What we now know about allergic fungal sinusitis

Allergic fungal sinusitis (AFS) is thought to be an immunologic rather than an infectious process triggered by inhalation of fungi. Most patients with AFS are immunocompetent and atopic, and about 50% have asthma. Patients typically present with extensive nasal polyposis, chronic sinusitis, and recalcitrant disease. The most characteristic finding is allergic mucin in the sinuses; this must be submitted for histopathologic examination, with appropriate fungal stains. The accumulation of allergic mucin leads to the formation of mucocele-like cavities, causing eventual bone remodeling or erosion. Surgery is recommended to remove diseased tissue and marsupialize the involved sinuses. Nasal and sinus irrigations minimize the need for postoperative debridement, but long-term follow-up is mandatory. Postoperative intranasal corticosteroids and immunotherapy with relevant fungal antigens may also be beneficial.