Lymph nodes are not visible behind the ear in children. If there are swollen lymph nodes, clinically there may be the following cases: i. Inflammatory diseases of the ear itself, commonly associated with inflammatory infections of the ear, acute otitis externa, acute tympanitis, acute otitis media, etc., inflammation spreads to the lymph node system behind the ear, resulting in inflammatory, reactive hyperplasia and enlargement of the lymph nodes, which is clinically the most common. Second, some children with inflammatory diseases of the parotid gland may also have enlarged lymph nodes behind the ear. Some children with inflammatory diseases in other areas, such as acute pharyngitis, acute tonsillitis, or inflammatory diseases in other parts of the body, may have inflammatory changes that involve the lymph nodes behind the ear through the lymphatic system, and may also develop enlargement and enlargement of the lymph nodes behind the ear. Some children with lymph node tuberculosis can also have enlarged lymph nodes behind the ear, while some children with lymphoma can also have enlarged lymph nodes behind the ear.