Purple bags under the eyes of a 4-year-old girl may be caused by heredity, or it may be caused by allergic rhinitis and fracture of the anterior cranial fossa. 1. Heredity: some of the characteristics of children are actually related to heredity, if the parents also have purple bags under the eyes, then the child’s purple bags under the eyes may be caused by heredity. 2. Allergic rhinitis: Allergic rhinitis is a disease mediated by IgE. After the body comes into contact with pollen, dust and other allergens, it leads to inflammatory reactions in blood vessels, and the common symptom of purple bags under the eyes will appear. 3. Anterior cranial fossa fracture: the anterior cranial fossa fracture may be caused by trauma, after the fracture, the eyelids in the orbit will be congested, resulting in the skin and mucous membranes of the eye bags are bruised and purple. Purple bags under the eyes of a 4-year-old girl may also be seen in respiratory infections, trauma and other diseases, if the symptoms of purple bags under the eyes of a 4-year-old girl with other discomforts, you need to seek medical treatment.