White spots on the skin after sun exposure may be florid chaff rash, post-inflammatory hypopigmentation, vitiligo and other diseases, according to the cause of the need to use itraconazole, prednisone and other drugs for treatment. 1. florid chaff rash: mainly due to Malassezia infection, mostly in the summer, the damage is mostly seen in the neck trunk and so on. It can be treated with ketoconazole, itraconazole and other drugs. 2. post-inflammatory hypopigmentation: generally with eczema, dermatitis, psoriasis and other primary medical history, usually temporary white spots, after a certain period of time can be restored on their own, pay attention to avoid scratching stimulation. 3. Vitiligo: it is an immune-related disease, which can be treated with prednisone, carbotriol, tacrolimus ointment, pimecrolimus ointment, azelaic acid hydrochloride and other medications, in addition to transplantation therapy, depigmentation therapy can also be used to treat vitiligo. There are many reasons for the appearance of white patches on the skin, so it is recommended to go to the hospital for examination and use drugs under the guidance of doctors.