Plugs of keratin and sebum in hair follicles (blackheads/whiteheads), which are the hallmark of acne, not firm dermal papules.
Small, white, firm, superficial keratin cysts that are rounder and more pearly-white than the typically flatter, skin-colored syringomas.
Viral papules that are distinguished by their classic central umbilication, a feature not seen in syringomas.
