The first thing you need to do is to distinguish whether the bumps are above or below the surface of the skin. If it is above the surface of the skin, it may be caused by localized wart-like growths after infection with the human papilloma virus, which may appear as dry or rough warts protruding from the surface of the skin. Alternatively, it may be a soft fibrous tumor, also known as a dermatome, which is a growth of the skin itself and poses no particular health risk. If it occurs below the skin tissue, it may be a subcutaneous nodule or subcutaneous cyst, or it may be due to inflammation followed by a mechanized reaction, or it may be lymphadenitis or lymph node enlargement.