317 Topical Apple Derivatives
to INCIDecoder, there are currently over 1,000 apple-based products that are actively
used and marketed to the public.7 Some common claims about the skincare benefits of
apple derivatives tout that it is “rich in AHAs” that rid the skin of “dead skin cells and
impurities.”8 Other claims boast that these products can “retexturize, resurface, and reveal
luminous skin” and these products have a host of “antioxidants.”9,10 With the projected
US $70 billion increase in the skincare market by 2026 (projected by Fortune Business
Insights), the need to understand “trendy” ingredients’ utility is more important than ever
to prevent problematic use by consumers.11
To better understand and communicate the efficacy of apple derivatives in dermatological
practice, consolidation, and thorough evaluation of existing literature are crucial. In this
paper, we are performing a systematic review of publications discussing the varied effects
of Malus organisms, in vivo, on human skin health. We address the limitations and the
positive and negative outcomes of each study to better understand the prospects of apple-
derived products in not only the consumer market, but also in maintaining the overall
health of the integumentary system.
METHODS
72 possible search terms were made by combining terms and using principles of Boolean
operators (Table I). Using these terms, a C# .NET console application searched PubMed to
query the resulting links through HTTP. All links and publications were collected in July
2022. Duplicates were removed, leaving 209 unique publications. We initially reviewed
Table 1
List of Terms Used to Systematically Search PubMed, Created Using Boolean Operators
skin* topical* “Pyrus malus” derm* topical* “Pyrus malus” cosmetic* topical* “Pyrus malus”
skin* topical* Apple derm* topical* Apple cosmetic* topical* Apple
skin* topical* “Malus
domestica”
derm* topical* “Malus
domestica”
cosmetic* topical* “Malus
domestica”
skin* topical* “Crab apple” derm* topical* “Crab apple” cosmetic* topical* “Crab apple”
skin* apply* “Pyrus malus” derm* apply* “Pyrus malus” cosmetic* apply* “Pyrus malus”
skin* apply* Apple derm* apply* Apple cosmetic* apply* Apple
skin* apply* “Malus domestica” derm* apply* “Malus domestica” cosmetic* apply* “Malus domestica”
skin* apply* “Crab apple” derm* apply* “Crab apple” cosmetic* apply* “Crab apple”
skin* application “Pyrus malus” derm* application “Pyrus malus” cosmetic* application “Pyrus malus”
skin* application Apple derm* application Apple cosmetic* application Apple
skin* application “Malus
domestica”
derm* application “Malus
domestica”
cosmetic* application “Malus
domestica”
skin* application “Crab apple” derm* application “Crab apple” cosmetic* application “Crab apple”
hair* topical* “Pyrus malus” nail* topical* “Pyrus malus” beaut* topical* “Pyrus malus”
hair* topical* Apple nail* topical* Apple beaut* topical* Apple
hair* topical* “Malus domestica” nail* topical* “Malus domestica” beaut* topical* “Malus domestica”
hair* topical* “Crab apple” nail* topical* “Crab apple” beaut* topical* “Crab apple”
hair* apply* “Pyrus malus” nail* apply* “Pyrus malus” beaut* apply* “Pyrus malus”
hair* apply* Apple nail* apply* Apple beaut* apply* Apple
hair* apply* “Malus domestica” nail* apply* “Malus domestica” beaut* apply* “Malus domestica”
hair* apply* “Crab apple” nail* apply* “Crab apple” beaut* apply* “Crab apple”
hair* application “Pyrus malus” nail* application “Pyrus malus” beaut* application “Pyrus malus”
hair* application Apple nail* application Apple beaut* application Apple
hair* application “Malus
domestica”
nail* application “Malus
domestica”
beaut* application “Malus
domestica”
hair* application “Crab apple” nail* application “Crab apple” beaut* application “Crab apple”

318 JOURNAL OF COSMETIC SCIENCE
the abstracts using inclusion and exclusion criteria and removed all irrelevant papers. Our
inclusion criteria included experiments measuring topical apple derivatives in vivo that
treated dermatological diseases, that were tested on all species, that included case studies,
and were published at any time. Exclusion criteria included experiments that did not have
a vehicle or control, trials that focused on in vitro and ex vivo results, papers that only had
histological parameters, reviews, commentaries, any publications that did not present any
original data, and articles not written in English. The resultant sum included 21 papers
that fit the exclusion and inclusion criteria given.
These publications were read in entirety for their content, which left 14 papers that fulfilled
both the inclusion and exclusion criteria (Figure 1). The papers were analyzed for certain data
points and limitations, and potential future research was assessed, discussed, and recorded.
Data categories that were not included in each study were listed as “not available” (Figure 1).
Figure 1. PRISMA Model of the performed methods, updated as of July 2022.