Allergic fungal sinusitis (AFS) is an allergic reaction to a fungus that causes significant swelling and irritation of the sinuses. Most people who have had AFS have a history of allergies that affect the sinuses, and 90 percent specifically have an allergy to some type of fungus. While not painful, AFS can cause chronic difficulty breathing and physical changes to the sinus cavities and face.
Significance
Many people suffer from allergies which often cause symptoms in the sinus cavities. For people living with chronic sinus congestion, the root cause may be an allergy to mold or fungus. One-third of these people will also suffer from asthma and many live with some other type of allergy. It is the reason for 7 percent of all surgery performed for treatment of chronic sinusitis.
Fungi thrive in moist environments and, accordingly, allergic fungal sinusitis is more common in areas where the humidity is high. In the United States, it is most common in the Southeast and Southwest as well as in the Mississippi Basin. AFS is most common in adolescents and young adults, with the average age at diagnosis being 21.9 years.
Symptoms
People with allergic fungal sinusitis suffer from nasal congestion, loss of smell, runny nose or rhinitis and postnasal drainage. The onset may be gradual with subtle to severe difficulty breathing. There may be severe obstruction of the sinuses that leads to changes in the face of the person, since the sinuses lie just below the surface of the face. Because the onset is gradual, these changes may be hard for even family members to recognize. Sinus headaches may be present. Pain in the sinuses themselves is usually not a symptom, but rather indicates that a companion bacterial infection may be present.
Identification
The criteria for diagnosing AFS have not been clearly established. The process involves X-rays of the sinuses to determine if there is swelling or changes such as polyps or changes to the bones of the sinus cavity, a biopsy or swab to determine if a fungus is present, allergy testing for an immune reaction to fungus, and the absence of another diagnosis. Ultimately, the diagnosis will be based on your doctor's best assessment.
Types of Fungal Sinus Infections
Fungi are part of a normal environment and are present in healthy sinus cavities. Three main types of fungal sinus infections represent circumstances where the normal flora is out of balance.
Fungal balls occur when fungus overgrows and accumulates, putting pressure on the sinus cavity and blocking the drainage of fluid. Fungal balls may require surgical removal.
Invasive fungal sinusitis is prevented by healthy immune systems, but may occur when a person is immune suppressed due to AIDS, poorly controlled diabetes, certain types of cancer or chemotherapy. Diagnosed by biopsy, in which a sample is taken and examined under the microscope, this can be a life-threatening condition.
Allergic fungal sinusitis may accompany polyps in the nose and significant nasal congestion. It commonly recurs because the allergy will persist once the treatment has ended.
Treatment
Corticosteroids and antihistamines may reduce the swelling of the sinus cavity. Antimycotics, or antifungals, may be used to kill the fungus. Antibiotics may be used to treat coexisting bacterial infections. A saline wash may be used to irrigate the sinus cavity, creating a hostile environment for fungi. Anti-sensitization treatments such as allergy shots or other alternative techniques may be used to reduce the body's reaction to the fungus. Surgery may be necessary to expose and remove the fungus and cleanse the area. Recurrence is common, even when multiple measures are used.
References
- The Merck Manuals: Online Medical Library; Sinusitis. Fried MP. July 2008.
- International journal of immunopathology and pharmacology; Treatment of rhinosinusitis: other medical options. Incorvaia C and Leo G. Jan-Mar 2010;23(1 suppl):70-3.
- Archives of Otolaryngology--head and neck surgery; Allergic fungal rhinosinusitis: an attempt to resolve the diagnostic dilemma. Saravanan K et al. Feb 2006.;132(2):173-8.
- Family Practice Notebook; Allergic fungal sinusitis. Moses S. March 2010.
