Vitamin A cream is used in different ways when used to treat different diseases. For example, when used for the treatment of acne, the correct way to use is to use it before bedtime, once a day, and the use of the area is only limited to the lesion; when used for the treatment of psoriasis and ichthyosis in the covered area, it can be applied locally on the lesion, 1-3 times a day, or as prescribed by the doctor. 1. Treatment of acne: generally choose once a day, try to choose to use before bedtime, and need to do local spot application, not suitable for large areas. 2. Treatment of psoriasis, ichthyosis: according to the location of the lesion, choose to use 1-3 times a day, specific need to follow the doctor’s instructions, after use, wash your hands in a timely manner. Adverse effects of retinoic acid cream mainly include local burning sensation, erythema and flaking, etc. Under normal circumstances, there is no need to stop taking the medicine, and when the symptoms are serious, it is necessary to take appropriate treatment under the guidance of a doctor. Vitamin A cream is contraindicated for women in the first 3 months of pregnancy, acute or subacute dermatitis, eczema and other skin diseases. To ensure the safety and efficacy of the medication, it should be used under the supervision of a doctor.