If abnormal, the patient is admitted for IV antibiotic therapy. Failure to improve within 24 hours is indication for emergency surgery. The same paradigm is true for sphenoid sinusitis and ethmoid sinusitis with periorbital cellulitis. Recurrent sinusitis is the diagnosis for those who clear the sinus infection, but very shortly after discontinuing antibiotic therapy, develop a new infection. This can be from a narrowed, scared, or otherwise damaged sinus drainage, or it can result from ongoing allergic or other inflammatory rhinitis.
Chronic sinusitis is an entirely different illness.
To understand chronic sinusitis one must understand the mucociliary transport system. The nose and paranasal sinuses are lined with upper respiratory tract epithelium. This is an epithelium with cilia covered by a mucus blanket floating on a layer of saline. Bacteria, irritants and other particulate matter are trapped in the mucus layer and then carried along by the ciliary motion out of the sinuses to the back of the nose, and into the pharynx. If the mucociliary transport system is impaired, the sinuses will be chronically infected.