Sinuses are air filled cavities located in the bones of the face. The sinuses can become infected or inflamed, a condition known as sinusitis. These infections are caused by a blockage of the natural drainage openings of the sinuses. Such blockages can occur when your child has a cold, flu, allergies or bacterial infection. If your child has recurrent sinus infections over a short period of time, has had a complicated sinus infection or has chronic sinusitis that does not resolve with medical therapy, sinus surgery may be discussed as an option to reduce further infection.