These are hard, rock-like deposits of calcium, which feel much firmer than the keratin-filled plugs of comedones.
These are tiny, white, firm, superficial keratin cysts that cannot be easily expressed, unlike open comedones (blackheads) which can be.
These are true cysts containing an oily, yellowish fluid, and are typically softer and more numerous on the trunk and axillae than typical comedones.
These are small, flat-topped, skin-colored papules, representing benign sweat duct tumors, most commonly found around the eyes.
