Three-month-old babies scratching their ears and cheeks may be caused by high temperature, eczema in the external ear canal and vitamin D deficiency. 1. Excessive temperature: If the environmental temperature of the three-month-old baby is too high, it will lead to a lot of sweating on the baby’s head, and the stimulation of sweat will make the baby feel uncomfortable, which will be manifested as scratching ears and cheeks. 2. Eczema of the external auditory canal: it is a common allergic inflammatory skin disease that occurs in infants and young children. Patients will appear in the external ear canal skin with erythema, granular papules, small blisters, can be accompanied by itching, so three-month-old babies will be through the ear scratching to relieve the symptoms of itching. 3. Lack of vitamin D: three-month-old babies who lack vitamin D, it is likely to induce vitamin D deficiency rickets, resulting in more sweating in the head, due to sweat stimulation leading to scalp itching, there will be scratching the ears and cheeks, can also be accompanied by easy to wake up, crying, occipital baldness and other symptoms. Three-month-old baby scratching, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.