Modulation of epidermal cell division and growth by oxygenation products of arachidonic acid.

Recently accumulated data have shown that arachidonic acid derivatives play a role not only in cutaneous inflammation, but also in regulation of epidermal growth. Today, the best evidence for the involvement of leukotrienes in human skin disease is psoriasis. Such evidence includes: the presence of leukotrienes B4, C4, and D4 and monohydroxy-eicosatetraenoic acids in psoriatic skin lesions; the presence of these compounds in amounts capable of mediating epidermal proliferation, neutrophil accumulation, and vasodilatation characteristic of psoriasis; and improvement of psoriasis by 5-lipoxygenase inhibitors.