Changing Epidemiology of Mucoralean Fungi: Chronic Cutaneous Infection Caused by Mucor irregularis

Abstract

Introduction: The fungi pertaining to order Mucorales usually cause an acute form of clinical disease called mucormycosis. A primary chronic presentation in an immunocompetent patient is a rare form of mucormycosis. Mucor irregularis is known for causing chronic cutaneous infections geographically confined to Asia, mainly in China. We describe a case of primary chronic cutaneous mucormycosis caused by M. irregularis from a new geographical niche in India, highlighting changing aspects of its epidemiology.

Case presentation: The patient was a farmer with a history of skin lesions over the lower limb for the past 6 years. The biopsy taken from the lesions showed pauci-septate hyphae with right-angle branching on KOH wet mount as well as special fungal stains. On fungal culture, greyish-white cottony mycelial growth of Mucormycetes was obtained. The strain was finally identified as M. irregularis on macro- and microscopic features on 2 % MEA and DNA sequencing. The antifungal susceptibility was done using EUCAST broth microdilution method and was found to be susceptible to commonly used antifungal agents. The patient was started on oral itraconazole and saturated solution of potassium iodide (SSKI). While undergoing treatment for 2 months, he was lost to follow-up, however, after a year when he recently visited the hospital; the disease got completely healed with no new crops of skin lesions.

Conclusion: Mucoralean fungi should also be suspected in cases with chronic presentation, in immunocompetent host, as there is emergence of such fungi in new endemic areas, particularly located in Asia. The role of other antifungal agents apart from amphotericin B for the treatment of chronic mucormycosis needs to be explored.