ABSTRACT
I. Background 451
II. Pathophysiology 452
III. Diagnosis 452
IV. Microbiology 453
V. Treatment 454
References 456
I. Background
Acute sinusitis is defined as an inflammatory reaction of the mucosal lining of the
sinuses that is present for ,30 days. Such a reaction can be infectious or noninfectious and suppurative or nonsuppurative. Frontal, ethmoid, maxillary,
or sphenoid sinuses may be involved. Although the development of ethmoidal
and maxillary sinuses begins in the fetus and continues through late adolescence,
they are difficult to detect by X-ray before the second year of life. The sphenoid
sinuses are developed by the third year; the frontal sinuses are rarely a site of
infections until 6 years of age (1,2). Viral rhinosinusitis is at least 20-200
times more common than bacterial sinusitis (3,4). Therefore, the diagnosis of
Unidad de Investigacio´n en Medicina Tropical y Salud Internacional, Instituto de Salud Carlos III, Madrid, Spain.
