Pilot study of delayed hypersensitivity testing with fungal allergens in patients with allergic rhinitis and chronic rhinosinusitis

RATIONALE: Airborne fungi have been implicated as a possible cause of chronic rhinosinusitis (CRS), with mediation by sensitized lymphocytes. In this study, we have tested by patch testing, whether patients with CRS have lymphocytes sensitized to Alternaria and other airborne fungi. METHODS: Patch testing was performed with allergen extracts of Alternaria tenuis, Aspergillus fumigatus, Candida albicans, Curvularia spicifera, Helminthosporium, Hormodendrum, Penicillium, Trichoderma viride and Trichophyton rubrum on 23 patients with seasonal allergic rhinitis (SAR), 10 patients with CRS with history of previous sinus surgery for CRS, 13 patients with CRS with no history of sinus surgery and 24 healthy controls. Concentrations used for the patch testing were based on concentrations used for skin prick testing and concentrations used for immunotherapy. Two concentrations were used for each fungus. The patch tests were graded by dermatologists at 48 and 96 hours on a 0-4 scale. RESULTS: Of the 23 patients with SAR, 1 patient was positive to Alternaria, Candida, Penicillium and Trichophyton. Of 13 patients with CRS and no previous surgery, 1 was positive to Aspergillus. All 10 patients with CRS and previous sinus surgery for CRS were negative to testing. Of 24 healthy controls, 4 had positive responses to one or more of the allergens tested. CONCLUSION: In this study setting, we found no evidence of delayed hypersensitivity to fungal allergens in patients with CRS. The unexpected finding of positive patch testing to fungal allergens in healthy controls and SAR is puzzling and deserves further investigation.