Flagellate erythema as manifestation of food hypersensitivity

A Culinary Misadventure: A Case Report of Shiitake Dermatitis

“…8 Although the lesions may rarely present as petechiae, purpura, plaques, pustules, and even morbilliform, the notable flagellate lesions appear in nearly all cases. 3,8 It is uncommon, but possible, for patients to also experience fever, diarrhea, paresthesia, involvement of oral or eye mucosa, and dysphagia. 8,9 Although the exact pathophysiology is unclear, the rash is thought to be due to a toxic reaction to lentinan, a polysaccharide component of the mushroom that stimulates interleukin-1 which results in vasodilation and inflammation.…”

“…2 Because lentinan is denaturized around 130-145 degrees Celsius, it has been suggested that only exposure to raw or undercooked mushrooms would cause the dermatitis. 2,3,6 In one report, a patch test using mushrooms cooked at 100 degrees Celsius resulted in the skin eruption but not when the mushrooms were cooked at 150 degrees Celsius. 11 However, there have also been multiple cases of shiitake dermatitis after the consumption of cooked mushrooms 5,7 and even after drinking a beverage containing shiitake mushroom extract.…”

“…5 There is some debate as to whether shiitake dermatitis is truly the result of a toxic reaction. 3,[6][7][8] A few studies have demonstrated that certain human leukocyte antigen alleles and cytokine profiles make individuals more susceptible to generating a skin reaction when exposed to antigens, and an argument could be made that a similar connection could explain shiitake dermatitis although a specific marker has yet to be identified. 6,8 There is also some evidence that a T-cell reaction could also be the root of the rash.…”

“…1 With the growth in popularity of Asian cuisine and globalization of cultures, the international use of this delicacy has become so ubiquitous that it is now the second most cultivated edible mushroom worldwide. 2,3 Today, the mushroom is available fresh, dried, canned and as part of seasonings, supplements, sauces, drinks, and candy. 3 In rare instances, consumption of shiitake mushrooms has been associated with a dermatitis accentuated by linear erythema and considerable pruritus.…”

“…2,3 Today, the mushroom is available fresh, dried, canned and as part of seasonings, supplements, sauces, drinks, and candy. 3 In rare instances, consumption of shiitake mushrooms has been associated with a dermatitis accentuated by linear erythema and considerable pruritus. The presentation of this striking rash is uncommon with only an estimated 100 reported incidents since its first reported observation.…”