Abstract: Shiitake dermatitis is also known as flagellate dermatitis. The main clinical manifestations are striped and linear flagellate erythema. Most patients are accompanied by itching and have a history of eating mushrooms. We report three cases of shiitake dermatitis. Case 1 had a history of eating undercooked mushrooms twice. Case 2 had a history of eating plenty of flammulina mushrooms in sauce 48 hours before onset. Case 3 had a history of eating undercooked mushrooms one day before onset.