Pediatric lymph node enlargement in the neck, mainly manifested as swelling and pain in the neck, generalized fever and other symptoms, can be clarified by performing neck ultrasound. Differential diagnosis is needed with the following diseases: 1. Mumps. It is an infectious disease with swelling of the neck centered on the earlobe, and the pain is aggravated when eating acidic food. 2. Congenital oblique neck. The swollen hard mass can be palpated on one side of the neck, which is olive-shaped and poorly mobile, and is present after birth, and can be accompanied by head deviation to the same side, which can be clarified by neck ultrasound. Therefore, it is best to take your baby to the hospital for relevant examinations to clarify.