Man gets rare ‘shiitake dermatitis’ from undercooked mushrooms

A man ended up in the emergency department with a painful rash that crosshatched his entire back after he ate a very common edible mushroom.

The 72-year-old man had prepared and eaten a meal containing shiitake mushrooms (Lentinula edodes). In the two days after this meal, the man developed a rash across his back that was so itchy he couldn’t sleep properly, according to a description of the case published Oct. 12 in The New England Journal of Medicine. When he went to the hospital, doctors examined his back and discovered that he had streaks of inflamed, swollen skin that looked as if he had been whipped across his back and the top of his butt.