Azelaic acid tincture can be used to treat vitiligo. Tincture of azelaic acid hydrochloride is one of the most commonly used medications for vitiligo, and is effective in treating halo nevus, progressive vitiligo, and stable vitiligo. Tincture of azelaic acid is usually used only as an adjunctive drug, and can be used together with halometasone cream, tacrolimus ointment and other drugs at the same time. Tincture of azelaic acid has a certain degree of skin irritation, may cause redness, swelling, itching or pain in the skin where the drug is used, usually not recommended to use the whole body on a large area. Some patients may experience localized redness and darkening of the skin when using the drug, but it can usually recover on its own. Due to the strong irritation of tincture of azelaic acid hydrochloride, it is necessary to consult a doctor first and use the medicine under the doctor’s supervision. The use of tincture of azelaic acid hydrochloride is usually not recommended for children, breastfeeding and pregnant women.