The black edges of young children’s lips may be due to pigmentation, lipitis and lead poisoning. 1. Pigmentation: If a toddler has black lips without other discomfort and has the bad habit of licking his lips, it may be due to the stimulation of the surface tissues around the lips and the production of excessive melanin resulting in pigmentation around the lips. 2. Lipitis: young children with lipitis, because the skin cells around the lips are stimulated by inflammatory factors for a long time, excessive keratinization or pigmentation, so there will be a black lip. 3. Lead poisoning: some young children with lead poisoning will have black lips. If your toddler has black lips, you should take your toddler to the hospital in time to clarify the cause and standardize the treatment.