The light brown spots on children’s arms may be caused by post-inflammatory hyperpigmentation, florid chaff rash, coffee spots and other diseases, which can be treated by oral medication, medication application and laser. 1. Post-inflammatory hyperpigmentation: If a child’s arm is exposed to strong sunlight, it will easily lead to inflammation of the skin, and after the inflammation subsides, it can be light brown spots. There is no need for special treatment, waiting for its own return to normal. 2. Mottled chaff rash: Mottled chaff rash is usually caused by Malassezia infection, which can lead to the appearance of round, oval light brown patches on the patient’s skin, accompanied by a slight itching sensation. You can apply antifungal drugs, such as ketoconazole ointment, sertaconazole nitrate cream and other drugs for treatment, you can also take oral antifungal drugs, such as itraconazole capsules. 3. Coffee spot: some coffee spots are related to genetic factors, and normal people can also appear in infancy. Generally do not need treatment, if affect the aesthetic can be under the guidance of the doctor for laser treatment, through laser treatment can improve the patient’s skin lesions phenomenon. Children with light brown patches on the arm, patients need to consult a doctor in a timely manner, after clarifying the cause of the cause of treatment.