Common skin condition (sometimes called chicken skin)
These are common in children and adolescents. Seen mostly on the upper outer arms and outer upper thighs, they can also be seen on the cheeks near the ears. They can be itchy but this is likely caused by excessive rubbing. You may notice these in other family members.
These can be self limited and resolve over weeks or months, but may be present for a long time. Treatment suggested is moisturizing creams and lotions. A consult with a dermatologist may be offered to confirm the diagnosis.