First case report of oral histoplasmosis in a patient receiving Secukinumab (Cosentyx): opportunistic infections as complication of emerging immunomodulatory therapies.

Abstract

Introduction: Histoplasmosis is an opportunistic infection that can manifest in immunosuppressed patients, particularly those on biologic therapies.

Case report: This report presents a rare case of localized oral histoplasmosis in a 42-year-old Brazilian female undergoing treatment for ankylosing spondylitis (AS) with Secukinumab (Cosentyx), an interleukin-17 (IL-17) inhibitor. The patient presented with a painful, irregular gingival ulcer persisting for 4 months. Clinical examination revealed a 3 cm granular lesion involving the upper left gingiva. Histopathological analysis showed histiocytes containing yeast-like structures surrounded by a refractile halo, consistent with Histoplasma capsulatum by Grocott-Gomori methenamine silver staining. Chest computed tomography demonstrated no pulmonary involvement. Treatment consisted of oral itraconazole and discontinuation of Secukinumab, resulting in complete resolution of the lesion.

Conclusion: Oral histoplasmosis, despite being rare, should be considered in immunosuppressed patients with persistent oral ulcers. IL-17 inhibitors, while effective for AS, increase the risk of fungal infections due to impaired mucocutaneous immune responses. This case highlights the importance of vigilance, early diagnosis, and appropriate management in patients on immunomodulators. It also underscores the need for clinical awareness and further research into the long-term risks of immunomodulatory agents. This report contributes to the growing evidence on opportunistic infections associated with immunomodulatory therapies.