A blackhead is also called an open comedo (single for comedone), and it is a clogged pore in the skin that is open to the air. Keratin (skin protein) and sebum …
A Pilar Cyst, aka a trichilemmal cyst, an isthmus-catagen cyst, or a “wen”, looks identical on examination to the more common epidermoid cyst, except that 90% …