Effect of topical treatment with 7.5% urea in Ichthyosis Vulgaris: A randomized, controlled, double blinded, split body study evaluating the effect of urea cream compared to the vehicle (moisturizing) cream

BACKGROUND: Ichthyosis Vulgaris (IV) is a common genetic skin disease, characterized by dry, scaling skin and itch. Urea cream has been a central part of IV treatment for decades, but only few studies have evaluated the effect of urea compared to basic moisturizers. OBJECTIVE: To evaluate the treatment effect of 7.5% urea cream compared to a basic moisturizer in patients with IV. METHODS: Participants (n = 14) were randomized to apply the 7.5% urea cream on one body half and a basic moisturizer on the other during a study period of 4 weeks. Measuring points on participants arms and legs were evaluated at baseline and at endpoint with a patient questionnaire visual assessment scale (VAS), a clinical scoring, and electronic skin hydration analysis to assess the treatment effects. RESULTS: On the arms, no significant differences between the two treatments were found. On the legs, however, the urea treated areas had a significantly higher decrease in SRRC score (0.7 points [95% CI: 1.1–0.3, p < 0.005]) and increase in hydration (32.1 μS [95% CI: 10.9‐53.2, p < 0.006]). CONCLUSION: Skin hydration improved significantly with both urea and moisturising treatment. On the legs, with most keratinization, urea was superior. Trial registry: https://clinicaltrials.gov/ct2/show/NCT02978209?cond=Ichthyosis+Vulgaris&draw=1&rank=2.