Sinus Surgery

Most cases of chronic sinusitis develop following an acute sinusitis infection. Most cases of acute sinusitis go away within 2-3 weeks, often much sooner. In some cases the symptoms do not go and become persistent (chronic). The following are causes of acute sinusitis that may progress into a chronic sinusitis:

Cold or flu-like illnesses

In most cases, acute sinusitis develops from a cold or flu-like illness. Colds and flu are caused by germs called viruses which may spread to the sinuses. The infection may remain viral before clearing, causing a viral sinus infection. In a small number of cases, germs called bacteria add on to an infection that started with a virus. This can cause a bacterial sinus infection which can make the infection worse, last longer and may cause more damage or changes to the lining of the sinus.

Dental infections

In some cases, infection spreads to a cheekbone (maxillary) sinus from an infected tooth.

Other risk factors for sinus infection

In few people, one or more factors are present that may cause their sinuses to be more prone to infection. Acute sinusitis may be more likely to progress into chronic sinusitis as there is an underlying problem. Such factors include:

• Nasal allergy (allergic rhinitis). The allergy may cause swelling of the tissues on the inside lining of the nose and block the sinus drainage channels. This makes the sinuses more susceptible to infection. See separate leaflets called Hay Fever and Persistent Rhinitis which discuss allergic rhinitis in more detail.
• Other causes of a blockage to the sinus drainage channels, such as:
  – Growths (nasal polyps).
  – Objects pushed into the nose (especially in children, such as peas or plastic beads).
  – Facial injury or surgery.
  – Certain congenital abnormalities. (‘Congenital’ means you are born with these abnormalities.)
• Asthma.
• Cystic fibrosis.
• A poor immune system – for example, people with HIV, people on chemotherapy, etc. A poor immune system makes you more prone to any infection. Fungal infections are rare causes of sinusitis and occur most commonly in people with a poor immune system.
• Inflammatory disorders such as Wegener’s granulomatosis or sarcoidosis.
• Pregnancy, which makes you more prone to nasal inflammation (rhinitis).
• Primary ciliary dyskinesia/Kartagener’s syndrome.
• Rare tumours of the nose.
• Smoking.
• Diabetes.
• Sniffing substances that irritate the lining of the nose (for example, cocaine).
• Previous injury to the nose or cheeks.

If you develop chronic sinusitis after an acute sinus infection, you may continue to get symptoms even though the infection has gone. (This is why treating chronic sinusitis with a normal course of antibiotics does not often work.) After being initially triggered by an infection, the persisting symptoms may be due to a combination of factors. For example:

• Poor drainage of the affected sinus – the sinus drainage channel may become fully or partially blocked.
• A build-up of mucus in the sinus.
• Inflammatory changes to the lining of the sinus that result from infection.
• A flare-up of infection from time to time as a result of these changes.
  Sometimes, a persisting allergy can cause inflammation in a sinus and swelling or blockage of the drainage channel.