A novel treatment of contact dermatitis by topical application of phospholipase A₂ inhibitor: A double-blind placebo-controlled pilot study

Phospholipase A₂ hydrolyzes membrane phospholipids releasing arachidonic acid and lysophospholipids. These are key precursors of inflammatory mediators, such as prostaglandins, leukotrienes, thromboxanes and PAF, in numerous inflammatory/allergic diseases, including skin inflammation. Accordingly, inhibition of PLA₂ has long been postulated as a potentially potent antiinflammatory therapy. In the present study we tested the effect of a novel PLA₂ inhibitor on contact dermatitis in human subjects. A double-blind, placebo-controlled pilot study was conducted on contact dermatitis patients (n = 11) treated with the inhibitor-containing topical preparation (1% cream). Disease severity was assessed by physician's assessment before treatment (day 0) as well as after 14-days and 30-days. Patients treated with 1% PLA2 inhibitor-containing cream showed a 69.9% reduction in disease score while placebo-treated patients showed a reduction of 36.5% with p = 0.0024. The clear improvement in the disease score of inhibitor-treated patients supports the involvement of PLA₂ activity in skin inflammation and the therapeutic prospective of its inhibition.