Topical oil formulation of plant extracts and vitamins as effective treatment for stretch marks and xerosis—An observational longitudinal study

Background: Stretch marks are linear scars that result from elastic fiber destruction. They usually occur as the consequence of rapid change in the body mass (weight gain and loss, pregnancy, weightlifting), long-term steroid use, or endocrinopathies. Treatment is challenging and mainly based on topical and procedural therapies, although the standard of care is still under debate. Purpose: To evaluate the efficacy and tolerance of a topical oil formulation of plant extracts and vitamins on the aesthetic improvement of stretch marks and xerosis. Materials and methods: Fifty male and female patients, aged between 14 and 45 years, with stretch marks referring at the University Hospital Federico II, Naples, were enrolled between March and November 2019. Topical application of plant extracts and vitamin-rich oil was performed twice daily on affected skin for 4 months. Patients were monitored at baseline (T0), and at two-month (T1) and 4-month (T2) follow-ups, through clinical and dermoscopic assessment, confocal microscopy, cutaneous ultrasound, MoistureMeterEpiD, and X-Rite spectrocolorimeter. Primary endpoints were as follows: 70% clinical improvement of stretch marks and 3-point decrease in clinical score from baseline to T2. Secondary endpoints were as follows: change in the T0 parallel pattern of collagen fibers at confocal microscopy, cutaneous thickness increase at ultrasounds, cutaneous hydration increase at MoistureMeterEpiD, erythema reduction at X-Rite spectrocolorimeter, and safety and adverse events (AEs). Results: At 4-month follow-up, stretch marks improved objectively and subjectively in all patients (p < 0.001). In detail, there was a 29% and 71% improvement in clinical appearance of stretch marks at T1 and T2, respectively, as documented dermoscopically and by the 3-point reduction in the assessor's mean clinical score at each follow-up visits [from 8.1±0.7 at baseline to 5.7±1.0 at T1 and 2.3 ±0.5 at T2 (p < 0.001)]. Erythema decreased by 15% and 30% and in parallel hydration increased by 25% and 71%, at T1 and T2, respectively (p < 0.001). At T2 confocal microscopy of stretch marks, dermal collagenous fibers assumed casual disposition with reticular pattern and refractivity, as signs of collagen remodeling and neocollagenesis, and also the T2 cutaneous ultrasound revealed increased epidermal thickness and decreased dermal hypoechogenicity as for a higher skin hydration. Conclusion: Our study showed that a topical oil formulation rich in plant extracts and vitamins appears to be effective and safe in treating stretch marks and xerosis