Sinus Infection Treatment in Bangkok: Rhinosinusitis Care That Actually Works
How Doctor Bangkok distinguishes a viral cold from bacterial rhinosinusitis, and treats each correctly.
Clinically reviewed by Dr. Ponlawat Pitsuwan, Physician, Doctor Bangkok
Sinus infection, or rhinosinusitis, is inflammation of the paranasal sinuses that causes facial pressure, nasal obstruction, thick discharge, and reduced sense of smell. Most cases are viral and resolve in 7 to 10 days; only about 2 percent become bacterial. At Doctor Bangkok we apply the IDSA and EPOS 2020 criteria, offer symptomatic treatment with saline irrigation and intranasal corticosteroids first, and reserve amoxicillin-clavulanate for cases that meet the bacterial threshold.
From the clinic: Sinus pressure is one of the most over-antibiotic-treated symptoms in primary care. Patients arrive expecting a 5-day course, and a decade ago they would have been handed one. In 2026 the evidence is clear: most rhinosinusitis is viral, antibiotics do not shorten it, and giving them anyway feeds resistance. My job in clinic is to tell apart the patients who actually need antibiotics from the majority who will do better on saline rinses and a steroid spray.
What rhinosinusitis actually is
The paranasal sinuses are air-filled cavities in the face that drain into the nose. When the lining inflames from a virus, allergy, or bacterial infection, drainage blocks and pressure builds behind the cheeks, forehead and eyes. Acute rhinosinusitis lasts under 4 weeks, subacute 4 to 12 weeks, and chronic rhinosinusitis 12 weeks or more. Most acute cases follow a common cold, which is why symptoms typically start with runny nose and mild congestion before pressure becomes the dominant complaint.
| Viral rhinosinusitis | Bacterial rhinosinusitis |
|---|---|
| Peaks day 3 to 5, improves by day 10 | Symptoms persist beyond 10 days |
| Clear to yellow discharge | Purulent nasal discharge |
| Mild to moderate facial pressure | Severe facial pain, maxillary tenderness |
| Low-grade fever or none | Fever above 39 degrees C |
| Steady improvement | Double-sickening pattern |
| Saline + steroid spray | Amoxicillin-clavulanate first line |
Viral vs bacterial: the EPOS and IDSA criteria
The practical test is time and pattern. Viral rhinosinusitis peaks at day 3 to 5 and improves by day 10. Bacterial rhinosinusitis is suspected if symptoms persist beyond 10 days without improvement, if they are severe from the start with fever above 39 degrees Celsius and purulent discharge, or if they double-sicken, meaning they improve and then worsen around day 5 to 6. Only this subset benefits from antibiotics, per the Infectious Diseases Society of America 2012 guideline and the European Position Paper on Rhinosinusitis (EPOS 2020). If you are unsure whether you fit this picture, start with our overview page on upper respiratory infections.
How we treat it at Doctor Bangkok
For viral and early bacterial cases we recommend high-volume saline nasal irrigation (a neti pot or squeeze bottle), an intranasal corticosteroid such as fluticasone or mometasone, paracetamol or ibuprofen for pain, and oral pseudoephedrine for short-term decongestion in patients without hypertension. When criteria for bacterial rhinosinusitis are met we prescribe amoxicillin-clavulanate as first line, doxycycline or levofloxacin in penicillin-allergic patients. Short-acting topical decongestants like oxymetazoline can be used for up to 3 days only, because longer use causes rebound congestion (rhinitis medicamentosa). Many patients with overlapping flu symptoms or an underlying allergy benefit from treating both at once.
When to see a doctor
Book an appointment if facial pressure and nasal discharge last more than 10 days without improvement, if symptoms worsen after an initial improvement, or if you have fever above 39 degrees with severe pain. Seek same-day care for swelling or redness around the eye, double vision, a stiff neck, severe headache with confusion, or any visual change. These are red flags for orbital cellulitis, cavernous sinus thrombosis, or intracranial extension and need imaging and hospital review, not a phone consult. Recurrent sinus infections (more than four per year) also warrant investigation for allergy, structural obstruction, or immune issues.
Red flag: If red-flag symptoms appear, do not wait. Book same-day or present to the nearest emergency department as described above.
Prevention and self-care
Daily saline irrigation genuinely reduces both frequency and severity of rhinosinusitis in people prone to it. Controlling underlying allergic rhinitis with a daily intranasal steroid is the single most effective prevention strategy; do not stop it the moment you feel better. Keep humidity moderate, avoid cigarette smoke, and stay up to date on influenza and COVID-19 vaccinations since post-viral rhinosinusitis follows those infections. If you dive or fly frequently and get blocked sinuses on descent, a preventive dose of pseudoephedrine or a topical decongestant 30 minutes before travel is reasonable for short-term use.
Summary
Most sinus infections do not need antibiotics; the ones that do need the right antibiotic at the right time. The clinical value of a visit is in distinguishing those two groups correctly and treating the inflammation rather than chasing a prescription. As Dr. Pitsuwan puts it: “Saline rinses are boring, but they outperform half the antibiotics prescribed for sinusitis in published trials.” Doctor Bangkok offers same-day assessment from our Sukhumvit clinic and as part of our wider 24/7 medical services.
Frequently asked questions
How long does a sinus infection last?
Viral rhinosinusitis usually peaks at day 3 to 5 and resolves by day 10. Bacterial cases can last 2 to 4 weeks and are suspected when symptoms persist beyond 10 days or double-sicken after an initial improvement.
Do I need antibiotics for a sinus infection?
Only if the pattern fits bacterial rhinosinusitis: symptoms lasting more than 10 days without improvement, severe onset with high fever and purulent discharge, or double-sickening. Most cases do not meet these criteria.
What colour is snot supposed to be?
Green or yellow mucus does not by itself mean bacterial infection. It reflects neutrophils in the discharge and is common in both viral and bacterial cases. Duration and pattern matter more than colour.
Can I fly with a sinus infection?
Flying with a blocked sinus can cause sinus barotrauma, pain and sometimes bleeding. If you must fly, use a topical decongestant 30 minutes before descent and take paracetamol beforehand. Postpone if you can.
What is the best nasal spray for sinusitis?
Daily intranasal corticosteroid sprays such as fluticasone or mometasone are first-line for both acute and chronic sinusitis. They are safe for long-term use. Topical decongestants like oxymetazoline are for 3 days maximum.
When should I worry about a sinus headache?
Visual changes, swelling or redness around the eye, confusion, stiff neck, or fever above 39 with severe headache need urgent review. These suggest orbital or intracranial complications.
Sources
- Infectious Diseases Society of America (IDSA). Clinical Practice Guideline for Acute Bacterial Rhinosinusitis in Children and Adults, 2012.
- European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS 2020). European Rhinologic Society.
Sinus infection, sinusitis, rhinosinusitis, acute bacterial rhinosinusitis, ABRS, viral rhinosinusitis, paranasal sinuses, maxillary sinus, frontal sinus, ethmoid sinus, sphenoid sinus, nasal congestion, facial pressure, purulent discharge, post-nasal drip, anosmia, hyposmia, double sickening, IDSA 2012, EPOS 2020, amoxicillin-clavulanate, doxycycline, levofloxacin, saline nasal irrigation, intranasal corticosteroid, fluticasone, mometasone, pseudoephedrine, oxymetazoline, rhinitis medicamentosa, orbital cellulitis, cavernous sinus thrombosis, Dr. Ponlawat Pitsuwan, Doctor Bangkok.