Late 16th century; earliest use found in John Banister (1532/3–?1610), surgeon. From classical Latin phlyctaena kind of pustule (Celsus) from ancient Greek ϕλύκταινα blister, pustule (Hippocrates) from an extended form (also seen in Byzantine Greek ϕλύζειν to boil over, bubble up) of the stem of ϕλύειν to boil over, bubble up + -ταινα, suffix forming nouns.