A role for leukotriene antagonists in atopic dermatitis?

Atopic dermatitis is a chronic, relapsing skin condition that affects over 2% of the population. The pathophysiology of this disease is not completely understood, but immunologic abnormalities and the subsequent release of inflammatory mediators play a central role. Treatment with glucocorticoids has long been the standard of care, but their use is limited by their adverse effect profile. Leukotrienes (LTB4, LTC4, LTD4, and LTE4) are metabolites of arachidonic acid produced through the 5-lipoxygenase pathway. They play an important role in inflammatory and atopic conditions. LT modulating agents have been used with success in asthma. Recently, there has been increased interest in the potential utility of LT antagonists in atopic dermatitis. In vitro and in vivo data have demonstrated that LTs may play a key role in atopic dermatitis. The 2 different types of LT-modulating agents are 5-lipoxygenase inhibitors and LT receptor antagonists. Since the 5-lipoxygenase inhibitor acts at an earlier step in the LT synthetic pathway, it has the ability to alter the production of all the LTs, including LTB4, while the receptor antagonists target only the cysteinyl LTs, LTC4, LTD4, and LTE4. This reduction of LTB4 activity may point to a therapeutic advantage in using LT synthesis inhibitors as opposed to LT receptor antagonists for atopic dermatitis. Clinical evidence of the use of LT agents in atopic dermatitis is limited, but initial results have been promising and these agents may one day serve as corticosteroid-sparing treatments for atopic dermatitis.