Herpes zoster is usually cured in 5-7 days after crusting, but the recovery of residual neuralgia varies depending on the degree of immunity of the body. For young people with high immunity, the residual neuralgia is basically cured at the same time. However, in the case of elderly people and children with low immunity, or in the case of patients with medical diseases with low immunity, such as tumors or hypertension, diabetes, or coronary heart disease, the posterior neuralgia will remain for some time. If the herpes zoster scabs do not come off easily, you can apply topical zinc oxide ointment of boric acid, about the thickness of a dollar coin, keep it for about an hour, and gently swab it off with a cotton swab to wipe off the unsprung scabs.