The hyperpigmentation that remains after the scabs fall off usually takes 3-6 months to fade away. Crust healing is seen in a variety of skin tissue injuries, such as burns, scalds, and abrasions. Scabbing protects the local wound, reduces pain and protects the granulation tissue to prevent infection of the wound. The scab is usually formed about 10 days after the wound heals and the scab falls off. After the scabs fall off, red marks appear and hyperpigmentation occurs, darkening the new skin. Further recovery of skin tissues and pigmentation takes 3-6 months to gradually subside. The use of topical medications for scar removal can reduce local scars and accelerate the subside of pigmentation. In addition, after scab formation, if there is no local redness, swelling and pain, and fluctuating sensation under the scab, patients should pay attention to protect the scab. Try not to get rid of the scab to avoid deepening the trauma and forming more obvious scars.