Why a patch test is never waived for a returning guest
The rule exists because it was once broken here. It is now the thing no skin treatment starts without.
A guest had been treated here before with no trouble, so the patch test was skipped to save her the second visit. Her face came up red that day. Since then nothing on skin begins without a patch test and the full product and medicine history written down on a form — not remembered, not assumed from the last appointment.