ΔE 22.7, loose: different enough that you should pick on purpose. Reikland Fleshshade is noticeably lighter, more saturated than Strong Skin Wash.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 23). Reikland Fleshshade is noticeably lighter, more saturated than Strong Skin Wash.
The same difference applies the other way round: Strong Skin Wash is noticeably darker, more muted.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Strong Skin Wash on the colour wheel See Reikland Fleshshade on the colour wheel
All matches: Strong Skin Wash equivalents · Reikland Fleshshade equivalents