The Power of Combination Topical Therapy for Psoriasis.

Psoriasis is a chronic inflammatory skin disease where the use of topical corticosteroids is a mainstream treatment. However, the continuous use of high potency topical corticosteroids is limited by a variety of well known adverse events which include, atrophy, and telangiectasia. Also, inhibition of lipid synthesis by steroids can cause impairment of the epidermal barrier, which is already disrupted in most of the inflammatory cutaneous disorders such as psoriasis. This will further lead to increase transepidermal water loss (TEWL), decreased hydration, dry skin, and irritation. On the other hand, topical vitamin D analogs directly affect keratinocyte proliferation and differentiation as well as modulation of epidermal lipids and antimicrobial peptides. Although the exact mechanism of action of topical vitamin D analogs is not well understood in the treatment of psoriasis, their efficacy and safety has been shown in several clinical trials over the years and they are widely used for psoriasis. Therefore, combination of topical steroids and vitamin D analogs may be a logical option for the treatment of psoriasis.