In a URI, the swollen nasal mucous membrane obstructs the ostium of a paranasal sinus, and the O 2 in the sinus is absorbed into the blood vessels of the mucous membrane. An outpouring of serum and leukocytes to combat the infection results, and painful positive pressure develops in the obstructed sinus. The mucous membrane becomes hyperemic and edematous. Symptoms, Signs, and Diagnosis Acute sinusitis and chronic sinusitis produce similar symptoms and signs. The area over the affected sinus may be tender and swollen.
Maxillary sinusitis causes pain in the maxillary area, toothache, and frontal headache.
Frontal sinusitis produces pain in the frontal area and frontal headache. Ethmoid sinusitis causes pain behind and between the eyes and a frontal headache often described as splitting. Pain from sphenoid sinusitis is less well localized and is referred to the frontal or occipital area. Malaise may be present. Fever and chills suggest an extension of the infection beyond the sinuses.