Pediatric Infectious Disease Terminology Cellosaurus Disease Terminology Sinusitis Chronic Sinusitis C0149516 Cellosaurus Chronic Sinusitis Sinusitis that lasts more than thirty days without improvement. Chronic_Sinusitis Inflammation of the paranasal sinuses that typically lasts beyond eight weeks. It is caused by infections, allergies, and the presence of sinus polyps or deviated septum. Signs and symptoms include headache, nasal discharge, swelling in the face, dizziness, and breathing difficulties. NICHD Chronic Sinusitis C35151 Disease or Syndrome NICHD Terminology