Medical treatment of allergic fungal sinusitis

Learning objectives: This review of allergic fungal sinusitis (AFS) will enable the reader to (1) differentiate AFS from the other forms of fungal sinusitis, (2) understand AFS pathophysiology, (3) recognize AFS clinical presentation, (4) prepare an effective treatment and follow-up strategy, and (5) avoid diagnostic and treatment pitfalls. Data sources: All English language MEDLINE articles that cross-referenced allergy, fungal, and sinusitis from 1983-present. Other MESH words referenced included: antibodies, fungal; fungus diseases; IgE; spores, fungal; rhinosinusitis. Additional referenced articles, published abstracts, and conference proceedings were also utilized. Study selection: All case reports, studies, and review articles. Results: Allergic fungal sinusitis is a distinct form of non-invasive fungal sinusitis. It is under-diagnosed, and incidence varies by region. Dematiaceous fungi predominate. In the southwestern United States, Bipolaris spicifera is the most common cause. Patients present with nasal polyps, rhinosinusitis, and occasionally proptosis. CT scans show hypertrophic sinusitis and often hyperattenuating allergic mucin within the sinus cavities. Extra-sinus extension of disease is common. Surgical histopathology shows eosinophilic-lymphocytic mucosal inflammation and inspissated allergic mucin containing non-invasive fungal hyphae. All patients are atopic and have positive allergy skin tests to the AFS organism. Total serum IgE levels are usually elevated. AFS immunopathophysiology is analogous to allergic bronchopulmonary aspergillosis. Treatment requires surgery, postoperative oral corticosteroids (OCS), and aggressive allergy management including allergen immunotherapy. Oral corticosteroids reduce disease activity and forestall the need for recurrent sinus surgery. Postoperative changes in total serum IgE mirror the clinical status and may predict disease recurrence. Patients should be cooperatively followed by the medical specialist and surgeon because early sinus surgery for recurrence, together with aggressive medical management, gives the best outcome. Conclusions: Allergic fungal sinusitis is a new allergic disorder with recognizable clinical and histopathologic findings. Treatment requires aggressive allergy management, postoperative OCS, monitoring of total serum IgE, and medical/surgical co-management.