Sonoma Pharmaceuticals Inc. shares SNOA, +0.28% surged 30% in premarket trade Thursday, after the company said the U.S. Food and Drug Administration has approved its antimicrobial post-therapy gel. The gel is aimed at treating pain and itch caused by laser therapy procedures, post-microdermabrasion therapy and chemical peels. It can also be used to treat minor skin irritations and burns. In 2013, dermatology surgeons performed more than 9.5 million treatments, up almost 22% from the previous year, said Sonoma, citing the Clinical, Cosmetic and Investigational Dermatology Journal. Shares have fallen about 48% in the last 12 months, while the S&P 500 SPX, +1.16% has gained 12%.