Children with purple gums are considered to be caused by exogenous staining, eruptive cysts, heavy metal poisoning, etc. It is recommended to go to the hospital in time to clarify the cause of the disease. 1. Exogenous staining: If parents let their children eat foods that are too dark in color, such as pomegranate, dragon fruit, etc., it may cause the child’s gums to be temporarily stained purple. 2. Emergence cysts: When a child’s teeth are erupting, he or she may have an eruption cyst, in which the mucous membrane covering the tooth appears swollen and is purple or greenish or purplish-black in color. An eruptive cyst is mainly due to the presence of tissue fluid or blood oozing between the gums and teeth. No special treatment is usually needed. If the cyst becomes bigger and the tooth can not erupt, it should go to the hospital in time, and the doctor will cut and drain it. 3. Heavy metal poisoning: Heavy metal poisoning may cause your child’s gums to turn purple. If the child has uncomfortable symptoms, should go to the hospital in time to avoid delay or cause adverse reactions.