Erythromelalgia associated with Clitocybe acromelalga intoxication.

Erythromelalgia is a rare disorder characterized by reddening, severe burning pain, and swelling of the extremities. Food poisoning by Clitocybe acromelalga, a poisonous mushroom, is known to induce erythromelalgia; however, its treatment protocol remains unclear. We describe here three cases of erythromelalgia following the consumption of C. acromelalga with varying clinical courses. Of the three patients, the first patient presented 22 days after the onset of erythromelalgia; although he was treated with aspirin, numbness in the limbs persisted as sequela. Patient 2 presented at 3 days after the symptomatic onset and was immediately treated with high-dose intravenous nicotinic acid, with a dramatic symptomatic improvement. Patient 3, who had milder symptoms, spontaneously recovered within a week without any treatment. The clinical manifestations and varying clinical courses associated with C. acromelalga toxicity are discussed here, with the pathogenesis of this mycotoxin and a potential treatment. Detailed interviews of such patients are important, particularly because of the remarkably slow course of this mycotoxin as compared with common food poisonings. Treatment with intravenous nicotinic acid was associated with improvement in one patient. We believe that this painful disorder might thus be treatable, although the mechanism underlying the treatment remains unclear.