Fungal Sinusitis

The sinuses are cavities located within the skull around the nose, under the bones of the cheeks and forehead. Two distinct types of Aspergillus sinusitis exist, both in people who have healthy immune systems:


Allergic fungal sinusitis (or eosinophilic fungal rhinosinusitis). Total obstruction of the sinuses due to inflamed mucosa. Image taken from Aspergillus.org

Allergic Fungal Rhinosinusitis

Symptoms include nasal airway obstruction (difficulty breathing through the nose), allergic nasal congestion (blockage as a result of being exposed to something that the person is allergic to), purulent rhinorrhoea (thick green ‘snot’), postnasal drainage (mucus dripping down the back of the throat from the back of the nose) and headaches. Pain is not usual but, if present tends to indicate an additional bacterial infection of the sinuses. Allergic fungal rhinosinusitis is usually diagnosed using blood tests (to detect antibodies to the fungus), CT scan, endoscopy and culture of samples taken from the sinus. Nasal polyposis is often present (N.B. these are NOT cancerous even though they are described as tumours). This condition is usually treated with steroids and surgery. The steroids are usually continued for some time, as reduction of inflammation inside the nasal passages and sinuses is important to allow natural drainage. Once drainage is optimised, the inflammation usually subsides and eventually steroids can be slowly stopped.

Prognosis

Despite all these efforts patients relapse quite frequently and some doctors have tried treating with antifungal medication to try to eradicate the fungus. Results are confused so far – this is a subject for more research.
In exceptional cases the bones of the sinus can be perforated, allowing the fungus to invade neighbouring sites, such as the eye.

Saprophytic Sinusitis

Sinusitis is defined as inflammation of the paranasal sinuses, with or without infection. Inflammation can be caused by bacterial infection, allergy, virus and fungal infection. Frequently fungal infection is detected once the condition fails to respond to antibiotics (antibiotics are designed to kill bacterial infections, but have no effect on fungal infections). Aspergillus sinusitis is thought to be caused by repeated bacterial infections causing swelling, which restricts the normal drainage of the sinus. Treatment with antibiotics therefore often produces a partial response, as the bacteria die away and the swelling reduces; this leads to many incomplete diagnoses. Symptoms include nasal congestion, facial discomfort, headache and postnasal drainage. Diagnosis is made by CT scans, endoscopy (a tiny camera inserted into the sinuses), or quite frequently during surgery to improve drainage! Treatment is surgery to improve sinus drainage – a major contributing factor to getting the problem in the first place is having a slightly different structure to the sinus, making drainage more difficult. Surgery corrects that fault. Antifungals are not normally used.

Prognosis

Sinusitis can be prone to reoccurrence but this is usually a successful procedure.