Shiitake dermatitis: the tale of an under-recognised, undercooked fungus
A 55-year-old man with no medical history or allergies presented in May 2015 with a widespread, pruritic, whiplash-like rash (Figure 1). On examination, multiple erythematous papules in a linear distribution, corresponding to areas of excoriation, were noted on his trunk, limbs, forehead and scalp. The rash had developed 12 hours after a meal containing fresh shiitake mushrooms. There were no associated systemic symptoms and the patient’s condition did not improve with topical administration of betamethasone dipropionate 0.05%. Based on dietary history and the characteristic appearance of the rash, a diagnosis of shiitake dermatitis was made. The rash resolved in 3 weeks without further treatment. The patient experienced a recurrence 5 months later, after eating another meal containing shiitake mushrooms.
A 30-year-old man with no comorbidities or allergies presented in March 2015 with a 2-day history of a striking, linear, erythematous eruption (Figure 2). He was systemically well, but reported associated perioral tingling and pharyngitis, which were unresponsive to 10 mg oral cetirizine. Examination revealed linear groupings of papules on an erythematous urticated base on his forehead and trunk. Despite denying pruritus or excoriations, relative sparing of the central back (out…