Niacinamide, Prebiotic, and Postbiotic Emollient Versus Urea 10% Cream for EGFR Inhibitor-Induced Xerosis and Pruritus: A Double-Blind Randomized Trial

Background: Xerosis and pruritus are frequent and burdensome adverse effects of epidermal growth factor receptor inhibitors (EGFRIs), reflecting a therapy-induced disruption of epidermal barrier integrity and keratinocyte homeostasis. While urea-based emollients are widely recommended, emerging dermocosmetic strategies targeting barrier repair and microbiome modulation may offer alternative or complementary benefits. Objective: To compare the efficacy and tolerability of a niacinamide-, prebiotic-, and postbiotic-enriched emollient with a standard 10% urea cream in the management of EGFRI-induced xerosis and pruritus. Methods: In this prospective, randomized, double-blind, parallel-group trial, 44 patients receiving EGFR inhibitors and presenting with clinically significant xerosis and pruritus were assigned to receive either a 10% urea cream or a formulation containing 4% niacinamide, α-glucan oligosaccharide, and Lactobacillus ferment lysate. Treatments were applied twice daily for 12 weeks. Outcomes included reflectance confocal microscopy (RCM) assessment of epidermal microstructure, pruritus intensity measured by visual analog scale (VAS), and quality of life evaluated by Dermatology Life Quality Index (DLQI) and Skindex-16. Results: Both treatments induced significant improvements across all endpoints. RCM demonstrated restoration of stratum corneum organization and epidermal architecture in both groups, with no significant between-group differences. Pruritus decreased markedly, with VAS scores declining from approximately 6.5 at baseline to 2.36 in the niacinamide-based group and 2.48 in the urea group at week 12. Quality-of-life measures improved substantially, with DLQI reductions of 66% and 61% in the niacinamide and urea groups, respectively. Skindex-16 scores showed comparable improvements. No statistically significant differences were observed between treatments for any outcome measure. Both formulations were well tolerated, with no relevant adverse events. Conclusions: A niacinamide-, prebiotic-, and postbiotic-containing emollient demonstrated efficacy comparable to that of a standard 10% urea cream in improving EGFRI-induced xerosis and pruritus over 12 weeks. These findings support the formulation as a viable option for supportive oncodermatologic care, while proposed effects on epidermal barrier pathways, inflammation, and microbiota-host interactions remain biologically plausible mechanisms that were not directly assessed in this trial.