These are the most stubborn and frustrating forms of acne to remove by far. They root themselves deep into pores, effectively burrowing into the skin and deepening over time. The head may shrink, but the body hidden beneath the surface may be very active. This can lead to extreme self-confidence and comfort issues. In many cases, blackhead outbreaks can be a real challenge to eradicate due to their burrowing nature, absorbing oils and debris.