Allergic Fungal Sinusitis

A Different Form of Fungal Sinusitis

Mold growth on wall and door.
Mold growth on wall and door. Ekspansio/Getty Images

What is Allergic Fungal Sinusitis (AFS)

Chronic sinusitis is a case of sinusitis that last for 12 or more weeks. It is a prevalent condition in the United States and causes symptoms such as a stuffy nose, post nasal drip, facial fullness and fatigue.

Unlike acute sinusitis, chronic sinusitis tends to be more difficult to cure and the causes are not as well understood. Some known causes include resistant infections, structural abnormalities, and allergies.

A specific type of allergic reaction which occurs in response to airborne fungal particles has also been found to cause chronic sinusitis and can be referred to as allergic fungal sinusitis.

This type of sinusitis should not be confused with other 3 types of fungal sinusitis, as they are caused by an active fungal infection. Rather than having an active infection, the immune system of certain individuals overreacts to inhaled fungal debris and the immune response causes inflammation and edema in the nasal and sinus cavities.

As inflammation and edema causes the sinuses to become blocked, unable to drain and devoid of air, fungal particles are able to grow and multiply, continuing to trigger and perpetuate the immune response. This cycle becomes chronic and can only be broken with proper diagnosis and treatment.

Symptoms of Allergic Fungal Sinusitis

  • post nasal drip
  • very thick mucous
  • purulent nasal discharge (contains pus)
  • fatigue

Changes to the shape of the face sometimes occur but often go unnoticed by both the individual and their family members due to their gradual nature. Pain, other than headaches is unusual in allergic fungal sinusitis. In rare cases, allergic fungal sinusitis, can spread to neighboring areas such as the opthalmic nerve (one of the nerves of the eye) and cause symptoms such as vision loss.

In the few individuals in which this has occurred the symptoms resolved following surgical removal of the fungal growth to treat their condition.

Diagnosing Allergic Fungal Sinusitis

Even medical professionals may have difficulty differentiating between allergic fungal sinusitis and sinusitis that is caused by a fungal infection, but the following findings help to make a clear diagnosis:

  • mucin - the mucous in allergic fungal sinusitis, sometimes called allergic mucin, is distinctly thick and shows other distinctive characteristics when analyzed in a laboratory
  • laboratory findings in allergic fungal sinusitis may show increased levels of immune system components including eosinophilia, elevated total immunoglobulin E (IgE) levels, and immediate skin reactivity or serum immunoglobulin G (IgG) antibodies to fungal antigen
  • nasal polyps and other changes in their nasal and sinus cavities which can be seen using CT scans or MRI

Unlike some of the other types of fungal sinusitis, you do not have to have a weakened immune system (immunocompromised) in order to have allergic fungal sinusitis, as it often occurs in people with healthy immune systems.

You are however at a greater risk of having allergic fungal sinusitis if you already have allergic sinusitis.A culture alone will not tell you which type of fungal sinusitis you have, because the culture cannot tell you if the fungus has invaded the sinus tissue. For further clarification, CT or MRI can be used.

Treating Allergic Fungal Sinusitis

Even though allergic fungal sinusitis is an allergic reaction, your symptoms will not resolve with using antihistamines or other medications commonly given for allergies. This is most likely because the allergen, the fungus, is still trapped inside of the sinuses, causing a continual immune response which further perpetuates the condition. The only way for you to break the allergic cycle is to have sinus surgery. During sinus surgery, your sinuses are "cleaned out", the thick mucous containing fungal particles is removed along with any nasal polyps or diseased sinus tissue. Once the sinuses are opened up and able to drain properly, you can use any of the following strategies to help prevent a future episode of sinusitis:


American Acadamey of Otolaryngology - Head and Neck Surgery. (2015). Fungal Sinusitis. Accessed on January 7, 2015 from

Medscape. Allergic Fungal Sinusitis. Accessed: December 30, 2013 from

Medscape. Chronic Sinusitis. Accessed: December 30, 2013 from

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