From the Guidelines
Less than 2% of viral upper respiratory tract infections are complicated by acute bacterial rhinosinusitis (ABRS), indicating that only a small percentage of acute sinusitis cases are bacterial in nature. This is based on the findings from a 2016 study published in the Annals of Internal Medicine 1. The study highlights that acute rhinosinusitis is usually caused by a viral pathogen, and ABRS is considered a secondary infection resulting from obstruction of the sinus ostia.
Key points to consider in diagnosing bacterial sinusitis include:
- Clinical signs and symptoms, such as symptoms persisting for more than 10 days without clinical improvement, severe symptoms (fever >39 °C, purulent nasal discharge, or facial pain lasting for >3 consecutive days), or symptoms worsening after an initial period of improvement (double sickening) for more than 3 days 1.
- The lack of a simple and accurate diagnostic test for ABRS, making clinical guidelines recommend using clinical signs and symptoms to differentiate bacterial from viral causes 1.
- Radiographic imaging has no role in ascertaining a bacterial cause, with radiologic findings having a sensitivity of 90% in detecting a bacterial cause but a specificity of only 61% 1.
Given the low percentage of bacterial cases, healthcare providers often recommend symptomatic treatment first, including saline nasal irrigation, intranasal corticosteroids, and analgesics, before considering antibiotics, as stated in the 2012 IDSA clinical practice guidelines and emphasized by the American Academy of Otolaryngology–Head and Neck Surgery 1. This approach helps reduce unnecessary antibiotic use and prevents antibiotic resistance while effectively managing the majority of sinusitis cases that will resolve without antibiotics.
From the Research
Definition and Causes of Sinusitis
- Sinusitis is defined as inflammation of one or more paranasal sinuses, most often the maxillary sinus 2.
- It is estimated that 0.5-5% of colds are complicated by acute sinusitis 2.
- The most common bacterial isolates from children and adult patients with community-acquired acute bacterial sinusitis are Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pyogenes 3, 4.
Percentage of Bacterial Sinusitis
- Most sinus infections are viral, and only a small percentage develops a secondary bacterial infection 3, 4.
- Up to 1 in 20 upper respiratory tract infections is complicated by bacterial sinusitis 2.
- The exact percentage of acute sinusitis cases that are bacterial in nature is not specified in the provided studies, but it is acknowledged that bacterial sinusitis is a common community-acquired infection 2.
Treatment and Management
- Early diagnosis and appropriate antibiotic therapy, in combination with agents that relieve nasal congestion, are important factors in preventing suppurative complications 2.
- Empiric antibiotic therapy should provide adequate coverage against the most important pathogens 2.
- The duration of treatment of acute sinusitis is inconsistent between different guidelines, but usually a 10- to 14-day treatment course is recommended 2.