BACKGROUND: In the Pacific Northwest region of the US and in southwestern British Columbia, Canada, isolated cases of renal failure have occurred following ingestion of wild mushrooms. We report four cases in which toxic mushrooms were mistaken for the edible pine mushroom or matsutake (Tricholoma magnivelare). CASE REPORTS: Gastrointestinal symptoms started five to eight hours after ingestion and continued for several days. Three of the four patients were found to be in renal failure when they presented to the emergency department 5-6 days post ingestion. One patient, an elderly diabetic, had renal dysfunction the day following ingestion. All patients received hemodialysis and supportive care and regained renal function. DISCUSSION: Symptoms and time of onset are similar to those reported in previous cases of Amanita smithiana poisoning. This suggests that the mushroom involved in these cases may also be Amanita smithiana which contains nephrotoxic compounds. In one of the cases, stem ends of the mushrooms were available for examination. Cellular elements conforming to those described as being present in the species Amanita smithiana were seen on light microscopy. CONCLUSION: Mushroom field guides warn against mistaking Amanita smithiana for pine mushrooms. They are similar in size, color and habitat. It appears possible that Amanita smithiana mushrooms were eaten instead of pine mushrooms in these cases.
BACKGROUND: In the Pacific Northwest region of the US and in southwestern British Columbia, Canada, isolated cases of renal failure have occurred following ingestion of wild mushrooms. We report four cases in which toxic mushrooms were mistaken for the edible pine mushroom or matsutake (Tricholoma magnivelare). CASE REPORTS: Gastrointestinal symptoms started five to eight hours after ingestion and continued for several days. Three of the four patients were found to be in renal failure when they presented to the emergency department 5-6 days post ingestion. One patient, an elderly diabetic, had renal dysfunction the day following ingestion. All patients received hemodialysis and supportive care and regained renal function. DISCUSSION: Symptoms and time of onset are similar to those reported in previous cases of Amanita smithiana poisoning. This suggests that the mushroom involved in these cases may also be Amanita smithiana which contains nephrotoxic compounds. In one of the cases, stem ends of the mushrooms were available for examination. Cellular elements conforming to those described as being present in the species Amanita smithiana were seen on light microscopy. CONCLUSION:Mushroom field guides warn against mistaking Amanita smithiana for pine mushrooms. They are similar in size, color and habitat. It appears possible that Amanita smithiana mushrooms were eaten instead of pine mushrooms in these cases.