First, you haven't burned any time through MS-1. It is nowhere near expected that students start doing derm research beginning from the first semester of MS-1.
I don't recommend getting involved in a basic science project in Derm because it takes forever to publish. I'm assuming he thinks he won't have a publication out on that project by the end of the summer, so he threw a review at you to complete that can be finished relatively quickly.
Have you already fully committed to the basic science project in the summer with this faculty member? Depending on how high he is up the faculty ladder (i.e. Program Director or Chairman), you might not have a choice to back out now. In general, unless you're an MD/PhD or doing a year-long prestigious research program year that is basic science oriented like the HHMI-NIH Research Scholars (Cloister) Program, there is really no point in doing lab research, because unless you actually get a publication submitted, it doesn't really help you on the interview trail. Just having it down as a "research experience" in the meantime, doesn't really help a whole lot, when it comes to outside Derm programs.
According to Charting Outcomes:
http://www.nrmp.org/wp-content/uploads/2014/09/Charting-Outcomes-2014-Final.pdf, the mean number of research experiences (altogether) is 4.3 and the mean number of abstracts, presentations, and publications (all added together, not just publications) is 9.5. As
@dermie1985 mentioned, it's pretty easy to inflate the research experiences number with research experiences (w/dates) that you did research at your home program, summer after MS-1, and derm research electives.
These things come from the ERAS application under the "Experience Tab" and the "Publications Tab"
https://www.aamc.org/students/download/375002/data/worksheet2015.pdf
This is what qualifies as a "Publication" in the ERAS application:
Peer Reviewed Journal Articles/Abstracts (Published)
Peer Reviewed Journal Articles/Abstracts (Other than Published) - Statuses: Submitted, Provisional Accepted, Accepted or In-Press
Peer Reviewed Book Chapter
Scientific Monograph
Other Articles
Poster Presentation
Oral Presentation
Peer Reviewed Online Publication
Non Peer Reviewed Online Publication
As you can see even this section can be inflated since even a book chapter counts as a publication.