blister (n.)

c. 1300, "thin vesicle on the skin containing watery matter," perhaps via Old French blestre "blister, lump, bump," from a Scandinavian source (compare Old Norse blastr "a blowing," dative blæstri "swelling"), or from Middle Dutch blyster "swelling;" all perhaps from PIE *bhlei- "to blow, swell," extension of root *bhel- (2) "to blow, swell."

late 15c., "to become covered in blisters;," 1540s, "to raise blisters on," from blister (n.). Related: Blistered; blistering.