Hypertrophic scars
These scars are more common in the young, following burns and in people with darker skin. These scars are usually red, thick and elevated and can be itchy or painful, but their growth is confined within the boundaries of the original wound. Hypertrophic scars usually start to develop within weeks after the injury and may improve naturally, although this process can take up to a year or more.
Keloid scars
Keloids may occur at any age, but tend to develop more readily in younger individuals and in darker-skinned people. These are thick, rounded, irregular clusters of scar tissue that extend beyond the original wound. They often appear red or darker in colour compared with the surrounding skin. Keloids may not develop for many months after injury, and may also worsen during pregnancy.
Atrophic scars
These scars are generally small, round depressions that lie below the surface of the surrounding skin. They are formed when the healing process is disrupted and insufficient new connective fibres are formed following acne or chickenpox.