Does bacterial sinusitis cause fever?

From the Guidelines

Bacterial sinusitis can cause fever, and it is more likely when symptoms persist for more than 10 days without clinical improvement, symptoms are severe, or symptoms worsen after an initial period of improvement. According to the study by 1, a bacterial cause is more likely when symptoms persist for more than 10 days without clinical improvement, symptoms are severe (fever >39 °C, purulent nasal discharge, or facial pain lasting for >3 consecutive days), or symptoms worsen after an initial period of improvement.

Key Points to Consider

• Fever is more common in acute bacterial sinusitis than in viral or chronic cases
• When present, the fever typically ranges from low-grade (99-100.9°F or 37.2-38.3°C) to moderate (101-103°F or 38.3-39.4°C)
• Other symptoms that often accompany bacterial sinusitis include facial pain or pressure, nasal congestion, thick yellow or green nasal discharge, post-nasal drip, and headache
• If symptoms worsen after initially improving, or if fever is high or persistent, medical attention should be sought as antibiotics may be necessary

Management Strategies

• Common antibiotics prescribed for bacterial sinusitis include amoxicillin (500mg three times daily for 5-10 days) or amoxicillin-clavulanate if drug resistance is suspected
• While managing symptoms, staying hydrated and considering using saline nasal irrigation and over-the-counter pain relievers like acetaminophen or ibuprofen can help reduce fever and discomfort
• The American Academy of Otolaryngology–Head and Neck Surgery emphasizes watchful waiting (without antibiotic therapy) as initial management for all patients with uncomplicated ABRS, regardless of severity, as stated in the study by 1

Diagnostic Considerations

• Radiographic imaging of the paranasal sinuses is unnecessary for diagnosis in patients who already meet clinical diagnostic criteria for ABRS, as stated in the study by 1
• Imaging studies may be obtained when a complication of ABRS or an alternative diagnosis is suspected, such as orbital, intracranial, or soft tissue involvement.

From the Research

Bacterial Sinusitis and Fever

• Bacterial sinusitis is often characterized by specific symptoms, including fever, as noted in a study published in 2025 2.
• The study states that cardinal features of acute bacterial rhinosinusitis include unilateral facial pain or pressure, fever greater than 102°F (39°C), and purulent nasal discharge with obstruction of the nasal passages.
• Another study from 2018 does not specifically address the relationship between bacterial sinusitis and fever, but it discusses the treatment of acute bacterial sinusitis with amoxicillin/clavulanate 3.
• A 1998 study comparing the efficacy of amoxicillin and clavulanate given every 12 hours versus every 8 hours for the treatment of acute bacterial maxillary sinusitis does not mention fever as a symptom or outcome measure 4.
• Similarly, studies from 2000 and 1999 discuss the medical management and treatment of acute bacterial sinusitis, but they do not provide direct evidence on the relationship between bacterial sinusitis and fever 5, 6.
• However, based on the information provided in the 2025 study, it can be inferred that fever is a symptom associated with bacterial sinusitis 2.