Since affordable, accurate diagnostic tests are unavailable, differentiating between sinus infections secondary to the viral infections of upper respiratory tract (URT) and acute bacterial rhinosinusitis (ABRS) is difficult. Therefore, both the diseases share signs and symptoms, such as facial pressure, fever, nasal congestion and rhinorrhea. The rhinorrhea and nasal congestion persists for 1-4 weeks in case of ABRS. The symptoms worsen after five / seven days. Other ABRS symptoms include cough, anosmia / hyposmia, ear pressure / fullness, fatigue, maxillary dental pain and postnasal drip

However, the symptoms may not accurately indicate ABRS because complete and direct physical examination of the paranasal sinuses is not possible due to their inaccessible location within the skull. The ABRS symptoms also overlap with those of the sinus disorders due to non-infectious and non-bacterial factors, including diving, anatomical abnormalities obstructing sinus drainage, foreign bodies, polyps, perennial rhinitis and swimming complications.

The worsening allergic rhinitis or URT infections trigger inflammation of the mucous, causing ABRS. The inflammation and secretion retention further encourage bacterial growth.  The small living things (bacteria) causing ABRS of the ethmoid, frontal and maxillary sinuses include Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pneumonaie. Anaerobic streptococci, Bacteroides, coliform bacilli, Proteus and other anerobic bacteria are mainly responsible for acute maxillary sinusitis secondary to dental disorders. The maxillary sinus is more prone to ABRS. The principal cause of acute bacterial rhinosinusitis of the sphenoid sinus is Staphylococcus aureus. Anaerobes, Staphylococcus aureus and other varieties of streptococcus may also cause the disease.

To cure ABRS, sinus drainage shall be restored by eradicating nasal congestion and offending bacteria. If ABRS is unilateral, teeth shall be examined for infections. The treatment for ABRS consists of effective measures to relieve symptoms, mucolytic agents, topical corticosteroids, decongestants and antibiotics. The measures to relieve the symptoms include humidification, nasal irrigation and saline nasal sprays that clear the congestion. Mucolytic agents thin the secretions. Topical corticosteroids reduce the inflammation.

Antibiotics are generally administered to the patients whose symptoms are more than a week old. The patients having two or more symptoms are also given antibiotics. For instance, symptoms improve initially and then deteriorate, and tenderness in maxillary sinus region, facial pain and purulent nasal discharge occur simultaneously. Many patients recover with an appropriate dosage of antibiotics.  Standard antibiotics used for the treatment include amoxicillin, azithromycin, doxycycline and trimethoprim. However, consult your physician before starting medication.