Sinusitis is an infection often caused by viruses, bacteria, or both. It occurs when cold viruses and bacteria enter the sinuses but usually doesn’t cause trouble unless sinus drainage is blocked. This blockage is the primary reason for sinusitis, and restoring drainage is crucial for treatment. Viruses, not bacteria, are the common cause of colds, making antibiotics ineffective against them. However, when a cold develops into sinusitis, it indicates that blocked nasal passages have triggered a secondary bacterial infection, potentially necessitating antibiotic treatment. Fungal infections can also cause sinusitis, especially in individuals with weakened immune systems.

Can an untreated bacterial sinus infection cause long-term issues? If left untreated, a bacterial sinus infection could perpetuate a cycle of sinus blockage, pain, and pressure, leading to further infections and more blockage.

An acute sinus infection, typically following a cold and lasting less than four weeks, is often due to a bacterial infection. Chronic sinusitis, however, persists for more than 12 weeks despite medical treatment and is more common in people with allergic rhinitis or asthma.

To diagnose acute bacterial sinusitis, look for persistent symptoms of an upper respiratory illness, such as rhinorrhea or daytime cough lasting 10 days or more, or severe symptoms at onset including high fever.

To manage sinusitis symptoms initially, use nasal rinses, decongestants, and pain relievers. Sinusitis, an infection of the sinuses near the nose, results in persistent inflammation and blockage of the sinus passages. These infections can follow a viral or bacterial cold, aggressive allergic inflammation, or past surgeries that led to unfavorable healing.

When treating bacterial infection in suspected Acute Bacterial Rhinosinusitis (ABRS), antibiotics are recommended if IDSA criteria for bacterial sinusitis are met. This includes persistent symptoms for 10 or more days, 5-6 days of severe symptoms, or worsening symptoms after initial improvement.

Harvard Health
Harvard Health
Mayo Clinic Health System
Keck Medicine of USC
Infectious Diseases Management Program at UCSF
Stanford Medicine
Stanford Medicine
Hospital Handbook