There are many reasons why babies have small red dots on their arms and faces, and the common ones are prickly heat, eczema, allergic diseases, infectious diseases and other reasons. 1. prickly heat: due to the baby’s delicate skin, and sweat gland function is not yet fully developed, if the child is dressed too thick or bedding is too thick, may cause excessive sweating, sweat discharge is not smooth, will lead to the body long prickly heat, caused by the baby arm and face with small red dots. 2. Eczema: Inflammatory skin reactions caused by internal and external stimuli may also lead to red dots on the baby’s arms and face. 3. contact dermatitis: contact dermatitis is an inflammatory reaction that occurs after the skin has come into contact with certain substances, and babies who come into contact with certain irritating (soap, laundry detergent, etc.) or allergic (certain plants, cosmetics, etc.) substances when playing can also cause babies to have small red dots on their arms and faces. 4. Infectious diseases: bacterial infections caused by skin folliculitis, fungal infections caused by ringworm, viral infections caused by chickenpox, herpes, measles, hand, foot and mouth disease, toddler emergency rashes, rubella, etc. will also cause the baby arm and face with small red spots. Red dots on baby’s arms and face, there may be other reasons, need to go to the hospital in time for further examination to clarify the cause of the disease.