Title : Shiitake mushroom-induced Flagellate Dermatoses A Rare Presentation In a Tertiary Hospital in Nepal: A Case ReportCorresponding author : Ashish TamangIntroductionShiitake mushroom-induced flagellate dermatoses, also known as flagellate erythema, is an intriguing rash associated with the consumption of raw or undercooked shiitake mushrooms (Lentinula edodes).1 While these mushrooms are widely appreciated for their culinary and potential health benefits, they can occasionally trigger an immune-mediated skin reaction in susceptible individuals. The characteristic rash manifests as intensely pruritic linear streaks, resembling whiplash marks, and typically appears within 24 hours to 5 days after mushroom ingestion.2The pathogenesis of shiitake flagellate dermatoses centers around a thermolabile polysaccharide called lentinan, which is present in shiitake mushrooms. Lentinan activates interleukin-1 secretion, leading to vasodilation, hemorrhage, and the distinctive rash.3 Notably, this flagellate dermatosis is not observed when mushrooms are thoroughly cooked at temperatures exceeding 145°C.4 As mushroom consumption continues to rise globally, recognizing this etiology becomes crucial, preventing diagnostic challenges and the recurrence of this characteristic rash.