TT #135 · Parshas Tazria · Aliyah 2 · Passuk 13
English: When the priest sees that the eruption has covered the whole body, he shall pronounce the affected person clean; when it has all turned white, that person is clean.
Chabad.org — Chumash, English translation + Rashi for Vayikra 13:13
Torah Temimah cites Sifra (Toras Kohanim) for the status of a person whose eruption spreads from a previously pure state.
Sifra — Vayikra 13, Midrash Sefer
English: “He is clean”—the verse declares the described case pure. But if an eruption spreads from a person who was already pure, that person is not thereby declared pure; the Sifra states that the status is impure.
Textual derivation
A person whose eruption spreads from a clean state is not declared clean; the resulting status is impure.