Assessing the effectiveness of topical betamethasone to treat chronic chilblains: a randomised clinical trial in primary care

BACKGROUND: GPs prescribe topical corticosteroids to patients with chronic chilblains despite poor evidence for their effectiveness. The authors of the current study therefore decided to assess the effectiveness of topical steroids in a primary care setting. AIM: To assess the effectiveness of topical application of betamethasone valerate 0.1% cream in patients with chronic chilblains. DESIGN AND SETTING: A placebo-controlled, double-blind, crossover, randomised clinical trial in a Dutch primary care setting. METHOD: The study population consisted of 34 participants suffering from chronic chilblains. Intervention was topical application of betamethasone valerate 0.1% cream twice a day for 6 weeks compared with placebo. Primary outcome was the visual analogue scale on complaints (VOC). Secondary outcome was the visual analogue scale on disability (VOD). Both were assessed with a diary of daily scores on a 100 mm visual analogue scale. The authors took ambient temperatures into account, checked for a carry-over effect, performed additional analysis, and monitored adverse effects. RESULTS: On the primary outcome mean VOC, there was a difference of 0.56 mm (95% confidence interval [CI] = -2.88 to 3.99 mm) in favour of placebo (P = 0.744). On the secondary outcome mean VOD, there was a difference of 0.88 mm (95% CI = -2.22 to 3.98 mm) in favour of placebo (P = 0.567). This study found no carry-over effect and no adverse effects. CONCLUSION: In this study, topical betamethasone was not superior to placebo in the treatment of chronic chilblains. Topical betamethasone should not be used for chronic chilblains without new evidence