Accurate Diagnosis and Treatment Approach in Acute Sinusitis: When Is a CT Scan Necessary?

Sinuses are air-filled bony cavities located around our nose. These structures, connected to the respiratory tract, help humidify and warm the air and contribute to voice resonance.

Acute sinusitis is a common condition that typically occurs during seasonal transitions or after upper respiratory tract infections, presenting with complaints such as nasal congestion, facial pain, and discharge. Acute sinusitis is a temporary condition caused by infection, where symptoms usually last less than 4 weeks. However, the biggest mistake is evaluating the condition with a CT scan right at the onset or hastily starting aggressive treatments. In this article, we will explain the correct timing for diagnosis and treatment in acute sinusitis, common mistakes, and when advanced testing is necessary.

When Is a CT Scan Necessary in Acute Sinusitis?

One of the most frequently asked questions by patients is whether computed tomography (CT) is needed for the diagnosis of sinusitis. However, it should be noted that performing a CT scan at the onset of acute sinusitis is not an appropriate approach. Because:

  • In a newly started infection, edema may be observed in the sinuses, which may not always reflect an actual inflammation.
  • A CT scan taken within 7–10 days after treatment begins is too early to reflect the course of the disease and may be misleading.
  • Moreover, CT scans can lead to unnecessary radiation exposure, especially in children and young adults.

Therefore, CT should only be considered in the following cases:

  • In cases of chronic sinusitis lasting longer than 12 weeks or frequently recurring sinusitis,
  • If eye complications such as redness or swelling around the eyes develop,
  • If there is suspicion of brain complications such as severe headache or changes in consciousness.

Most Common Microbes in Acute Sinusitis

The three most commonly encountered bacteria in acute sinusitis are:

  • Streptococcus pneumoniae
  • Haemophilus influenzae
  • Moraxella catarrhalis

Unfortunately, it is often not possible to directly obtain cultures from the sinuses. Therefore, treatment is typically initiated with standard antibiotics that cover these three bacteria. However, if the patient shows a poor clinical response, the antibiotic may need to be changed.

In some patients, for instance, Strep. pneumoniae may be dominant, while in others, different bacteria may be more prominent. This can affect the choice of antibiotics during the treatment process.

Is Antibiotic Treatment Necessary?

Antibiotics are not necessary for every sinusitis case. Especially during the summer months, in patients exposed to sea water or saltwater entering the nose, the issue may be only nasal irritation or temporary mucosal edema. Starting antibiotics immediately in such cases is not appropriate.

It should be remembered that:

  • Sinuses have a natural self-cleansing mechanism.
  • Unnecessary use of antibiotics leads to antibiotic resistance.
  • Mild sinusitis can resolve with just saline sprays, nasal cleaning, and supportive treatments.

The situations in which antibiotics should be started can be summarized as follows:
If symptoms persist for more than 10 days, or if there was initial improvement followed by worsening (secondary worsening), antibiotic treatment may be necessary.

Treatment Duration and Supportive Approaches

Treatment of acute sinusitis generally lasts at least 10 days, and in some patients, it can continue for 4–6 weeks. In particularly resistant cases, the following supportive approaches are of great importance:

  • Nasal rinses (isotonic or hypertonic saline)
  • Nasal steroid sprays (for anti-inflammatory effect)
  • Antihistamine treatments (especially if there is a history of allergy)
  • Decongestant nasal sprays (only for short-term use)

In some cases, if the disease does not resolve despite treatment, changing the antibiotic may be necessary. In such cases, the physician should re-evaluate the patient and, if necessary, switch to alternative antibiotic agents.

Anatomical and Immune Factors

Each patient’s condition is different. Many factors can influence the course of acute sinusitis:

  • Internal nasal anatomical narrowings (such as septum deviation, enlarged middle turbinate)
  • Individual differences in mucosal structure and congenital sensitivity
  • General condition of the immune system

Therefore, even young and healthy individuals can sometimes experience resistant sinusitis. In such cases, a detailed ear, nose, and throat examination, endoscopic evaluation, and advanced imaging methods should be used when necessary.

Conclusion: Avoid Unnecessary CT Scans and Antibiotic Use

Acute sinusitis is usually diagnosed through clinical examination. Early CT scans should be avoided, and antibiotics should not be started in every case. Patience is important during the treatment process, with particular attention given to nasal supportive therapies.

Antibiotics should only be used when necessary to prevent resistance. Healthy sinus function depends not only on medication but also on maintaining nasal hygiene and supporting the physiological functions of the nose.

Prof. Dr. Gediz Murat Serin
Otorhinolaryngology Specialist
Nasal Function and Endoscopic Sinus Surgery

Prof. Dr. Gediz Murat Serin

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