Fungal Rhinosinusitis

Last reviewed: 11 March 2026

Overview

The sinuses are air-filled cavities in the skull located around the nose, behind the cheeks, and in the forehead. They connect to the nasal passages and help humidify the air we breathe.

Fungi are present everywhere in the environment and small numbers of fungal spores are inhaled every day. In some people, fungi may grow within the sinuses or trigger inflammation in the sinus lining. When this occurs it is known as fungal sinusitis or fungal rhinosinusitis.

Several different forms of fungal sinus disease exist. Most occur in people with healthy immune systems. These conditions are different from invasive fungal infections seen in severely immunocompromised patients.

The most common non-invasive forms include:

• Allergic Fungal Rhinosinusitis (AFRS)
• Saprophytic fungal colonisation (saprophytic sinusitis)
• Fungal ball (mycetoma)

These conditions vary in severity but often share similar symptoms.

Symptoms

Symptoms of fungal sinusitis are similar to those seen in chronic sinusitis and may include:

• difficulty breathing through the nose
• blocked or congested nose
• thick nasal mucus, often yellow or green
• post-nasal drip (mucus dripping down the back of the throat)
• reduced or lost sense of smell
• facial pressure or pain
• headaches
• fatigue

Symptoms often develop gradually and may persist for months.

Diagnosis

Diagnosis usually requires assessment by an ear, nose and throat (ENT) specialist.

Common tests include:

• CT scan of the sinuses – shows sinus blockage, mucus accumulation or fungal material
• Nasal endoscopy – a small flexible camera inserted into the nose to examine the sinus openings
• allergy testing – blood tests or skin prick tests may detect fungal sensitisation
• laboratory testing of sinus material removed during surgery

These tests help distinguish fungal sinus disease from bacterial sinusitis, nasal polyps, or other sinus disorders.

Types of fungal sinusitis

Fungal sinusitis is usually divided into different types depending on how fungi interact with the sinus lining and immune system.

Allergic Fungal Rhinosinusitis (AFRS)

Overview

Allergic Fungal Rhinosinusitis (AFRS) occurs when the immune system develops a strong allergic reaction to fungi present in the sinuses. The reaction leads to inflammation, thick allergic mucus and blockage of the sinus passages.

The fungi most commonly involved include Aspergillus species and other environmental moulds.

AFRS typically affects people who:

• have asthma or allergies
• are otherwise immunocompetent
• develop chronic sinus inflammation and nasal polyps

Treatment

• steroid medication (often nasal steroids and sometimes oral steroids)
• endoscopic sinus surgery to remove allergic mucus and open the sinus passages
• long-term nasal steroid treatment to reduce inflammation

Management often requires ongoing monitoring by ENT specialists.

Saprophytic Sinusitis

Overview

Saprophytic fungal colonisation occurs when fungi grow on mucus or crusts within the nasal cavity without invading tissue.

The fungi essentially feed on the mucus and organic material present in the nose. This form of fungal sinusitis usually occurs after previous sinus surgery or when mucus crusting develops inside the nose.

It is generally considered the least aggressive form of fungal sinus disease.

Treatment

• removal of fungal crusts or debris
• nasal cleaning and saline rinses
• occasionally minor surgical removal of fungal growth

Antifungal medications are usually not required.

Prognosis

Most forms of fungal sinusitis can be successfully managed, particularly when diagnosed early.

However, conditions such as AFRS can be prone to recurrence. Long-term monitoring and maintenance treatment (such as nasal steroid sprays or saline irrigation) may be needed to reduce inflammation and prevent sinus blockage.

Many patients experience significant improvement in symptoms after sinus surgery combined with medical treatment.

Common questions

Is fungal sinusitis contagious?

No. Fungal sinusitis cannot be passed from one person to another.

Do antifungal medicines always treat fungal sinusitis?

Not always. Many forms of fungal sinus disease are caused by allergic reactions rather than active fungal infection, so treatment often focuses on reducing inflammation and clearing the sinuses.

Is fungal sinusitis linked to asthma?

Yes. Some people with allergic fungal rhinosinusitis also have asthma or fungal allergies.

Will it come back after treatment?

Some types, especially AFRS, can recur. Long-term monitoring and ongoing treatment may be needed.

When to seek medical advice

Seek medical advice if you experience:

• persistent sinus symptoms lasting longer than 12 weeks
• severe facial pain or swelling
• blocked nose that does not improve with treatment
• recurrent sinus infections
• reduced sense of smell or taste

Urgent medical care is required if sinus symptoms are accompanied by visual changes, severe headache, or neurological symptoms.

Author and review information

References

1. deShazo RD, Swain RE. Diagnostic criteria for allergic fungal sinusitis. J Allergy Clin Immunol. 1995 Jul;96(1):24-35. doi: 10.1016/s0091-6749(95)70029-3. PMID: 7622760.
2. Fokkens WJ, Lund VJ, Hopkins C., et. al. European Position Paper on Rhinosinusitis and Nasal Polyps 2020. Rhinology. 2020 Feb 20;58(Suppl S29):1-464. doi: 10.4193/Rhin20.600. PMID: 32077450.
3. Ponikau JU, Sherris DA, Kephart GM, Adolphson C, Kita H. The role of ubiquitous airborne fungi in chronic rhinosinusitis. Curr Allergy Asthma Rep. 2005 Nov;5(6):472-6. doi: 10.1007/s11882-005-0028-6. PMID: 16216172.