Vitamine D analogue-based therapies for psoriasis.

Topical vitamin D3 analogues are a mainstay of treatment in mild to moderate plaque psoriasis. Vitamin D3 analogues exert their effect in psoriasis via binding nuclear vitamin D3 receptors on genes involved in cellular proliferation, differentiation and inflammation. Currently available synthetic vitamin D3 analogues include calcipotriol, maxacalcitol, tacalcitol and calcitriol. These agents are only minimally systemically absorbed and therefore have few systemic side effects. Local irritation is the most frequently noted side effect and can be managed by combining vitamin D3 analogues with other topical or systemic therapies, such as topical corticosteroids or narrow-band UVB phototherapy. The use of a vitamin D agent helps improve the efficacy of topical corticosteroids for psoriasis and helps minimize the potential for adverse events associated with topical corticosteroid treatment. Care should be taken when combining with other topical therapies due to potential inactivation of either agent. Topical vitamin D3 analogues can be a cost-effective addition to a psoriasis treatment regimen, especially when compliance is encouraged by the tolerability of these agents and more costly systemic agents are avoided.