pustule

nouns

a small inflamed elevation of skin containing pus; a blister filled with pus
pustule
is derived from
pustulate
is a type of (narrower)
(pathology) an elevation of the skin filled with serous fluid
bleb, blister, bulla
is a type of (narrower)
a small inflamed elevation of the skin; a pustule or papule; common symptom in acne
hickey, pimple, zit