A black bump on the chest can be a keloid, mole, birth mark, wart, abscess
or some allergic eruption.
Keloids occur in skin after
surgical incisions, traumatic wounds, vaccination sites, burn injuries. Keloids often run in families. They most often on the chest, back, shoulders, and earlobes. Keloids are firm, rubbery lesions or shiny, fibrous nodules, and can vary from pink to flesh-colored or red to dark brown in color and usually turn unsightly.