Chest can be rubbed tincture of azelaic acid hydrochloride, but breastfeeding women are prohibited to use. Tincture of azelaic acid hydrochloride is the main ingredient of azelaic acid, which can prevent the replication of DNA causing cell damage and necrosis, clinically commonly used in the treatment of vitiligo, it can promote the darkening of the skin at the white spots, so that the epidermal melanocyte proliferation, pigmentation, thus treating vitiligo, the effect is remarkable, if the use of the process of physical discomfort, you should stop using it immediately. For azelaic acid hydrochloride tincture allergy, pregnant and lactating women are prohibited to use, azelaic acid hydrochloride tincture can enter the body through the chest, azelaic acid hydrochloride tincture in the ingredients will have an impact on the fetus, resulting in genetic mutation or fetal deformity, so the female breastfeeding chest is not recommended to use. If it is necessary to carry out the rubbing of tincture of azelaic acid hydrochloride, it should be used under the formal guidance of a doctor, and should not be used on its own, so as not to cause harm to the body.