Efficacy and safety of oral retinoids in different psoriasis subtypes: a systematic literature review.

BACKGROUND: There is limited evidence regarding the efficacy and safety of retinoids in different psoriasis subtypes. OBJECTIVE: To systematically review the available literature on: (i) modalities of administration and prescription of oral retinoids as single agent or combined therapy for the treatment of plaque-type psoriasis (PV), nail psoriasis and localized and generalized pustular psoriasis : initial and optimal dosage; (ii) skeletal toxicity of retinoid for the treatment of psoriasis. METHODS: A systematic literature search was carried out in MEDLINE, EMBASE, and Cochrane Library databases from 1975 to 2010 searching for randomized controlled trials and observational studies evaluating 1) various dosages of retinoid in psoriasis and 2) skeletal toxicity of retinoid in psoriasis. Articles were limited to human subjects and English/French languages. RESULTS: Efficacy of retinoids in psoriasis. Among 1348 identified references, 44 published studies were included. Starting daily dosages between 10 and 25 mg and stepwise escalation were associated with higher clinical efficacy and lower incidence of adverse events in comparison with higher doses and regimens rapidly reaching optimal dose. Retinoids as single agent therapy appeared to show limited efficacy in PV, while the good clinical efficacy reported in pustular forms should be cautiously considered, given the spontaneously remitting course of the disease. Combining retinoids with phototherapy appeared to be highly effective in patients with PV. Potential skeletal toxicity of retinoids. 15 published studies out of 105 identified references were included. There is no strong evidence of an increased risk of skeletal abnormalities in psoriasis patients treated with retinoids. CONCLUSION: Acitretin appears to provide better efficacy in pustular psoriasis than in PV as a single agent treatment. There is no evidence for skeletal toxicity of retinoids in the setting of psoriasis, and accordingly monitoring this risk through X-ray is not warranted.