology of skin diseases is now widely accepted. We analysed the profiles of inflammatory mediators in normal, sensitive (past history of eczema, but currently patch test negative) and diseased (psoriasis and eczema) skin types to identify the patterns associated with various degrees of inflammatory dermatoses. Compared with normal skin, prostaglandin E2 was increased approximately 3.8-fold (p<0.0002) and 4.7-fold (p<0.0001) in suction blister fluids from sensitive and diseased skin types, respectively. Leukotriene B4 and interleukin-1alpha showed no differences between normal and sensitive skin types. However, in lesional skin from psoriasis and eczema patients, leukotriene B4 was increased approximately 6.6-fold (p<0.0001), whereas interleukin-1alpha was decreased approximately 3.1-fold (p<0.001). Interleukin 6 and tumour necrosis factor-alpha could not discriminate between skin types. We conclude that only prostaglandin E2 showed a significant stepwise increase on progression from normal through sensitive and inflammatory skin diseases. Levels of leukotriene B4 and interleukin-1alpha were also indicative of disease state and may be important in the pathophysiology of these conditions.