Cross-reactivity between voriconazole, fluconazole and itraconazole.

WHAT IS KNOWN AND OBJECTIVE: Hypersensitivity to triazoles is a rare occurrence and cross-reactivity between agents is unknown. We present a successful voriconazole challenge in a patient allergic to fluconazole and itraconazole. CASE SUMMARY: A 41-year-old immunocompetent male with coccidioidomycosis developed fever, eosinophilia and maculopapular rash from fluconazole. Switching to itraconazole resulted in worsening of the rash and skin sloughing over 25% of his body. He was given an oral-graded challenge of voriconazole which he tolerated without incident. WHAT IS NEW AND CONCLUSION: This is the first report of a lack of cross-reactivity between itraconazole and voriconazole.