Should I worry about my childs sinuses/allergies? My 6yr old daughter gets severe symptoms when congestion or allergy irritation occurs (frequently).

Get her to the doc.. If your child is having frequent and severe symptoms..Of any type..I would have her evaluated for causes and possible treatment etc..Why let her suffer? If allergies, there are plenty of good treatment options. Significant allergies can affect quality of life, sleep, school performance etc...So get her checked...Good luck..
Be Concerned. Chrnic nasal congestion can cause chronic mouth breathing and permanent changes to the structure of the face. But most imp[ortantly affect sleep arousability and decrease the quality of life. I would get the child tested and then treat accordingly.