My son is 9 months old,at birth he was having skin tag like structure on anterior lateral side of left neck and pit without any opening on right neck. Pediatrician said skin tag. Pediatric surgeon said 2 nd brachial cleft sinus. ENT specialist told skin tag. So how can we differentiate between two,because I am confused by doctors different diagnosis. What is the treatment for the same,and at what age. Thanku.