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Nose and sinuses MediBilbao Salud

Fungal Sinus Infection: Types, Symptoms, Diagnosis and Treatment

Most sinus infections are caused by viruses or bacteria, but fungi can also affect the sinuses. Fungal sinus disease covers several different conditions: some are slow and non-invasive, like a fungal ball in one sinus or an allergic reaction to fungi, and others are rare but serious invasive infections in people with weakened immunity. Because the treatment is very different from that of an ordinary sinus infection, it is important to recognise when a fungus may be involved. This guide explains, from an ear, nose and throat (ENT) point of view, the types, symptoms and treatment.

Topic
ENT
Updated
Reading time
5 minutes
Reviewed by
Dr. Itziar Gotxi Erezuma · Medical doctor (ENT) · Bizkaia Medical Association no. 484809757

Types of fungal sinus infection

  • Fungal ball (mycetoma): a dense collection of fungal material, most often Aspergillus, in a single sinus. It does not invade tissue and usually affects healthy, middle-aged or older adults, sometimes after dental work on upper teeth.
  • Allergic fungal rhinosinusitis: an allergic inflammatory reaction to fungi, typically in younger people with allergies or asthma, causing nasal polyps and thick, peanut-butter-like mucus.
  • Saprophytic fungal infestation: fungus growing on crusts in the nose, often after surgery; treated by cleaning.
  • Chronic invasive fungal sinusitis: slow invasion of tissue over months, rare, in people with diabetes or mild immune problems.
  • Acute invasive fungal sinusitis: rapid invasion over days in people with severely weakened immunity; a medical emergency.

Symptoms

  • Nasal blockage and discharge, often on one side only.
  • Thick, dark, brown, green or black mucus; see black mucus.
  • Facial pain or pressure, often over the cheek.
  • Bad smell in the nose or bad taste.
  • Reduced sense of smell, especially with polyps.
  • In invasive forms: fever, facial swelling, numbness of the face or palate, black crusts or ulcers in the nose or mouth, swelling around the eye, double vision or loss of vision.

Many symptoms overlap with ordinary chronic sinusitis; see sinus infection symptoms. One-sided symptoms that do not respond to standard treatment are a clue to look for a fungal or other cause.

Who is at risk

  • Fungal ball: older adults, dental fillings or root canal treatment in upper teeth, sometimes with no clear risk factor.
  • Allergic fungal sinusitis: people with allergies, asthma and nasal polyps, more common in warm, humid climates.
  • Invasive fungal sinusitis: poorly controlled diabetes (especially with ketoacidosis), chemotherapy, bone marrow or organ transplants, long-term high-dose steroids and other causes of weakened immunity.

How it is diagnosed

An ENT specialist examines the nose with an endoscope, looking for polyps, thick mucus, crusts or areas of dead tissue. A CT scan of the sinuses is the key test: a fungal ball typically shows one opaque sinus with dense spots, and allergic fungal sinusitis shows expanded sinuses filled with dense material. MRI helps assess spread to the eye or brain in invasive disease.

Samples of mucus or tissue are examined under the microscope and cultured to identify the fungus. In invasive disease, a biopsy confirms fungal invasion of tissue and must be done urgently.

Treatment depends on the type

  • Fungal ball: removal with endoscopic sinus surgery through the nose, which is usually curative. Antifungal medicines are not needed.
  • Allergic fungal sinusitis: endoscopic surgery to remove polyps and fungal mucus and open the sinuses, followed by steroid nasal rinses or sprays, sometimes oral steroids, and long-term follow-up because it can recur. Biologic medicines may be considered in difficult cases.
  • Saprophytic infestation: cleaning of crusts and saline rinses.
  • Invasive fungal sinusitis: emergency treatment with intravenous antifungal medicines, urgent surgery to remove infected tissue, and correction of the underlying problem, such as controlling blood sugar.

Antibiotics treat bacteria, not fungi, so repeated antibiotic courses do not help fungal sinus disease. Over-the-counter antifungal products are not a treatment for sinus fungal disease.

Can it be prevented?

Fungal spores are everywhere and cannot be avoided completely. For most people, good control of allergies and asthma, saline rinses and treatment of chronic sinusitis help keep the sinuses healthy. People with diabetes should aim for good blood sugar control, and people with weakened immunity should report any new nasal, facial or eye symptoms to their medical team promptly.

When to seek urgent help

  • Facial swelling, numbness or severe pain with fever.
  • Black crusts or ulcers inside the nose or on the roof of the mouth.
  • Swelling around the eye, double vision or reduced vision.
  • Confusion, severe headache or neck stiffness.
  • Any of these symptoms in a person with diabetes, cancer treatment or a transplant: emergency care the same day.

See an ENT specialist (not urgently) for one-sided blockage, discharge or bad smell lasting more than three weeks.

Key points to remember

  • Fungal sinus disease ranges from a harmless fungal ball to rare invasive infections.
  • One-sided symptoms and dark, thick mucus that do not respond to treatment are clues.
  • Fungal balls and allergic fungal sinusitis are treated with endoscopic surgery.
  • Invasive fungal sinusitis in people with weakened immunity is an emergency.

Questions about fungal sinus infections

These answers are general information and do not replace an examination or individual medical advice.

How do I know if my sinus infection is fungal?

Clues include one-sided symptoms, thick dark mucus, polyps and no response to antibiotics. A CT scan and endoscopy confirm it.

Is a fungal sinus infection contagious?

No. Fungal sinus disease is not passed from person to person.

Can a fungal sinus infection go away on its own?

Fungal balls and allergic fungal sinusitis usually need surgery. They do not clear with antibiotics.

Is a fungal sinus infection dangerous?

Non-invasive forms are not dangerous but cause symptoms. Invasive forms in people with weakened immunity are serious and need emergency care.

What fungus causes sinus infections?

Aspergillus is the most common. Others include Mucorales in invasive disease and various moulds in allergic fungal sinusitis.

Do antifungal sprays cure fungal sinusitis?

Not on their own. Surgery is the main treatment for non-invasive forms, and invasive forms need intravenous antifungals and surgery.

Sources

  1. NHS · Sinusitis (sinus infection)
  2. NHS · Aspergillosis
  3. Chakrabarti A, et al. Fungal rhinosinusitis: a categorization and definitional schema addressing current controversies. Laryngoscope. 2009

This guide is for general information and does not replace medical advice. How a problem is diagnosed and treated depends on your examination and medical history. If you think you have an emergency, contact your local emergency services.