HP40 proven safe, effective in patients with seborrheic keratoses
Use of 40% hydrogen peroxide topical solution (HP40), a proprietary, stabilized, high-concentration HP–based topical solution, safely and effectively removes seborrheic keratoses (SKs) of the face, trunk and extremities, with a low risk of inducing pigmentary changes and scarring, a recent study has shown.
Researchers randomly assigned 937 patients with four SKs each (≥1 lesion each on the face and on the trunk and/or an extremity) to HP40 or vehicle. They graded SKs at each visit using the Physician’s Lesion Assessment (PLA) scale (0, clear; 1, nearly clear; 2, ≤1 mm thick; and 3, >1 mm thick). SKs with a PLA score >0 after one treatment were retreated 3 weeks later.
There were significantly more patients treated with HP40 than with vehicle who achieved a PLA score of 0 on all four SKs (study 1: 4 percent vs 0 percent; study 2: 8 percent vs 0 percent; p<0.01 for both) and on three of four SKs (study 1: 13 percent vs 0 percent; study 2: 23 percent vs 0 percent; p<0.0001 for both) at day 106. [J Am Acad Dermatol 2018;79:869-877]
HP40 vs vehicle also resulted in a higher mean per-patient percentage of SKs that were clear (study 1: 25 percent vs 2 percent; study 2: 34 percent vs 1 percent) and clear or nearly clear (study 1: 47 percent vs 10 percent; study 2: 54 percent vs 5 percent). Furthermore, there were largely mild and resolved local skin reactions by day 106.
“HP40 provides a novel, standardized, noninvasive and elegant topical method to treat SKs that affords both patients and practitioners an alternative to the currently used destructive/ablative modalities with narrow therapeutic windows,” researchers said.
Nearly two-thirds of treated SKs in the US are remedied by cryosurgery with liquid nitrogen, but the results vary widely. Pigmentary changes normally occur, as do erythema, oedema, crusting, and blister or bulla formation. [Cryobiology 1986;23:422-432; J Am Acad Dermatol 1994;31:648-653]
“Additionally, pain during cryotherapy is significant. The reasons given by patients for avoiding SK treatment include the fear of scarring, permanent hypopigmentation, and treatment-related pain and discomfort,” researchers said. [J Clin Aesthet Dermatol 2017;10:16-25]
Although the mechanism of action of HP40 for the treatment of SK has not been fully explained, HP at different concentrations has been studied across several industries. [Ann Occup Hyg 2009;53:161-165; Am Rev Respir Dis 1988;137:1233-1235; Proceedings of Osaka Prefecture Institute of Public Health, Edition of Industrial Health 1984;22:9-13]
Analyses have shown that with penetration of HP40 into the SK lesion, the topical solution may act through direct oxidation of organic tissues, generation of reactive oxygen species and local lipid peroxidation, as well as through generation of local concentrations of oxygen that are toxic to SK cells. [EXCLI J 2017;16:426-438; Mol Med Rep 2016;13:4613-4619; Free Radic Res 2014;48:542-549; FASEB J 2014;28:485-494]
Additionally, HP40 results in less toxicity and greater melanocyte viability than with liquid nitrogen, according to recent ex vivo skin implant studies of neonatal foreskin. [J Am Acad Dermatol 2018;doi:10.1016/j.jaad.2018.03.034]